About the Work
Essays by Wilhelm Wundt is a collection of philosophical and scientific writings that grapple with the most pressing intellectual questions of the late nineteenth and early twentieth centuries. Written by one of the founding figures of experimental psychology, the book spans a remarkable range of topics, from the fundamental nature of matter and the infinity of the universe to the relationship between brain physiology and mental life, and the proper tasks of an experimental psychology. The essays are unified by a central concern: the proper relationship between philosophy and the special sciences, and the conviction that philosophy must ground itself in empirical scientific inquiry rather than in speculative system-building.
The work is presented as a second edition, suggesting both its reception and the author’s continued engagement with the subjects it treats. Wundt writes as a scientist-philosopher deeply immersed in the latest research of his day—from the discoveries of Röntgen rays and radium to the debates surrounding the descent theory and the principle of the conservation of energy. He moves with ease between abstract epistemological questions and concrete experimental findings, between the history of ideas and the most current controversies in physics, chemistry, and physiology. The essays are not merely popularizations but serious attempts to think through the philosophical implications of scientific discovery, addressed to an audience of educated readers who share the author’s conviction that the boundaries between disciplines are artificial and that the deepest questions require the resources of both philosophy and science.
The book’s tone is that of a master lecturer and researcher who has spent a lifetime at the frontiers of knowledge. Wundt is critical of philosophical schools that isolate themselves from scientific progress, but equally critical of scientists who speculate beyond their competence without regard for epistemological rigor. He writes with the authority of someone who has helped create a new scientific discipline—experimental psychology—and who therefore knows firsthand both the possibilities and the limitations of applying scientific methods to questions traditionally reserved for philosophy. The essays reflect a mind that is encyclopedic in its learning, precise in its arguments, and passionately committed to a vision of unified knowledge that does not sacrifice empirical accuracy to metaphysical ambition.
Context
The essays emerge from a period of extraordinary intellectual ferment in German-speaking Europe. The mid-to-late nineteenth century had witnessed the rise of the special sciences to unprecedented independence and authority, a development that posed fundamental questions about the role and purpose of philosophy. Wundt writes against the backdrop of the collapse of the great speculative systems of German idealism—Schelling, Hegel, and their successors—which had attempted to derive the content of all knowledge from a priori principles. The failure of these systems had left philosophy in an uncertain position, unsure whether it should retreat to the history of ideas, confine itself to logic and epistemology, or seek a new relationship with the rapidly advancing empirical sciences.
At the same time, the sciences themselves were undergoing revolutionary transformations. The principle of the conservation of energy had been established as a cornerstone of physical theory, and the descent theory of Darwin was reshaping biology. These two great generalizations, as Wundt notes, had philosophical implications that extended far beyond their original domains. Natural scientists themselves began to construct metaphysical systems on scientific foundations—Ostwald’s energetics, which sought to reduce all phenomena to transformations of energy, and Haeckel’s monism, which drew sweeping philosophical conclusions from evolutionary theory. Wundt observes this development with a mixture of sympathy and alarm: sympathy for the philosophical drive that animates it, alarm at the naivety with which scientists often speculate beyond their competence.
The period was also marked by dramatic discoveries that seemed to undermine long-cherished certainties about the nature of matter. The discovery of X-rays, of radioactivity, and of electrons suggested that atoms were not the indivisible, indestructible units that nineteenth-century chemistry had assumed. Radium, which constantly emitted energy and appeared to decay into other elements, challenged the very concept of chemical element. These discoveries opened a perspective of “total upheaval” in fundamental ideas, and Wundt engages with them not as a detached observer but as a philosopher who recognizes that such empirical developments have profound implications for our understanding of reality.
The essays also reflect the institutional and disciplinary context of their time. Wundt was a professor at Leipzig, where he had established the first laboratory dedicated to experimental psychology. He was therefore at the center of efforts to create a scientific psychology independent of both philosophy and physiology, yet he insisted that psychology remained essential to philosophy—that the philosopher who ignored psychology and logic was as deficient as the specialist who ignored neighboring fields. This position put him in conflict with those who saw philosophy’s task as confined to the determination of values and norms, and with those who believed the division of intellectual labor made any synthesis impossible. The essays are thus interventions in a live debate about the future of philosophy and its relationship to the sciences, a debate that continues to resonate.
Structure of the Book
The book is organized as a series of essays, each addressing a distinct but related set of problems. The opening essay, “Philosophy and Science,” establishes the fundamental theme that runs throughout the collection: the proper relationship between philosophical inquiry and the special sciences. Wundt traces the historical development of this relationship from Kant through Fichte, Schelling, and Hegel, showing how the attempt of speculative philosophy to dominate the sciences led to an unnatural separation. He argues for a conception of philosophy as a “science of sciences” that takes the whole extent of scientific experience as its foundation, rather than a discipline that either dictates principles to the sciences or retreats to a separate realm of values and norms.
The second essay, “The Theory of Matter,” is a substantial historical and critical examination of atomic theory. Wundt traces the development of atomism from its origins in the corpuscular philosophy of Descartes and Boyle through Dalton’s chemical atomism, the wave theory of light, and the kinetic theory of gases. He examines the evidence for atoms from chemical combination, gas expansion, and the phenomena of isomerism, and he considers the philosophical questions raised by different conceptions of the atom—whether atoms are mathematical points or extended bodies, whether they are absolutely rigid or elastic, whether they are ultimate or themselves composite. The essay culminates in a discussion of the revolutionary discoveries of the late nineteenth century—cathode rays, electrons, X-rays, and radioactivity—which suggested that even the chemical elements might not be eternal and indestructible.
The third essay, “The Infinity of the World,” addresses a question that has occupied philosophy since its beginnings: whether the world is finite or infinite in space and time. Wundt begins with the cosmological ideas of the ancient Greeks, moves through the medieval and early modern period, and arrives at Kant’s treatment of the antinomies in the Critique of Pure Reason. He argues that the causal series of the world-process is not infinite but merely immeasurable, bounded by an initial and a final point, and he examines the implications of this view for our understanding of space, time, and matter. The essay concludes with reflections on the limits of human knowledge and the indeterminate character of any conclusions about the universe as a whole.
The fourth essay, “Brain and Soul,” examines the relationship between cerebral physiology and mental life. Wundt traces the history of attempts to localize mental functions in the brain, from Descartes’ identification of the pineal gland as the seat of the soul through the faculty psychology of Christian Wolff and the phrenology of Gall, to the more sophisticated localization studies of his own time. He argues that while the brain exhibits a division of labor, with different functions bound to different regions, this does not justify the conclusion that complex mental activities like language are localized in specific areas. He criticizes the tendency to treat ideas as things that can be deposited in cells and to assume that the brain contains a fixed inventory of mental faculties.
The fifth essay, “The Tasks of Experimental Psychology,” marks a transition from the critical and historical mode of the preceding essays to a constructive program. Wundt argues for the possibility and necessity of an experimental psychology that applies the methods of natural science to the study of mental processes. He addresses the objections of those who believe that consciousness cannot be studied experimentally, and he outlines the kinds of questions that such a psychology can address. The essay reflects Wundt’s conviction that psychology is both a science in its own right and an essential foundation for philosophy.
The remaining essays continue to develop these themes, exploring the relationship between psychology and philosophy, the nature of scientific explanation, and the implications of recent discoveries for our understanding of mind and world. Throughout, Wundt maintains a consistent stance: philosophy must be empirical without being reductionist, scientific without being dogmatic, and critical without being skeptical. The book as a whole is a sustained argument for a conception of philosophy as a discipline that grows out of the sciences and returns to them, clarifying their concepts, resolving their contradictions, and unifying their results.
Inside the Book
Philosophy and Science
The chapter opens mid-argument on Kant’s critical philosophy, explaining how Kant distinguished between two realms of inquiry. Concepts of the external world, he argued, must first become appearances within our consciousness before we can know them. Because these concepts precede all experience, they yield principles that are valid a priori for all possible experiences, a discipline Kant called the “Metaphysik der Natur.” Separately, the fact of the freedom of the will—which reveals our own inner essence—could be examined for its consequences regarding the moral world, producing the “Metaphysik der Sitten.” Though these two domains nominally leaned on the old metaphysics, their content actually corresponded more closely to English epistemology and moral philosophy, cautiously limiting themselves to the highest principles of empirical natural knowledge and empirical morality. Yet the fundamental conception was different, and here German metaphysics broke through: Kant held that the general principles of natural explanation precede all individual experience, and that the moral law is an internal rule effective in each moral action yet independent of all motives of experience and sensual inclination.
This boundary regulation was clearer than in older metaphysical schools, but whether it could be maintained to mutual satisfaction was questionable. Natural science soon had to discard Kant’s general theories as incompatible with experience, while jurisprudence struggled with his rigid moral imperative and severe views on imputation and retribution. Kant himself, especially in his legal doctrine, made considerable incursions into special research. These incursions increased rapidly among his successors, even as the special sciences began their process of independence, leading to what the author calls the current intermediate state of “a philosophy of philosophers and a philosophy of specialists.”
Kant’s immediate successor, Fichte, still held to those boundaries, even attempting to define them more precisely. He called his philosophy “Wissenschaftslehre,” tasked with developing all general scientific propositions a priori. Each derived proposition of the Wissenschaftslehre was, he said, simultaneously the highest principle of some special science, which gains its content by applying that principle to experience. Schelling and Hegel, however, were not content with this modest task. Schelling, who occasionally prescribed medical recipes according to his Naturphilosophie, sought to restore the unity of science in a Platonic spirit. Hegel applied his whole tenacious energy and fearless consistency of thought—in which boldness and depth of ideas were wonderfully mixed with stiff pedantry of form and a fondness for a spirit-killing schematism—to this same task.
The Hegelian system satisfied all needs for those who surrendered to it; there was no general or individual question it did not answer. But since the living stream of scientific development continued regardless of this dialectical artwork, the world one day found itself in possession of two scientific systems that both wanted to encompass the same content of concepts and facts yet differed totally in form and method—like a green primeval forest on mountain heights and the floating raft built from its trees. The result of striving for unity of science was that the philosophical and scientific systems had become two different sciences sharing nothing but names. Some of Hegel’s philosophical contemporaries and opponents—such as Herbart or Schopenhauer—were more moderate and sometimes friendlier to positive research, yet they conceived philosophy’s position toward the special sciences no differently than Schelling and Hegel, and their actual relationship remained essentially unchanged.
That this relationship has become untenable is shown by success. The attempt to regain philosophy’s ancient supremacy has resulted in philosophy finding itself outside the sciences rather than above them. It is a false excuse, contradicting the real unity-needs of human thought, when today’s philosophers justify this situation by claiming there are two distinct ways of knowing objects: the ordinary one used by the special sciences, and a special higher one to which philosophy rises. Either the first way is false or the second; there is no third. Either the philosopher has not fully possessed the facts commanded by scientific experience, or the specialist has neglected to consult psychology and logic and to heed neighboring fields. In both cases, the dissonance between philosophical and scientific consideration can and must be resolved; philosophy’s task should be to get to the bottom of contradictions between different fields of knowledge and, if possible, eliminate them.
Since the special sciences emerged as branches of old philosophy, a reversal occurred, especially from the Renaissance onward: philosophy received its fertilizing thoughts from individual fields, mostly mathematics or natural research. The transient attempt of nineteenth-century speculative systems to reconquer philosophy’s ancient position could not stop this development; indeed, that attempt itself never fully escaped it. The goal of this development is evidently that philosophy should no longer merely furtively and accidentally follow the stimuli of special research, but should take the whole extent of scientific experience as its foundation. Only then will it become Wissenschaftslehre or “science of sciences” in the true sense, continuing and completing the work begun by special research.
The Metaphysical Drive Within Natural Science
That such a general science is necessary is proven not only by the philosophical drive stirring within special research—more alive today than long before—but above all by the demand for unity. A remarkable symptom of this is the attempt to construct a new metaphysics on a scientific foundation. This turn toward a system extending far beyond natural philosophy into ethics, aesthetics, and even religious philosophy followed a reaction, around the mid-nineteenth century, against the earlier timid rejection of questions beyond narrow special problems. This reaction, which heralded the philosophical spirit of the new age, expressed itself in two great generalizations that revolutionized scientific ideas: the principle of the constancy of energy and the descent theory. The author notes that tracing their influence on nineteenth-century philosophy will be a task for a future historian; here, he only points to their role in metaphysical system-building attempts within natural science itself.
In the case of energetics, this rise to metaphysics grew gradually from the attempt to secure the energy principle’s dominance over the previously favored mechanical-atomistic view. Like a conqueror’s greed growing with success, energetic natural philosophers were not content with applications in physics, chemistry, biology, or speculations on the universe’s future and end. These were only the timid beginning of further undertakings, whose seed lay hidden in the energy principle’s universal significance. Ostwald’s “Lectures on Natural Philosophy” extended far beyond its title into psychology, aesthetics, and ethics, treating them as tributary provinces of a general energetics. This manifestation of the energy principle’s metaphysical drive toward unity is not isolated; similar ideas are widespread among naturalists and philosophizing dilettantes inspired by energetics.
The second form of modern scientific metaphysics, arising from the descent theory, is likely even more popular among the latter, partly due to its easier comprehensibility and its greater vagueness, which gives fantasy wide scope. Haeckel’s “Riddles of the Universe” shows immense distribution, boldly displaying the character of an all-encompassing philosophy. A notable symptom of this era is that naturalists who worked in one principle’s domain often reject its far-reaching metaphysical conclusions, only to find the desired complement in the other principle, which is farther from their own research. Thus, among biologists, a strong opposition arose to Darwin’s form of the descent theory. Some leaders of this opposition aim for a renewal of vitalistic ideas to place developmental and descent theory on a new basis. In this striving, they believe they find help in energetics, which also seeks to eliminate mechanical theories, to prevent a conflict with the exact sciences. The energy law’s wide scope for qualitatively different energy forms leaves room for specific life energies, whereas mechanics, as sole ruler, would reject such newcomers.
An interesting counterpart is the position of some theoretical physicists toward both principles.
The Theory of Matter and Its Discontents
The passage opens by observing that while the electromagnetic theory of light sought to extend mechanics, other scientific fields came to feel that the principle of the conservation of energy was independent of the restrictive conditions of mechanical reduction. The theory of heat had already used this principle to make its most general propositions independent of any specific ideas about the motion underlying heat phenomena. General heat theory and kinetic heat theory thus appeared as two disciplines of the same field, the latter being both more specific and more hypothetical, which led to a call for a heat theory that dispensed with kinetic hypotheses entirely. Physical chemistry soon joined this movement, finding energetic viewpoints applicable to all phenomena where mechanical interpretation remained uncertain, especially in “catalytic processes,” where one body acts chemically on another without itself appearing to change. Physiology had long used the energy principle as a fruitful heuristic maxim for examining the exchange of substances and forces in organisms, as no other path was available given their complexity.
This prepared the ground for a scientific movement originating from physical chemistry that spread into pure physics. This movement sought to treat mass and velocity-squared in mechanics not as independent concepts but only as factors of energy, with complementary factors for other natural phenomena, ultimately aiming at the complete abolition of the concept of matter and all hypotheses about it. Natural science was to become a description of energy forms given in perception and their transformations—a reversal analogous to the Renaissance decline of Aristotelian physics, but in the opposite direction. Outsiders like theologians and philosophers welcomed this, mistakenly believing materialism would vanish with matter—a conceptual confusion. Natural science itself reacted differently: chemists and biologists favored it, while physics proper mostly rejected it, partly due to difficulties in executing the energetic program and partly due to new observational facts demanding a revision of views on matter and new hypotheses about its constitution.
The Discovery of Rays and the Instability of Elements
These new facts again lay in optical and electrical phenomena. First were the rays discovered by Röntgen, produced by rays from the negative electrode (cathode) in an evacuated glass tube, led outside through a thin metal foil on the positive electrode side, and caught on a screen. These cathode rays, first led outward by Lenard, are invisible but make a fluorescent screen glow. Röntgen unexpectedly found they penetrated the screen and other opaque bodies, affecting photographic plates and casting shadow images. Beyond their practical importance, they raised the theoretical question of their nature, pointing back to the phenomena at the negative pole of the evacuated tube. These had been observed long before by Hittorf and Crookes but not closely studied. Stimulated by Röntgen’s experiments, Goldstein and Lenard found rays from the positive electrode (anode) moving toward the cathode, which could be led outward if the cathode metal was perforated. Further experiments showed cathode rays are not electrical waves but a stream of negative electricity particles, torn from atoms, which charge conductors and air negatively. The anode rays, or “Kanalstrahlen,” consist of positive particles. These isolated particles were called electrons, distinguished as positive and negative. This suggested Röntgen rays are light waves generated by negative electrons striking the screen, oscillating longitudinally, which allows them to pass through solid bodies.
A second series of discoveries followed. Becquerel found that uranium compounds emit invisible rays affecting photographic plates and charging air. Frau Curie isolated radium from uranium ores, which possessed these properties to a heightened degree, enabling closer study, mainly by Rutherford. Radium constantly emits electrons, mostly positive, fewer negative, producing light, heat, and charges. Positive electrons create stronger charges but adhere more firmly and move slower; negative ones approach light speed, and some penetrate thick opaque layers, seemingly related to Röntgen rays. Radium also emits a gaseous substance that decays into helium (identified by Ramsay in the sun, stars, and minerals) and a solid residue emitting more electrons. Radium thus is not an unchangeable element, and since it likely comes from uranium’s splitting, uranium too is unstable. The same applies to polonium and actinium, found in uranium ores. Since radium constantly emits heat, it must have a limited lifespan, though estimates vary widely. Radium is among the most labile elements, so these numbers are likely minima, possibly explaining their rarity. All elements may undergo similar decay, even without radiation, if electron motion is too slow for measurable effects. This opens a perspective of total upheaval: the supposedly unassailable principle of the indestructibility of chemical elements wavers, becoming a relative, though generally useful, empirical law rather than an absolute axiom.
The Phenomenological Standpoint
The passage then compares this empirical development with changes in general ideas about matter’s nature. When Maxwell proposed his electromagnetic vortex theory, no one, least of all himself, took the mechanism for reality; he later let such ideas recede, keeping only the equations as abstract foundations. This “phenomenological” standpoint, named after Ernst Mach, was supported by H. Hertz’s work, which Maxwell’s formulas inspired. Energetics accepted this principle, renouncing mechanical pictures. The renunciation of intuitive picturability became a program, though the term “phenomenological” ironically coincides with the intuitive, since the aim was to return to actual appearances given in sensations. Natural science, however, seeks to connect these disconnected sensations, using mathematical equations as a tool due to the compelling character of arithmetic, not due to any intuitive meaning. Thus the phenomenological concept transformed into its opposite: an abstract symbolism and automatic technique. The motive of intuitive picturability, emphasized in an essay from 1875, seemed eliminated. That earlier view held that natural phenomena, belonging to intuition, must be derived from assumptions about an intuitive substrate; now intuition was renounced entirely, forgetting this is impossible because perceptions are given in space and time, and processes connecting them can only be conceived in space and time.
The Limits of Causal Knowledge
The theory of matter undergoes constant changes in its execution, even if its foundations remain. These changes are not continuous like the general progress of natural knowledge; the architectural coherence of a theory often lets hypotheses persist beyond the time when they have lost their justification. This explains why the theory of matter is especially prone to dogmatic rigidity, characterized by confusing hypothetical elements (even those permanently hypothetical) with facts themselves. The great upheavals preceding the recent regeneration of atomism have recalled the distinction between hypotheses and facts. The concept of matter is indispensable but remains fundamentally a hypothetical concept.
The causal series of the world-process is not infinite for our understanding, but merely immeasurable, bounded by an initial and a final point. This view is confirmed by astronomical and physical hypotheses. Although the temporal infinity of the world is generally asserted, no one has successfully dissolved observable natural phenomena into an infinitely regressing causal chain. Aristotle seems to make such an attempt, but it predates the exact theory of causality and actually supports the claim. Aristotle taught an eternal revolution of the heavens, from which all other movements supposedly proceed, but he called this revolution itself causeless. Since this causeless movement continually generates other movements, his view is not that the causal series extends infinitely backward, but that it perpetually begins anew. Only the causeless event is eternal; all causal events have a definite point of origin.
Modern fantasies of an oscillating world-process are too poorly grounded to consider and have not entered science. The hypothesis of Kant and Laplace, developed independently, about the beginning of our planetary system still holds. It posits an original nebular ball from which rings detached, condensing into spheres, a process that could repeat. The first spheres formed planets, secondary ones their moons.
The Speech Center and the Seat of the Soul
The discussion of brain physiology deepens by confronting the principle of division of labor with the apparent exception of language. No single point in the brain governs all functions, and seeing, hearing, touch, and movement are each distributed across different central substrates, just as they are on the body’s surface. Complex performances, therefore, must arise from the cooperation of numerous central elements. The localization of language seems to contradict this, as it appears bound to a specific cortical area. However, this knowledge is crude. A significant finding distinguishes two forms of central speech paralysis: in one, words are no longer understood but can be repeated; in the other, understanding is preserved but articulation is lost. These correspond to lesions in different parts—word comprehension tied to the temporal region, word formation to the lateral frontal region. Other disorders affect reading and writing, and each function that can be lost in isolation likely has a separate substrate within the general central language area.
The removal of a specific cortical region does not allow us to localize the will there, but only suggests that the intermediate links for transmitting will-impulses are removed. Similarly, the so-called speech center is an area whose removal abolishes speech, but this does not justify calling it the seat of the speech faculty. This would be like saying a specific screw in a clock keeps it running because the clock stops when the screw is removed. The assumption that a complex activity like language is bound to a strictly limited central region is untenable, since simple sensations of sound and light, and simple voluntary movements of articulation and writing, are also required and have their own separate central representations. The speech center likely contains only transitional links or junction points whose removal disrupts the common action of numerous diverse elements.
A notable phenomenon is the gradual restoration of functions after brain injury, which can be complete even if the lesion persists. Some physiologists saw this as contradicting localization and returned to Flourens’s view of the equivalence of all brain parts. However, this is unjustified; one can only conclude that localization is not absolutely unchangeable, and other parts of the brain can gain the ability to substitute for lost functions. This law of substitution is an important supplement to the doctrine of division of labor. Examples include a person without arms learning to write with the right foot, and the adjustment of double vision in squinters. Such adaptation is found throughout the organism, providing indirect proof that composite abilities like the “language faculty” are not localized as such, but arise from the complex cooperation of simple processes bound to specific central elements.
This leads to two general questions: what view do new experiences about the brain’s physiological significance lead to, and how does this view address the old problem of the interaction between body and soul? Physiologists have generally concluded that the elements of the cerebral cortex are the bearers of the simplest mental activities, primarily the bearers of ideas. Localization of brain functions is thus equivalent to the localization of our ideas. Light, sound, touch, and movement ideas are deposited in different regions of the cortex, with connections between them made possible by central nerve fibers. A specific part of the central visual area is thought to mediate clear perceptions, and in the occipital lobes whose destruction abolishes clear vision, memory images are supposedly deposited, while other parts contain cells vacant for new impressions. After the loss of memory cells, new memory images can be fixed in remaining cells, explaining gradual recovery. Similarly, hypotheses regarding central speech disorders suggest that sound images of words are deposited in certain cells, written images in others, ideas of articulation movements in a third group, and ideas of writing movements in a fourth. A fifth region is often assumed, whose cells connect with all the previous ones, where concepts reside.
The author notes the concern that an idea might find all places occupied, but this is unfounded. The entire human brain cortex is estimated to contain 612,112,000 nerve cells. According to Max Müller, even Shakespeare had only about 15,000 words, while an ordinary person uses 3,000–4,000. Even accounting for wordless ideas and that each idea may be fixed in 4–6 forms, there seems to be an abundance of space.
The Metaphysical Standpoint
The author argues it would be rash to think one can overcome the standpoint of popular metaphysics through a logical conclusion. Descartes’ physiological ideas, where all nerves converge in the brain to act on the soul, have been irrevocably eliminated by brain physiology. Leibniz gave the Cartesian view a form independent of temporary physiological knowledge: the soul, inaccessible to physical impressions, is in reciprocal relation with all other beings through the original harmony of the universe. This hypothesis underwent changes: Christian Wolff removed the idea of the soul’s connection to the infinite universe, finding an original adaptation of the mind’s ideas to the body’s states sufficient. Later, Herbart sought to replace the mystical idea of pre-established harmony with a form of interaction, imagining the soul-monad as mobile. Lotze noted these wanderings are unnecessary if one ascribes to the soul the ability to inwardly sense what occurs outside it in forms determined by its own nature.
None of these hypotheses face difficulties from physiological knowledge; even the idea that human souls are gathered on Sirius would face no obstacles. Metaphysics, as it actually influences popular psychological views, is in an enviable position: since its assumptions go beyond all experience, it is kept independent of experience’s progress. The empiricist sees views constantly corrected, while the metaphysician works for eternity. This supposed inaccessibility has a downside: the more unassailable hypotheses are to experience, the less influence they have on it. The doctrine of the soul’s punctual seat in the brain has not advanced inner experience. The author believes the error lies in mixing two standpoints: outer experience (taken by natural science) and inner experience (taken by philosophical epistemology). The metaphysician rightly views the soul as a unified being from inner experience but wrongly transfers this to outer experience, making the soul a simple, indivisible object—an atom, usually called a monad. Leibniz warned against thinking of monads spatially, but the monad remains a spiritualized atom. One should be prevented by the phenomenal nature of space from making the soul, whose activity produces space, into a spatial thing.
From the standpoint of outer experience, there can be no talk of a place of the soul, as mental activities never appear in outer experience; only physiological processes accompanying mental life can be localized, and these are not concentrated at one point but involve the whole body. From the standpoint of inner experience, our entire conception of the outer world, including space, is a product of our consciousness. This does not mean the world is a deceptive appearance; objects are given, but our conception of them depends on ourselves. Outer and inner experience are not equivalent. Objects of outer experience must be mentally appropriated; our own thinking and feeling is the only immediate object of knowledge. Therefore, one cannot speak of a seat of the soul; the soul is nothing other than this thinking and feeling itself, to which one cannot ascribe shape, color, or tone. Mental being, as the only object of immediate knowledge, is also the more certain and ethically more valuable. A series of inferences leads to the conviction that we are surrounded by similar mental beings, a conviction that makes life worth living.
The Tasks of Experimental Psychology
A note states that the essay on this topic appeared shortly after the one on the theory of matter in the “Deutsche Rundschau.” New discoveries in brain anatomy and physiology, building on Theodor Meynert’s work on pathways and experiments by Hitzig, Ferrier, and others, raised bold expectations.
Phrenology’s Decline and Its Lessons
The critique of phrenology continues by noting a fatal flaw in its system: the so-called organs of the mind were located on the skull, where the bone’s shape is determined not by the brain beneath it but by its own thickness and even by air spaces within the bone. The movement’s propaganda, which a forgotten humorous novel by Langbein satirized, closely resembled the earlier physiognomic craze. It was promoted by wandering prophets who hailed it as the science of the future, hoping to reform state and society. The key difference was that Gall, phrenology’s founder, came from medicine rather than the pulpit. His four massive folio volumes relate to Lavater’s fragments as a dry anatomical compendium relates to a collection of sermons—pedantic prolixity posing as scientific thoroughness.
This spectacle of pseudoscience caused serious scientists to transfer their distrust onto the very question of emotional expression. About sixty years earlier, Johannes Müller, the era’s most significant physiologist, had declared that why certain mental states manifest in specific bodily movements was entirely unknown. Only recently had these neglected border regions between humanity’s outer and inner life received attention. Emil Harleß, in his anatomical work for artists, discussed individual expressive forms, emphasizing eye movements and skin sensations tied to facial muscle tensions. Piderit attempted to show that mimetic movements are determined partly by imaginary sense impressions and partly by imaginary objects. The French anatomist Gratiolet developed similar views in his lectures, and Darwin compiled extensive observations on the expression of emotions in humans and animals.
The Insufficiency of Darwin’s Principles
While these authors’ propositions contain some truth, they neither account for the full richness of expressive movements nor trace them to their ultimate psychological ground. Darwin demonstrated two important facts: the general uniformity of expressive movements across human races and even broader agreement among different animals, and the inheritance of specific individual expressive forms from parents to offspring. However, his three general principles for deriving all expressive movements are unsatisfactory. His first two principles—”serviceable associated habits” and “antithesis”—reduce to a single psychological ground: habit. We habitually examine objects with both eyes, so the fixing gaze supposedly associates with attention generally. A house dog signals hostility by raising its head, tail, back, and neck; friendliness therefore expresses in exactly opposite movements.
But habit ultimately explains everything and therefore nothing. We eat, drink, speak, and act from habit. It belongs to concepts that merely designate a gap in our insight without filling it. “Association from habit” tells us a connection exists, not why it exists. Even accepting habitual connection, it would not follow that an opposite mood must be accompanied by opposite movements. Darwin’s third principle, that certain expressive movements arise as mechanical results of excitations through the nervous system’s interconnections, is generally correct but should be reformulated so that the “constitution of the nervous system” does not appear merely as an unknown quantity explaining whatever lacks convenient explanation otherwise.
The Law of Connection of Similar Feelings
Rather than exhaustively describing the infinite variety of expressive movements, Wundt highlights key psychological viewpoints. Foremost is the fundamental law of inner experience: similar feelings and sensations connect with one another. Aesthetic or moral satisfaction connects with sensory pleasantness. We relate sensations from different senses, and language shows this: we speak of tone colors and color tones, sweet melodies and sharp dissonances, bitter need, sour gait, sweet idleness, hard decisions, heavy sorrow, gnawing care, dark fate, black fears. These metaphors have a basis in feeling: under heavy fate we genuinely carry a feeling like physical pressure; violent anger relates to the taste of swallowing bitter medicine. Language transfers mental states into sensory forms because inner emotions themselves connect with sensory feelings similar to those accompanying sense impressions.
Sense organs lie at the body’s outer surface, equipped with muscles that facilitate or protect sensory reception. Movements arising thus are accompanied by sensations—every movement mirrors itself in consciousness as a muscle-tension sensation, providing the precise measurement needed for voluntary bodily control. Such sensations arise in mimetic movements too, intimately connected with the external sense impressions whose effects they originally were. We cannot express sweet or bitter taste with our mouth without faintly re-experiencing the taste; frowning vertically and half-closing the eye evokes something vaguely recalling glaring light. Through this indissoluble connection, mimetic movement awakens the same sense impressions in external observers, letting them feel with us. This is the source of the irresistible force, especially in children and natural peoples, with which expression transfers emotion itself—a purely sensory source of pity and shared joy, probably more valuable for moral development than the most forceful pedagogical admonition.
Through the law of analogous feeling-connection, inner states of fear, sorrow, and joy attract not merely weak copies of sensory feelings but also the movements and movement-sensations corresponding to the sense organs’ natural reactions. Thus mimetic movement, originally indicating only the sensing organ’s behavior toward sensory stimuli, becomes the general expression of feelings. Feeling anger or sorrow, the mouth assumes the position as if a bitter or sour substance touched the tongue; the eyelid forcibly lowers, the eyebrows press inward, the forehead wrinkles vertically as if protecting the eye from unpleasant glare; even the nostrils depress as if warding off a disturbing smell. In opposite moods—hearing a pleasing melody, an amusing story, joyful news—the mouth takes the form a sweet taste produces; the eye and nose open as if all senses opened their gates to receive the impression; the forehead is smooth or horizontally folded from raised eyelids.
The Error of Imported Concepts in Language Theory
Wundt turns to a new subject, beginning with one of our most common errors: importing concepts into objects of reflection that are mediated by a reflection entirely foreign to the things themselves. This error has persisted most stubbornly in ideas concerning the beginnings of human society. Law and custom, religion and language are handed down as finished creations; we learn they have changed over time but never that they once originated. This produces the notion that all these creations arose as we see binding laws arise today—as inventions of individual lawgivers of superior power and insight. Even language, the earliest product of the human mind, is traced to an original language-maker or a language-inventing community. Once reflective consciousness grasps the difference between word and concept, the word appears as an external sign that could be devised for existing concepts, like algebraic symbols. When the difficulty of this view is seen, people do not reject the idea of invention itself but only doubt that humans are capable of it—leaving only the alternative of seeing language as a work of superhuman insight, a direct gift of God. The ancients debated whether language arose by nature or by convention, and this oscillation between human invention and divine inspiration persisted nearly into modern times.
These assumptions were most eagerly discussed in the second half of the eighteenth century, though the idea of development had barely entered linguistics and psychology. It is not rare in intellectual history that people strive most eagerly over the most general problems of a science precisely when that science is only coming into being. Herder, the most spirited representative of this language philosophy, embodied both directions: in his early work On the Origin of Language he sought to understand language as natural invention, but in later works he turned to belief in divine origin. Both views agree in assuming an original state where humans lacked language. Wilhelm von Humboldt’s enduring merit was recognizing that language is as much cause as effect of thinking, and above all that it is not a finished tool standing ready for arbitrary use, but consists in the very mental activity through which it is continually produced.
Wundt doubts whether modern views have entirely eliminated the older contrasts.
The Development of the Will
The essay begins by considering the origins of voluntary action. Animals and humans enter the world with purely mechanical bodily movements that are not only involuntary but initially unconscious. These arise partly as reflexes from accidental stimulation of the skin and other sensory areas, due to the connection of sensory and motor nerve fibers in the central organs, and partly from direct physiological stimulation of the nerve centers, called automatic movements. It is conjectured that changes in blood flow or blood quality are the main causes of such automatic stimulation. It is further assumed that these reflex and automatic movements are first transformed from unconscious into conscious ones: through the eye, and through touch and muscle sensations, perceptions and ideas of the movements arise.
Once this has happened, the will appears at the right moment. It tells itself it can use the previously unintended movements for its own purposes, making them voluntary. The will seizes them, not waiting for reflex or blood stimuli, but producing them as needed, guided by experiences gathered from observing involuntary movements. Initially clumsy, it practices and gradually can invent new combinations, enabling actions not originally provided for in the purposeful organization of the nervous system. The author notes this description is not exaggerated and is found nearly verbatim in psychological accounts. Sometimes, to avoid presenting the will as an observing, deliberating being, this task is transferred to the soul. The soul notices that a chance movement has a purposeful effect and prompts the will to repeat it.
The author argues the difficulty remains the same whether one follows the “oligarchic” or “monarchic” system. The soul is supposed to notice that movements are subject to its rule, but how can it notice this rule without already having the will that exercises it? Either the will is original—then it need not be derived from involuntary activities—or it is not original—then it cannot be derived from them. How the soul could know that movements of its own body are subject to a will that does not yet exist is incomprehensible. The author also calls it an exorbitant demand to imagine animals and humans born as purely theoretical beings who, after forming perceptions and deliberations, suddenly get the idea to execute movements by their own power, thus “discovering” the will.
The author declares this hypothesis not only absurd but contrary to all observation. The vivid account of initially rule-less, will-less movements being perceived, observed, and then used voluntarily is a fantasy. Only the existence of reflex movements is real. We do not know that reflex movements must precede voluntary ones, nor that they are taken into the will’s service. The opposite can often be proven: mechanical practice shows that voluntary movements, even complex ones, gradually become mechanical, eventually becoming reflex-like. We all learned to walk with great effort; swimming, dancing, and piano-playing require new practice. After learning, only the initial directing impulses depend on the will; the rest proceeds mechanically and with greater certainty. Thus, voluntary movements can be shown to become mechanical in many cases, but there is hardly a reliable observation of the reverse.
The hypothesis relied on the fact that newborns show reflexes and irregular automatic movements but not reliably voluntary ones. Humans are born more helpless than any other creature, mainly because the will initially controls bodily organs very imperfectly. However, how the child learns movements contradicts development from reflexes. Practice does not use ready-formed movements but begins with a will-produced but inappropriate action, which through repetition under sensory control reaches its goal. Initially, every act of a composite movement must be will-guided; later, a single impulse suffices for a whole series of actions. This confirms the transition from voluntary to reflex-like movements.
The author asks how the fantasy of the will’s origin from mechanical movements can be maintained against observations of lower animals. A chick just hatched from the egg, still carrying the shell on its back, moves completely purposefully, spared the long practice a human child needs. Here we must assume the will uses an innate mechanism providing purposeful movements. But are these movements purely mechanical, unconscious, and unintended? No observer would claim the will first arises here. Rather, the will is there from the beginning; it is the original motor of movements, with practice intervening to a lesser degree than in human children. The lower we go in the animal series, the simpler the will-acts, the more practice recedes, and the clearer it is that with the appearance of sensation and consciousness, the will is already present.
Observation confirms what the inner connection of psychic functions suggests: the will is not a property arising later in consciousness but is originally bound to consciousness. There is no will without consciousness, just as there is no consciousness without will. Schopenhauer’s attribution of will to a falling stone is called the product of a fantastic metaphysics, using “will” in a sense unrelated to the psychological concept. It is also unjustified to view the empirical will, known as the cause of our own will-acts, as an unconscious force that only becomes conscious in its effects. The will can only be an object of inner experience as a fact of consciousness, like an idea or feeling. We feel ourselves immediately as self-active, and to this feeling of one’s own activity we attach certain inner and outer changes as its effects. We call this feeling of self-activity “will” and the connected changes “will-acts.” An unconscious will would lack the feeling of self-activity and its relation to changes in our ideas; such a thing may be anything, but it is not what we call our will from immediate inner experience.
The doctrine of the unconscious will arose from a partially justified reaction against the traditional will-theory. The latter considers manifold ideas and experiences as conditions preceding all will-activity, seeing in it only the external realization of a purpose-idea previously present in consciousness.
Voluntarism and Intellectualism
The text states that the introduction of the experimental method is the most obvious external feature distinguishing new psychology from old. Under its influence, the concept of the will has become the central problem. The author credits Fr. Paulsen with first using the terms to divide current psychology into “intellectualistic” and “voluntaristic” directions. One must avoid mixing these psychological contrasts with metaphysical views that use the same terms but have different meanings. A person can be a metaphysical voluntarist and a psychological intellectualist, like Schopenhauer. Conversely, one could be a metaphysical intellectualist and a psychological voluntarist, as might be said of Fichte if his metaphysical and psychological ideas could be separated. The author states his own psychological voluntarism has nothing to do with his metaphysical voluntarism: his psychological concept of the will is entirely empirical, derived from analyzing concrete conscious processes, while his metaphysical concept is a boundary concept of a hypothetical character. He does not deny the metaphysical concept can be prepared by the empirical one, but they must be carefully separated. The essay in question deals only with empirical will processes, asking what actually occurs when we will something, whether in external action or internal conscious process. An answer is “voluntaristic” if it does not derive willing simply from sensations, ideas, or intellectual processes. Intellectualistic views include those where the will itself is an idea (e.g., of a movement) or an intellectual act, and also those that insert a transcendent act of will, since that is not an empirical psychological process. For empirical voluntarism, the will process is not an elementary content of consciousness but an affective process composed of feelings, whose distinctive features lie in the connection of its components.
The author cites a positive and a negative motive for his view. The positive one came from reaction experiments reported in an earlier essay. The value of the psychological experiment lies less in measuring time values than in objectively controllable, repeatable self-observation.
The Unfavorable Conditions of Spiritist Observation
Wundt defends his characterization of the conditions under which spiritualist manifestations are observed as “unfavorable.” He defines such unfavorable constellations as those where the observer cannot freely command his senses and instruments, comparing the situation to asking a physicist to observe a magnet’s oscillations through a keyhole, or an astronomer to use a cellar vault as an observatory. The first condition for any successful experiment is that all present must join hands on a table, with no observer permitted outside the circle, which removes much of the operational field from view. Mr. Slade sometimes positions himself so his legs are visible, but only at his own discretion, never at the observers’. The medium determines when and whether a phenomenon occurs; observers may propose experiments, but the medium executes them. When a new proposal is made, the spirits answer “we will try it,” and sometimes it succeeds, sometimes not. Unwanted phenomena interrupt those desired, throwing attention about in ways disruptive to exact observation. Subjective phenomena also distract: Slade points out light appearances on the ceiling that others cannot see, and he falls into sudden convulsions.
The Author’s Own Session with Slade
Wundt notes that saying experiments were made “with or on” Slade is incorrect—Slade made the experiments; if anyone was experimented upon, it was those attending. He reports his own observations. Present were two colleagues, Messrs. Ludwig and Thiersch. They sat around a square card table, one person per side, hands stacked on the tabletop. Several writings appeared on a slate held wholly or partly under the table by Slade. Once a longer writing was obtained between two hinged, folded slates; Slade gradually drew this double slate out from under the table’s edge so it was briefly fully visible, but his hand supporting it remained hidden. Most writings were in English; one in faulty German, as a halting American or Englishman might write. The pocketknife experiment occurred as previously described. Throughout most of the session the room door shook violently, as from wind—but the air was perfectly still that afternoon. Slade repeatedly fell into convulsive twitches and asked the author, seated beside him, whether he felt anything—he did not. Others occasionally felt blows against their legs, and the slate they held under the table was forcibly pushed away; this did not happen to the author. At session’s end, Slade laid his hands on theirs and lifted the table several inches, then let it drop; one could clearly feel the table lifted by a central blow from below. Slade could not comply with their wish to conduct experiments with an observer outside the circle, declaring the spirits would not obey under that condition; he claimed to be a completely passive observer who must submit to conditions he had discovered favorable. Slade told the author he was a medium “of a strong power,” without explaining how he knew this; the author notes he has never experienced phenomena justifying that diagnosis.
Inability to Explain the Experiments
Asked whether he can conjecture how the experiments were produced, Wundt answers no. Such phenomena lie entirely outside his scientific training. A natural scientist can only judge experiments when he has himself experimented in related directions. Were he truly a medium “of a strong power,” he might answer better. What strikes him is that Slade also refuses all explanation. Slade is medium and experimenter and must know the conditions; he claims total ignorance and passivity—but this is obviously false, since phenomena occur only at his sessions and generally in the order he wishes.
Agreement on the Question’s Importance
Wundt agrees with his correspondent that natural science and philosophy are so interested in the reality or non-reality of spiritualist phenomena that one must take a position. The question would be extremely painful if he had to hold all natural explanation impossible.
Comparison to Conjuring
The experiments he witnessed would impress any unbiased reader who has seen skilled prestidigitators as well-executed conjuring tricks. The correspondent seems to lack experience with magicians—understandable for a busy scholar—but should have examined a skilled magician’s performances before judging so decisively. Even spiritualism’s most eager adherents admit these are outwardly closest to spiritualist manifestations. None of Slade’s experiments exceeded a good conjurer’s capacity. Though a magician has advantages (chosen locale, more aids and assistants), Slade has his own: fewer experiments, participants fixed at one table, no program to follow, and failures that do not damage his reputation. Where a “Professor of Magic” uses pomp to distract attention, Slade achieves the same through his subjective accidents.
On More Astonishing Reported Feats
More remarkable feats occurred in the author’s absence. But these were visible only to observers convinced beforehand of the experimenter’s credibility. Such observers naturally omit precautions others deem essential and may leave out incidental circumstances whose knowledge would alter judgment. This is no reproach—their good faith honors them—but it robs their observations of demonstrative force. The author prefers science’s authority to that of some respectable representatives who observed in a field far from their own research.
Hypotheses About Spirit Phenomena
The correspondent discusses three hypotheses: expressions of natural forces; effects of intelligent beings belonging to a four-dimensional space, alternately entering our three-dimensional space and vanishing into the fourth dimension; and manifestations of so-called spirits or ghosts. Wundt prefers “ghosts” since philosophical usage understands “spirit” as bodiless, while spirits occasionally undergo materialization—a property only the German word “Gespenst” unambiguously denotes. The first hypothesis is rightly rejected since phenomena indicate willful acts of intelligent beings. He declines to follow the Kantian epistemological argument but notes no essential difference between the two remaining hypotheses: a ghost is merely a spirit that has become material.
The Persistence of Superstition
Wundt warns against premature triumph over superstition, noting at least two superstitious epidemics in European society during the last century, plus smaller infections. The preceding open letter on Spiritism, written when the spiritist delusion peaked, may become timely again. It stands as an illustrative example for the previous essay on superstition in science and as a cultural-historical document. He hopes future generations will see this dispute as unnecessary effort. The essay is dated May 1885. The last two essays form a whole, arising from the spiritist movement that spread from America to Germany in 1879-80, reaching educated and learned circles. The essay “Aberglaube in der Wissenschaft” was printed in “Unsere Zeit” in 1880 but placed first, with the open letter on Spiritism serving as an exemplification. The letter, titled “Der Spiritismus, eine sogenannte wissenschaftliche Frage,” answered Herr Ulrici’s “Der sogenannte Spiritismus eine wissenschaftliche Frage” in 1879. It was provoked by the Halle philosopher’s appeal to Leipzig scholars who attended demonstrations of the American medium Slade. Wundt refrains from detailing these errors, linked to the sad end of a meritorious colleague. He recalls a biographical note on Slade from his traveling companion, read in “Die Gegenwart”: Slade was originally a “rubber man,” but a stroke prevented this work, so he turned to “mediumism.” This reveals his table-writing tricks as inferior sleight-of-hand: Slade wore shoes without soles and silk stockings, having great toe dexterity. Spiritists tried to recruit Fechner, suspected of occult leanings due to his mystical nature-philosophy, but failed.
Main Arguments
The central argument of the collection is that philosophy must abandon its claim to a special mode of knowledge superior to that of the sciences. Wundt rejects the view, which he attributes to some of his contemporaries, that there are two distinct ways of knowing objects: the ordinary way used by the special sciences and a higher way accessible only to philosophy. He insists that either the first way is false or the second; there is no third. When philosophy and science come into conflict, the dissonance can and must be resolved, and philosophy’s task is precisely to get to the bottom of such contradictions and eliminate them.
This argument is developed through a historical narrative. Wundt shows how philosophy, which once encompassed all knowledge, gradually lost its dominance as the special sciences achieved independence. The attempt of nineteenth-century speculative systems to reconquer philosophy’s ancient position was a failure, leaving philosophy outside the sciences rather than above them. The way forward, Wundt argues, is for philosophy to take the whole extent of scientific experience as its foundation. Only then will it become a “science of sciences” in the true sense, continuing and completing the work begun by special research. The philosopher, coming from psychology and logic and familiar with the general development of research, brings preconditions for examining fundamental questions that the specialist easily misses.
A second major argument concerns the nature of matter and the status of atomic theory. Wundt defends atomism against its critics, both those who would replace it with a continuum theory and those who would abolish the concept of matter entirely in favor of a pure energetics. He argues that the concept of matter is indispensable but remains fundamentally hypothetical. The history of science shows that theories of matter undergo constant changes in their execution, even when their foundations remain stable. The great upheavals of recent physics—the discovery of electrons, X-rays, and radioactivity—have recalled the distinction between hypotheses and facts. The principle of the indestructibility of chemical elements, once considered an absolute axiom, has become a relative though generally useful empirical law.
A third argument concerns the relationship between brain and mind. Wundt rejects both the Cartesian dualism that locates the soul in a specific part of the brain and the materialist reductionism that would eliminate the soul entirely. He also rejects the faculty psychology that assigns each mental capacity to a specific brain region. The brain exhibits a division of labor, but complex mental activities arise from the cooperation of numerous central elements. The localization of a function does not mean that the function resides in a particular area; it means only that the intermediate links for transmitting impulses pass through that area. The gradual restoration of functions after brain injury shows that localization is not absolutely unchangeable and that other parts of the brain can substitute for lost functions.
A fourth argument concerns the possibility of experimental psychology. Wundt maintains that mental processes can be studied experimentally, that consciousness is not beyond the reach of scientific method, and that psychology can provide philosophy with essential foundations. He rejects the view that psychology is merely a branch of physiology, insisting that mental phenomena require their own concepts and methods. At the same time, he rejects the view that psychology is a purely descriptive science, arguing that it must seek causal explanations of mental processes.
Throughout the essays, Wundt argues against what he sees as the two great errors of his time: the speculative excess of philosophers who construct systems without regard for empirical facts, and the naive reductionism of scientists who speculate on philosophical questions without epistemological training. The first error leads to systems that are divorced from reality; the second leads to fantasies that ignore the critical lessons of the history of thought. The remedy in both cases is the same: a philosophy that is continuous with the sciences, and sciences that are self-conscious about their methods and limits.
Key Concepts
The concept of the “science of sciences” (Wissenschaftslehre) is central to Wundt’s conception of philosophy. He takes this term from Fichte but gives it a new meaning. For Wundt, philosophy is not a discipline that derives the content of the sciences from a priori principles; it is rather the discipline that takes the results of all the sciences as its material and seeks to unify them. Philosophy is necessary because the special sciences, left to themselves, produce contradictions and gaps that only a broader perspective can resolve. The philosopher does not possess a special mode of knowledge but brings to the examination of scientific questions a familiarity with psychology and logic and an awareness of the general development of research.
The distinction between hypotheses and facts is another recurring concept. Wundt argues that the theory of matter is especially prone to dogmatic rigidity because hypothetical elements are confused with facts. The history of science shows that hypotheses often persist beyond the time when they have lost their justification because of the architectural coherence of a theory. The great upheavals of recent physics have recalled this distinction, reminding scientists that even the most fundamental concepts—matter, atom, element—are ultimately hypothetical.
The principle of the division of labor, borrowed from biology, is applied by Wundt to the brain. Just as different functions in the body are distributed across different organs, so different mental functions are bound to different cerebral substrates. But this principle must be supplemented by the law of substitution: when one part of the brain is damaged, other parts can take over its functions. This law explains the gradual restoration of functions after brain injury and shows that localization is not absolute.
The concept of “Anschaulichkeit” (intuitive picturability) plays an important role in Wundt’s philosophy of science. He argues that natural phenomena, which belong to intuition, must be derived from assumptions about an intuitive substrate. The attempt of some physicists to renounce intuition entirely, treating mathematical equations as pure symbolism, is self-defeating because perceptions are given in space and time, and processes connecting them can only be conceived in space and time.
The idea of the “immeasurable” as opposed to the “infinite” is developed in the essay on the infinity of the world. Wundt argues that the causal series of the world-process is not infinite for our understanding but merely immeasurable, bounded by an initial and a final point. Similarly, the mass of matter filling space may be infinite or may approach a finite limit, depending on how density decreases with distance. Our knowledge can never reach beyond a starting point of the causal series backward or beyond an endpoint forward; the series is immeasurable, not infinite.
The concept of the “seat of the soul” is subjected to critical examination. Wundt traces the history of attempts to locate the soul in a specific part of the brain, from Descartes’ pineal gland through the various hypotheses of eighteenth-century physiologists to the phrenology of Gall. He argues that these attempts rest on a confusion between the physiological conditions of mental activity and the mental activity itself. The brain is not a collection of organs each housing a distinct faculty; it is a system of interconnected elements whose cooperation produces mental life.
Themes
A persistent theme throughout the essays is the tension between the drive for unity in human thought and the actual diversity of scientific knowledge. Wundt recognizes that the human mind seeks systematic unity, that it cannot rest content with a patchwork of disconnected facts. But he also recognizes that premature unity—the kind imposed by speculative systems that ignore empirical findings—is worse than no unity at all. The history of philosophy since Kant is, in his telling, a series of failed attempts to impose unity from above. The task of the present is to achieve unity from below, by taking the results of the sciences as they are and seeking the connections among them.
A related theme is the danger of what might be called “scientific metaphysics”—the tendency of natural scientists, having achieved success in their own fields, to speculate on the deepest questions without regard for epistemological rigor. Wundt documents this tendency in the energetics of Ostwald, who sought to derive ethical concepts from physical principles, and in the evolutionary metaphysics of Haeckel, who constructed an all-encompassing philosophy from the descent theory. He notes with irony that the most careful and exact researcher in his own field will occasionally speculate on the deepest problems as if critical epistemology did not exist. The welcome aspect of this development is that it brings new blood to philosophy from the fresh spring of the individual sciences; the dangerous aspect is that it ignores the lessons of the history of thought.
The theme of intellectual maturity runs through the essays, particularly in the discussion of the infinity of the world. Wundt contrasts the childish worldview, which fills its narrow world with fantasy but has no urge to go beyond its horizon, with the mature consciousness, which has destroyed this fantasy but seeks compensation in the infinity of space and time. The child who believes he has reached the end of all things at the edge of a park is like the Homeric Greeks who saw the ocean as the boundary of the world. Maturity brings the recognition that experience always has limits but that thinking cannot concede an ultimate boundary.
The relationship between the individual and the whole is another recurring theme. Wundt’s psychology emphasizes that complex mental activities arise from the cooperation of numerous simple elements, just as complex bodily functions arise from the cooperation of numerous organs. There is no central faculty that governs the whole; there is only the organized interaction of parts. This theme has implications beyond psychology, suggesting a general conception of how complex phenomena emerge from the interaction of simpler components.
The theme of limits runs throughout the collection. Wundt is acutely aware of the limits of human knowledge—the limits of observation, the limits of causal inference, the limits of what can be known about the universe as a whole. But he refuses to draw skeptical conclusions from these limits. The fact that we cannot know whether the world is finite or infinite does not mean that the question is meaningless or that knowledge is impossible; it means that we must recognize the hypothetical character of our conclusions and remain open to new evidence.
The Author’s Conclusions
Wundt concludes that philosophy has a necessary and distinctive role to play in the intellectual life of humanity, but that this role must be reconceived. Philosophy is not a higher form of knowledge, accessible only to those who have undergone a special initiation. It is rather the discipline that takes the results of all the sciences as its material and seeks to unify them, to resolve their contradictions, and to clarify their concepts. The philosopher who isolates himself from the sciences becomes irrelevant; the scientist who ignores philosophy becomes naive. The future belongs to those who can combine both perspectives.
On the specific questions treated in the essays, Wundt reaches conclusions that are characteristically balanced and nuanced. The theory of matter, he argues, is indispensable but hypothetical. The atomism of modern physics is supported by a wide range of evidence, from chemical combination to the phenomena of light and electricity, but the concept of the atom remains a construction, not a fact. The discovery of radioactivity has shown that even the chemical elements are not eternal; the principle of their indestructibility is a relative empirical law, not an absolute axiom. The universe is not infinite in the strict sense but immeasurable, bounded in its causal series by an initial and a final point, even if we cannot determine those bounds.
On the relationship between brain and soul, Wundt concludes that the old question of the seat of the soul is obsolete. The brain exhibits a division of labor, with different functions bound to different regions, but complex mental activities arise from the cooperation of numerous elements. The localization of a function does not mean that the function resides in a particular area; it means only that the intermediate links for transmitting impulses pass through that area. The gradual restoration of functions after brain injury shows that the brain is plastic, that other parts can substitute for damaged ones. The soul is not a thing located in a particular place; it is the organized unity of mental life, which depends on the brain but cannot be reduced to it.
Wundt’s conclusions about psychology are programmatic and confident. He believes that experimental psychology is possible, that mental processes can be studied scientifically, and that such study will transform our understanding of mind and its relationship to body. He also believes that psychology is essential to philosophy, that the philosopher who ignores psychology is as deficient as the specialist who ignores neighboring fields. The future of philosophy depends on its willingness to embrace the empirical study of mind.
The final impression left by the essays is of a thinker who is deeply committed to the ideal of unified knowledge but acutely aware of the difficulties in achieving it. Wundt is neither a dogmatist nor a skeptic; he is a critical empiricist who believes that knowledge advances through the patient accumulation of facts and the careful construction of hypotheses, and that philosophy has an essential role in this process. He is optimistic about the future of science and philosophy, but his optimism is tempered by an awareness of the limits of human knowledge and the constant danger of overreaching.
Significance
The significance of these essays lies in their articulation of a position that has become increasingly relevant as the sciences have continued to advance and specialize. Wundt’s insistence that philosophy must be continuous with the sciences, that it must take their results as its material rather than dictating principles to them, anticipates many later developments in philosophy of science. His critique of scientific metaphysics—of the tendency of scientists to speculate beyond their competence—remains timely in an age of popular science books that draw sweeping philosophical conclusions from physics, biology, and neuroscience.
Wundt’s treatment of the theory of matter is historically significant for its engagement with the revolutionary discoveries of the late nineteenth century. He was writing at a moment when the atomic theory was being transformed by the discovery of electrons and radioactivity, and his attempt to think through the philosophical implications of these discoveries is a model of how philosophy should respond to scientific change. His conclusion that the concept of matter is indispensable but hypothetical, that the principle of the indestructibility of elements is a relative empirical law rather than an absolute axiom, has been borne out by subsequent developments in physics.
The essays on brain and soul are significant for their attempt to navigate between the Scylla of Cartesian dualism and the Charybdis of materialist reductionism. Wundt’s insistence that the brain exhibits a division of labor but that complex mental activities arise from the cooperation of numerous elements, his emphasis on the plasticity of the brain and the law of substitution, anticipates central themes in contemporary neuroscience. His critique of faculty psychology and his rejection of the search for the seat of the soul remain relevant to current debates about localization of function.
The collection is also significant as a document of a crucial moment in the history of psychology. Wundt was the founder of experimental psychology, and these essays show him reflecting on the tasks and methods of the new discipline. His argument that psychology is both a science in its own right and an essential foundation for philosophy, that it must seek causal explanations of mental processes while recognizing the distinctive character of mental phenomena, helped to define the field for subsequent generations.
Finally, the essays are significant for their literary and rhetorical qualities. Wundt writes with clarity, wit, and a gift for vivid illustration. His account of the child who believed he had reached the end of all things at the edge of a park, his comparison of the Hegelian system to a floating raft built from the trees of a primeval forest, his ironic observation that the most careful researcher will speculate on the deepest problems as if critical epistemology did not exist—these passages reveal a writer who is not only a scientist and philosopher but also a humanist with a deep understanding of the foibles and aspirations of the human mind. The essays deserve to be read not only for their historical interest but for the continuing relevance of their arguments and the enduring pleasure of their prose.
