The Shorter Logical Investigations is an abridged edition of Edmund Husserl’s foundational two-volume work, Logische Untersuchungen, originally published in German at the turn of the twentieth century. This English edition, translated by J. N. Findlay from the Second German edition, includes a new Preface by Michael Dummett and is edited and abridged with a new Introduction by Dermot Moran. Published by Routledge in London and New York, the volume presents a selection of key sections from Husserl’s larger work, making his groundbreaking contributions to phenomenology and the philosophy of logic accessible to a broader readership. The book is dedicated to Carl Stumpf, reflecting the personal and intellectual debts Husserl acknowledged in developing his philosophical program.
The work itself emerged from a period of intense philosophical development in German-speaking Europe, representing a decisive break with the psychologistic approaches that had dominated logic and epistemology in the late nineteenth century. Husserl had earlier written from a psychologistic standpoint, but by the time of the Logical Investigations he had fundamentally revised his position. The text is characterized by its rigorous argumentation, careful conceptual distinctions, and detailed phenomenological analyses of consciousness, meaning, and knowledge. It is not a systematic exposition of logic in the traditional sense but rather an effort at epistemological clarification—an attempt to understand the nature of logical concepts by tracing their origins in intuition and experience.
The volume includes substantial front matter: a Preface by Michael Dummett situating the work in the history of philosophy, an Introduction by Dermot Moran explaining its significance and reception, a Select bibliography, and a Translator’s Introduction. The main text comprises the “Prolegomena to Pure Logic” and six “Investigations into Phenomenology and the Theory of Knowledge,” followed by an Appendix on external and internal perception, Notes, and an Index. The Prolegomena addresses foundational questions about the nature of logic, while the six Investigations explore expression and meaning, the ideal unity of species, the theory of wholes and parts, independent and non-independent meanings, intentional experiences, and elements of a phenomenological elucidation of knowledge.
Context
The Logical Investigations occupies a pivotal position in the history of philosophy, standing between two major traditions that would define much of twentieth-century philosophical thought. Michael Dummett’s Preface emphasizes that the work was written between Husserl’s earlier psychologistic book, Philosophy of Arithmetic, and his later Ideas. This temporal positioning is significant: it marks the period of Husserl’s transformation from a psychologistically inclined philosopher to the founder of phenomenology as a distinct philosophical method.
The immediate intellectual context includes Husserl’s engagement with Gottlob Frege, whose savage 1894 review of Husserl’s earlier book profoundly influenced him. By 1900, Husserl had changed his attitude toward psychologism, and his arguments in the Prolegomena were overwhelming, coming close to ending psychologism’s influence in German philosophy. Dummett notes that at the time of the Investigations‘ publication, the views of Frege and Husserl were not far apart. Husserl denied that logic is essentially normative, holding that normative disciplines rest on a theoretical science—a view essentially the same as Frege’s. This convergence is historically important because it shows how analytical philosophy and phenomenology, later seen as divergent traditions, shared common roots in the critique of psychologism.
The work also engaged with a broader philosophical inheritance. Husserl drew on Leibniz, Kant, Bolzano, and Lotze in defending logic as a pure theory of science. His disparaging remarks about Hegel and his encomium of Bolzano, as Dummett notes, can correct a false impression of the German philosophical tradition. The Prolegomena specifically refuted the psychologistic interpretation of logic propounded by John Stuart Mill, which Husserl saw as leading to sceptical relativism.
The reception of the second volume had a major impact on philosophers, leading to the development of phenomenology as a movement. Husserl adopted the term ‘phenomenology’ to characterize his new approach, aiming to clarify the nature of logical concepts by tracing their origins in intuition, going back to ‘the things themselves’. The Investigations attracted the attention of students of Theodor Lipps, including Johannes Daubert, and Husserl regarded the work as a ‘break-through’—not an end but a beginning.
Structure of the Book
The book is organized into two main divisions. The first is the “Prolegomena to Pure Logic,” which addresses foundational questions about the nature of logic and its relation to psychology. The second is “Investigations into Phenomenology and the Theory of Knowledge,” containing six distinct Investigations that explore specific phenomenological and epistemological topics.
The Prolegomena includes chapters on logic as a normative discipline, psychologism and its arguments, empiricistic consequences of psychologism, psychologism as a sceptical relativism, the psychologistic prejudices, and the idea of pure logic. This section establishes the critical groundwork for the positive phenomenological investigations that follow, arguing against the reduction of logic to psychology and defending the autonomy of pure logic as a theoretical discipline.
The first Investigation, “Expression and Meaning,” examines the nature of linguistic signs, the distinction between indication and expression, and the concept of meaning. It addresses the essential distinctions between signs that merely indicate and signs that express, the relationship between meaning and object, and the various equivocations that plague talk about meaning.
The second Investigation concerns “The Ideal Unity of the Species and Modern Theories of Abstraction,” examining how general concepts and universal meanings are possible. It critiques nominalistic theories of abstraction and defends the view that universals are ideal unities accessible through a distinctive form of intuition.
The third Investigation, “On the Doctrine of Wholes and Parts,” develops a formal ontology of part-whole relations. It distinguishes independent from non-independent parts, analyzes the concept of foundation, and establishes a priori laws governing the composition of objects.
The fourth Investigation addresses “The Distinction between Independent and Non-independent Meanings and the Idea of Pure Grammar.” It extends the part-whole analysis to the domain of meaning, distinguishing categorematic from syncategorematic expressions and laying the groundwork for a pure theory of meaning-forms.
The fifth Investigation, “On Intentional Experiences and their ‘Contents’,” is the most explicitly phenomenological. It analyzes the structure of conscious acts, introducing the crucial distinction between act-quality and act-matter, and examining the intentionality of consciousness in detail.
The sixth Investigation, “Elements of a Phenomenological Elucidation of Knowledge,” explores the relationship between meaning-intentions and their fulfilment in intuition. It develops a detailed theory of knowledge as the synthesis of intention and fulfilment, introducing concepts such as fullness, intuitive substance, and the ideal of adequation.
Main Arguments
The central argument of the Prolegomena is the refutation of psychologism—the view that logical laws are psychological laws describing how humans actually think. Husserl argues that logical laws are not natural laws but ideal laws governing the relations among meanings and truths. If logical laws were merely causal laws of thought, they could only be stated as probabilities, leading to an extreme probabilism where even the assertion that all knowledge is probable is itself only probable, ad infinitum. This consequence is absurd, so psychologism must be false.
Husserl identifies confusions underlying psychologistic errors: confusing logical laws with the judgements in which they are known, and confusing a law as a term in causation with a law as the rule of causation. This leads to viewing laws as “governing powers” in thought. He rejects the idea that an ideal person whose thinking conforms to logical laws proves these laws are natural laws, using the analogy of a computer: its operations follow mechanical, not arithmetical, laws. There is a “fundamental, essential, never-to-be-bridged gulf between ideal and real laws.”
The argument extends to show that logical laws cannot have psychological content. No logical law implies a matter of fact or the existence of mental states. The Modus Barbara and Modus Ponens are cited as examples of laws with no psychological content. Pure logical laws are “evident and proven” and free from existential content, unlike empirical laws, which are “idealizing fictions with a fundamentum in re.”
Husserl also argues against the claim that logical laws are empirical but not inductive. He distinguishes psychological presuppositions of knowing a law from logical grounds and premisses. All knowledge “begins with experience” but does not “arise” from it. Laws of truth cannot be laws for facts: truths are not temporal facts, and treating laws of truth as real laws leads to absurdities.
The critique of psychologism culminates in the charge that it leads to sceptical relativism. Husserl distinguishes individual relativism (Protagorean) from specific relativism, or anthropologism, which makes the human species the measure of truth. Individual relativism is “bare-faced” scepticism. Specific relativism is refuted by six arguments: the same content cannot be both true and false; beings not bound by logical principles either misunderstand ‘true’ and ‘false’ or use words differently; a species’ constitution is a fact, and only facts derive from facts, not truths; if truth depends on human constitution, its absence would mean no truth, which is absurd; the constitution would be “causa sui” in respect of laws; and relativity of truth entails relativity of cosmic existence, leading to the absurdity that “man evolves from the world and the world from man.”
The positive argument of the work is that logic is a pure theory of science, grounded in the ideal relations among meanings and truths. Pure logic is not a normative discipline in essence, though it can serve normative purposes. It rests on the “sense” or “essence” of concepts like Truth, Proposition, and Object.
In the Investigations, Husserl argues for a phenomenological approach to understanding consciousness and meaning. Phenomenology is not descriptive psychology in the old sense; it excludes empirical, naturalistic apperceptions and positings. It discusses perceptions, judgements, feelings as such—pure instances of pure species. Phenomenology underlies all clarifications in pure logic and is the necessary basis for scientific psychology, as pure mathematics is for natural science.
The theory of intentionality developed in the fifth Investigation argues that consciousness is always directed toward objects. Every act has both a quality (whether it is a judgement, question, wish, etc.) and a matter (what it is about). The matter determines not merely the object meant but the precise way it is meant. Act-quality is an abstract aspect unthinkable apart from matter, and matter is unthinkable apart from some quality. The union of quality and matter constitutes the act’s intentional essence.
The sixth Investigation develops a theory of knowledge as the fulfilment of meaning-intentions. Knowledge involves a synthesis of identification between an intention and its fulfilment in intuition. Fulfilment admits degrees, and ascending series point to an ideal limit—absolute knowledge, adequate self-presentation. The concept of fullness is introduced to capture the intuitive substance of acts, and the ideal of adequation is defined as the maximum of fullness in all its dimensions.
Key Concepts
Psychologism is the view that logical laws are psychological laws, a position Husserl systematically refutes throughout the Prolegomena. The critique of psychologism establishes the autonomy of pure logic and the ideal character of logical laws.
Pure logic is conceived as a theoretical science of ideal meanings and truths, independent of psychology and any empirical science. It is the foundation for normative disciplines and for the theory of science generally.
Intentionality is the fundamental property of consciousness whereby acts are directed toward objects. Every conscious act is “of” or “about” something, and this directedness is essential to the act’s nature.
Act-quality and act-matter are the two fundamental components of intentional acts. Quality determines the type of act (judgement, question, wish, etc.), while matter determines what the act is about and how its object is meant. The union of quality and matter constitutes the act’s intentional essence.
Meaning is understood in multiple senses that Husserl carefully distinguishes. Meaning can be the act of meaning (the intentional essence of an expression), the ideal unity of meaning (the species or universal that multiple acts can share), or the object meant. The equivocations among these senses are a major source of philosophical confusion.
Expression and indication are distinguished in the first Investigation. Expressions are meaningful signs, while indications merely point to something without expressing a meaning. Facial expressions and gestures are indications, not expressions.
Ideal unity of the species refers to the view that universals are ideal objects accessible through a distinctive form of intuition. The second Investigation defends this view against nominalistic theories of abstraction.
Wholes and parts are analyzed in the third Investigation, which distinguishes independent parts (pieces) from non-independent parts (moments). The concept of foundation is introduced to capture the relations of dependence among parts.
Foundation is the relation whereby one content depends on another for its existence. Non-independent contents can only exist as parts of more comprehensive wholes, and their dependence is governed by a priori laws of essence.
Pure grammar is the theory of the a priori forms of meaning, distinguishing sense from nonsense. It is opposed to the pure theory of validity, which presupposes it.
Categorematic and syncategorematic expressions are distinguished in the fourth Investigation. Categorematic expressions have independent meaning, while syncategorematic expressions (like conjunctions and prepositions) only have meaning in combination with other expressions.
Qualitative modification is the transformation of a positing act into a “mere presentation” of the same object with the same matter. This modification cannot be repeated, unlike presentative objectification, which can be iterated indefinitely.
Fulfilment is the synthesis of identification between a meaning-intention and an intuitive act that satisfies it. Knowledge is understood as the fulfilment of intentions, and fulfilment admits of degrees.
Fullness refers to the intuitive substance of an act—the moments of intuitive content that give the act its intuitive character. Fullness has three dimensions: extent or richness, liveliness, and reality-level.
Adequation is the ideal limit of fulfilment, where the presenting content is also the presented content, achieving perfect self-presentation. Adequate perception is the ideal maximum in all three dimensions of fullness.
Sensuous stuff and categorial form are distinguished in the sixth Investigation. Sensuous stuff is what can be fulfilled in perception, while categorial form (connective, relational, formative acts) finds nothing directly in perception but is founded on perceptual acts.
Themes
A recurring theme throughout the work is the opposition between the ideal and the real. Husserl insists on the “fundamental, essential, never-to-be-bridged gulf between ideal and real laws.” This opposition structures the critique of psychologism and grounds the autonomy of pure logic. The theme extends to the distinction between meanings as ideal unities and the acts in which they are grasped, and to the difference between the ideal laws of pure grammar and the empirical regularities of actual languages.
The theme of foundations runs through the entire work. Husserl is concerned with establishing the ultimate grounds of knowledge and logic, tracing concepts back to their origins in intuition. This is expressed in the slogan of going back to ‘the things themselves’. The work is an effort at epistemological clarification, not a systematic exposition of logic, and this foundational concern shapes its method and argumentation.
The relationship between phenomenology and psychology is a persistent theme. Husserl insists that phenomenology is not descriptive psychology in the old sense, though it underlies all clarifications in pure logic and is the necessary basis for scientific psychology. The distinction is subtle and was often misunderstood, as Husserl himself acknowledges in his revisions. The theme reflects the broader question of how the science of consciousness relates to the science of nature.
The theme of language and meaning is central to the Investigations. Husserl analyzes the structure of expressions, the distinction between indication and expression, and the various equivocations in talk about meaning. The grammatical side of logical experiences cannot be ignored, though grammatical analysis can lead meaning-analysis astray. The theme connects to the broader question of how thought is embodied in language and how linguistic forms relate to logical forms.
The theme of abstraction and attention concerns how general concepts are formed and how we grasp universals. Husserl criticizes nominalistic theories that reduce general concepts to mere devices for economizing thought, arguing that without general meanings no assertions at all are possible. The theme connects to questions about the nature of thought and the role of intuition in knowledge.
The theme of wholes and parts extends beyond mereology to questions about the structure of consciousness and the composition of acts. The analysis of part-whole relations provides a formal framework for understanding how complex acts are built from simpler ones, and how different types of acts relate to one another.
The theme of knowledge as fulfilment emphasizes the dynamic character of cognition. Knowledge is not a static possession but an achievement, a synthesis of intention and fulfilment that admits of degrees and points toward an ideal of complete adequation. This theme connects to the broader question of how finite, fallible beings can aspire to absolute knowledge.
The theme of the ego and consciousness appears in the fifth Investigation, where Husserl discusses the pure ego and the structure of intentional experiences. The theme connects to questions about the nature of self-awareness and the unity of consciousness.
The Author’s Conclusions
Husserl concludes that psychologism is definitively refuted and that pure logic must be recognized as an autonomous theoretical discipline. The arguments of the Prolegomena establish that logical laws are ideal laws, not natural laws, and that any attempt to derive them from psychology leads to sceptical relativism and absurdity. The positive conception of pure logic as a theory of science, grounded in the ideal relations among meanings and truths, provides the foundation for normative disciplines and for epistemology.
The phenomenological investigations demonstrate that consciousness is fundamentally intentional—directed toward objects—and that the structure of intentional acts can be analyzed with precision. The distinction between act-quality and act-matter provides the framework for understanding the varieties of conscious experience, while the analysis of meaning reveals the complex relations among acts, meanings, and objects.
Husserl concludes that phenomenology is not descriptive psychology but a distinct discipline that investigates pure essences and ideal structures. It excludes all empirical, naturalistic apperceptions and positings, discussing perceptions, judgements, and feelings as such—pure instances of pure species. Phenomenology underlies all clarifications in pure logic and is the necessary basis for scientific psychology.
The theory of knowledge developed in the sixth Investigation concludes that knowledge is the fulfilment of meaning-intentions in intuition. This fulfilment admits of degrees and points toward an ideal of adequation—absolute knowledge, adequate self-presentation. The analysis of fullness, with its three dimensions of extent, liveliness, and reality-level, provides a framework for understanding the perfection of knowledge.
Husserl acknowledges the limitations and imperfections of his work. He notes that the first Investigation retains a merely preparatory character, that the treatment of occasional meanings is “an act of violence,” and that the distinction between noetic and noematic aspects is not fully developed. He recognizes that the work is a ‘break-through’, not an end but a beginning, and that much remains to be done.
The work concludes with the recognition that the investigations are only indications of a future treatment. A proper pure theory would define all concepts with mathematical exactness and deduce theorems by formal arguments. The systematic investigation of the combinations of acts is hardly begun. The Logical Investigations thus ends not with a sense of completion but with the acknowledgment of an unfinished project, pointing toward future work in phenomenology and the theory of knowledge.
Significance
The Logical Investigations is a work of first importance in the history of philosophy, marking the transition from psychologistic approaches to logic and epistemology to the phenomenological method that would define much of twentieth-century Continental philosophy. Michael Dummett’s Preface emphasizes that Husserl’s arguments in the Prolegomena were overwhelming, coming close to ending psychologism’s influence in German philosophy. The work thus represents a decisive turning point in the history of logic and the philosophy of mind.
The significance of the work lies partly in its relationship to the analytical tradition. Dummett notes that while Frege is the grandfather of analytical philosophy, Husserl is the founder of phenomenology. At the time of the Investigations‘ publication, the two men’s views were not far apart, and analytical philosophers need to study the Logical Investigations to understand how the two philosophical traditions diverged. The work thus illuminates the common roots of two traditions that would later develop in very different directions.
The work’s impact on the development of phenomenology cannot be overstated. The second volume had a major impact on philosophers, leading to the development of phenomenology as a movement. Husserl adopted the term ‘phenomenology’ to characterize his new approach, and the Investigations attracted the attention of students of Theodor Lipps, including Johannes Daubert. The work provided the foundation for Husserl’s later systematic development of phenomenology, including the doctrine of phenomenological reduction.
The Logical Investigations also made lasting contributions to specific philosophical topics. The critique of psychologism established the autonomy of logic as a theoretical discipline. The theory of intentionality provided a framework for understanding consciousness that would influence generations of philosophers. The analysis of wholes and parts contributed to formal ontology. The theory of meaning and fulfilment anticipated later developments in the philosophy of language and the theory of knowledge.
The work’s significance extends to its methodological innovations. Husserl’s insistence on going back to ‘the things themselves’ and his practice of careful phenomenological description established a new model for philosophical inquiry. The method of eidetic intuition—grasping essences through imaginative variation—would become central to the phenomenological tradition.
The Logical Investigations remains essential reading for anyone seeking to understand the development of twentieth-century philosophy. It stands at the crossroads of analytical philosophy and phenomenology, offering insights that remain relevant to contemporary debates in the philosophy of mind, the philosophy of language, and epistemology. The work’s careful distinctions, rigorous arguments, and detailed analyses continue to reward careful study, and its influence can be traced through the major philosophical movements of the past century.
Detailed Section-by-Section Summary
Title Page and Front Matter
The excerpt opens with the front matter of The Shorter Logical Investigations, Edmund Husserl’s work translated by J. N. Findlay from the Second German edition of Logische Untersuchungen. The edition includes a new Preface by Michael Dummett, is edited and abridged with a new Introduction by Dermot Moran, and is published by Routledge. The original German publication by M. Niemeyer, Halle, occurred in 1900 and 1901, with the Second German edition of Vol. I and Vol. II, Part I appearing in 1913. The abridged edition was first published in 2001, and the book is dedicated to Carl Stumpf. The Contents section outlines the structure: a Preface by Dummett, an Introduction by Moran, a Select bibliography, a Translator’s Introduction, Forewords to the First and Second German Editions, and the main text. The main text comprises the “Prolegomena to Pure Logic” and “Investigations into Phenomenology and the Theory of Knowledge,” which contains six Investigations, followed by an Appendix, Notes, and an Index.
Dummett’s Preface and Moran’s Introduction
Michael Dummett’s Preface establishes the Logical Investigations as a work of first importance, written between Husserl’s psychologistic Philosophy of Arithmetic (1891) and Ideas (1913). Husserl had initially criticised Frege’s Foundations of Arithmetic from a psychologistic standpoint, but Frege’s savage 1894 review profoundly influenced him. By 1900, Husserl had changed his attitude, and his arguments in the Prolegomena were overwhelming, effectively ending psychologism’s influence in German philosophy. Dummett notes that Husserl’s disparaging remarks about Hegel and his encomium of Bolzano correct a false impression of the German tradition. While Frege is the grandfather of analytical philosophy, Husserl is the founder of phenomenology, and at the time of publication, their views were not far apart. Husserl denied that logic is essentially normative, holding that normative disciplines rest on a theoretical science—a view essentially the same as Frege’s. Dermot Moran’s Introduction explains that this is a selection of key sections from the two-volume work. The first volume, Prolegomena zur reinen Logik, appeared in July 1900, and the second volume, containing six Investigations, appeared in two parts in 1901. The work was an effort at epistemological clarification, refuting the psychologistic interpretation of logic propounded by John Stuart Mill, which Husserl saw as leading to sceptical relativism. Husserl defended logic as a pure theory of science, drawing on Leibniz, Kant, Bolzano, and Lotze. The second volume had a major impact, leading to the development of phenomenology, a term Husserl adopted to characterise his new approach. His aim was to clarify logical concepts by tracing their origins in intuition, going back to ‘the things themselves’.
Foreword to the Second Edition
In the Foreword to the Second German Edition, Husserl reflects on the revisions made to the work. The hesitant Introduction to the Second Volume, so little true to the essential sense of the Investigations, was radically revised. Husserl felt its defects immediately and objected to his misleading account of phenomenology as descriptive psychology. He clarifies that psychological description performed in inner experience is opposed to phenomenological description, from which all transcendent interpretations of immanent data are excluded. Phenomenology knows nothing of persons or their experiences; it raises no questions, attempts no determinations, and constructs no hypotheses. The reflective clarity achieved in these years, leading to the systematic doctrine of ‘phenomenological reduction’, was used in rewriting this Introduction and the text of all following Investigations. Of the five Investigations in the First Part of the Second Volume, the first, Expression and Meaning, retains its preparatory character, stimulating thought without doing full justice to its problems. Its treatment of occasional meanings is an act of violence, a consequence of the imperfect conception of ‘truth in itself’ in the Prolegomena. A further defect is its lack of regard for the distinction between the ‘noetic’ and the ‘noematic’, which is first fully laid bare in the Ideas. The Second Investigation, concerning The Ideal Unity of the Species, had a completeness that made only detailed amendments desirable. The Third Investigation, On the Doctrine of Wholes and Parts, underwent thorough revision to assist its important results to better operation. The Fourth Investigation, On the Distinction between independent and non-independent Meanings, was similarly amended and enriched. The Fifth Investigation, On intentional Experiences, had to undergo deep-going revision, tackling cardinal problems of phenomenology. Husserl no longer approves of the rejection of the pure ego but left the arguments in shortened form. The revised Sixth Investigation, designed as the Second Part of the Second Volume, is the most important from a phenomenological point of view, and Husserl went along quite freely, adding whole series of new analyses.
Empiricistic Consequences of Psychologism
Chapter 4 of the Prolegomena, “Empiricistic consequences of psychologism,” opens with a discussion of logical laws misconstrued as natural laws. If laws of thought were causal laws, they could only be stated as probabilities, leading to extreme probabilism where even the assertion that all knowledge is probable is itself only probable, ad infinitum. The author identifies confusions underlying psychologistic errors: confusing logical laws with the judgements in which they are known, and confusing a law as a term in causation with a law as the rule of causation. This leads to viewing laws as “governing powers” in thought. The text rejects the idea that an ideal person whose thinking conforms to logical laws proves these laws are natural laws, using the analogy of a computer whose operations follow mechanical, not arithmetical, laws. The passage stresses the “fundamental, essential, never-to-be-bridged gulf between ideal and real laws,” criticising Sigwart and Wundt. §23 addresses a third consequence: that logical laws must be psychological in content. The author asserts this is “palpably false,” as no logical law implies a matter of fact or the existence of mental states. The Modus Barbara and Modus Ponens are cited as examples of laws with no psychological content. The passage distinguishes pure laws from empirical laws, noting that even strict natural laws like gravitation are “idealizing fictions with a fundamentum in re,” not proven as pure laws. In contrast, purely logical laws are “evident and proven” and free from existential content. §24 counters the objection that logical laws are empirical but not inductive, distinguishing psychological presuppositions of knowing a law from logical grounds and premisses. All knowledge “begins with experience” but does not “arise” from it. Treating laws of truth as real laws leads to absurdities, such as a law ascribing “coming and going” to itself.
Psychologism as a Sceptical Relativism
Chapter 7, “Psychologism as a sceptical relativism,” defines the ideal conditions for the possibility of a theory. Subjective (noetic) conditions concern the possibility of knowledge and justification, while objective conditions concern theory as a unity of truths. A theory violating these is “sceptical.” §33 distinguishes this from metaphysical scepticism, which limits knowledge to mental existence and denies “things in themselves.” §34 defines relativism, distinguishing individual relativism (Protagorean: “Man is the measure of all things”) from specific relativism, or anthropologism, which makes the human species the measure of truth. §35 critiques individual relativism as “bare-faced” scepticism, while §36 critiques specific relativism with six arguments: the same content cannot be both true and false; beings not bound by logical principles either misunderstand ‘true’ and ‘false’ or use words differently; a species’ constitution is a fact, and only facts derive from facts, not truths; if truth depends on human constitution, its absence would mean no truth, which is absurd; the constitution would be “causa sui” in respect of laws; and relativity of truth entails relativity of cosmic existence, leading to the absurdity that “man evolves from the world and the world from man.” §37 extends relativism to any doctrine deriving pure logical principles from facts, stating that pure truths of logic are founded in the “sense” or “essence” of concepts like Truth, Proposition, and Object.
Introduction: Difficulties of Phenomenological Analysis
The Introduction to the Investigations, §§3–7, addresses the difficulty of clarifying logic’s basic concepts, stemming from the extraordinary difficulty of strict phenomenological analysis. These difficulties are essentially the same whether analysis aims at pure essences or treats experiences empirically. The source of all such difficulties lies in the unnatural direction of intuition and thought that phenomenological analysis requires. Instead of naively performing acts and positing objects, we must practice “reflection”—making the acts themselves and their immanent meaning-content our objects. This runs counter to deeply ingrained habits, hence the tendency to slip back into straightforwardly objective thinking. A much-discussed difficulty: when we pass from naive acts to reflection, our former acts necessarily undergo change. Further difficulties arise in stating results, as expressions only fit familiar natural objects, while experiences can be referred to only through ambiguous words like “sensation,” “perception,” “presentation.” Communication requires hearers trained in pure description, excluding naturalistic interpretations. §4 concerns the grammatical side of logical experiences. Analytic phenomenology concerns “presentations” primarily—those given expression. Grammatical analysis can lead meaning-analysis astray, though it offers indirect aid. A perfect a priori parallelism between thinking and speaking would make phenomenology of linguistic forms coincide with meaning-analysis, but such parallelism has no foundation in essence. We must go back from vague acts of meaning to clear, articulate ones saturated with exemplary intuition. §5 states the main aims of the following investigations: to clarify the constitutive Ideas of pure logic, starting with the empirical connection between meaning-experiences and expressions. We must clarify the many concepts covered by “presentation,” where psychological, epistemological, and logical are confused. We must probe the double sense in which the same experience has “content”—real and ideal, intentional content. §6 includes additional notes: investigations will often go beyond the narrow phenomenological sphere; we must use all the concepts we are trying to clarify, an irremovable defect, so investigation proceeds in “zig-zag” fashion; and phenomenology is not “
Meaning and Sense: Initial Equivocations
The investigation begins by noting that ‘meaning’ and ‘sense’ are used synonymously, a parallel terminology that is agreeable precisely because the sense of ‘meaning’ itself requires investigation. Our ingrained tendency to treat the two words as interchangeable makes it a dubious step to differentiate them, as G. Frege has proposed, using one for meaning in our sense and the other for the objects expressed. Both terms are exposed to the same equivocations distinguished in connection with ‘expression’. Logical clarity is impaired because the sense or meaning of an expression is often looked upon as the acts intimated by it, its ideal sense, or the objective correlate it expresses. Since fixed terminological landmarks are lacking, the concepts run confusedly into one another.
Fundamental confusions arise from these facts. General and equivocal names are repeatedly lumped together, since both can be predicatively referred to a plurality of objects. Men did not know how to distinguish the multiple senses of equivocal names from the multiple values of general ones. There is also frequent unclearness as to the difference between collective and general names, for where collective meanings are fulfilled, we intuit a plurality of items, and if intention and fulfilment are not kept apart, it may seem that the collective expression has many meanings.
The Most Detrimental Equivocations
The passage then sets forth the most detrimental equivocations in talk concerning meaning or sense, on the one hand, or meaningless or senseless expressions, on the other. A list emerges. First, it is part of the notion of an expression to have a meaning; this differentiates an expression from other signs. A meaningless expression is properly speaking no expression at all. Here belong articulate, word-like sound-patterns such as ‘Abracadabra’, and combinations of genuine expressions to which no unified meaning corresponds, e.g. ‘Green is or’. Second, in meaning, a relation to an object is constituted. To use an expression significantly and to refer expressively to an object are one and the same, whether the object exists, is fictitious, or impossible. But if one gives a rigorous interpretation involving the existence of the object, then an expression has meaning when an object corresponding to it exists, and is meaningless when no such object exists. Meanings are often spoken of as signifying the objects meant, a usage that springs from a confusion with the genuine concept of meaning.
Third, if meaning is identified with the objective correlate, a name like ‘golden mountain’ is meaningless. Men generally distinguish objectlessness from meaninglessness, but tend to use ‘senseless’ of expressions infected with contradiction, e.g. ‘round square’. Sigwart says a self-contradictory formula such as ‘square circle’ expresses no concept we can think, but sets up an insoluble task. Erdmann has similar opinions regarding ‘A square circle is frivolous’. We should have to apply ‘senseless’ to expressions whose absurdity is mediate, like those shown by mathematicians to be objectless a priori, and deny that concepts like regular decahedron are concepts at all. Marty raises the objection that if the words are senseless, how could we understand the question as to whether such things exist, so as to answer it negatively? Even to reject such an existence, we must form a presentation of such contradictory material. If such absurdities are called senseless, this can only mean that they have no rational sense. These objections are clinching, in so far as these thinkers are confusing true meaninglessness with the a priori impossibility of a fulfilling sense. An expression has meaning in this sense if a possible fulfilment corresponds to its intention. This possibility is meant ideally, concerning ideal contents: meaning as an ideal unity, here called ‘intending meaning’, and fulfilling meaning. We apprehend this ideal relation by ideative abstraction based on an act of unified fulfilment.
Fourth, if we ask what an expression means, we recur to cases where its meaning-intention is intuitively fulfilled. The ‘notional presentation’ gains clarity. Since in the unity of fulfilment the act of intention coincides with the fulfilling act, it seems as if the expression first got its meaning here. The tendency arises to treat the fulfilling intuitions as meanings. Since phenomenological differences have not been closely considered, men have come to locate the significance of expressions in accompaniments of intuitive imagery, leading to a total denial of meaning to absurd expressions. The new concept of meaning originates in a confusion of meaning with fulfilling intuition. On this conception, an expression has meaning if and only if its intention is in fact fulfilled. The final refutation of these opposed notions is postponed to the next chapter.
Occasional Expressions and the Ideal Unity of Meaning
Chapter 3, §24, notes that the last chapter dealt with the act of meaning, but a distinction was made between the act of meaning and meaning itself, the ideal unity as against the multiplicity of possible acts. This distinction is clear in countless cases, but expressions whose meaning shifts, especially occasional or vague ones, raise serious problems. To solve these problems by distinguishing between shifting acts of meaning and ideal units of meaning is the theme of the present chapter.
§25 discusses relations of coincidence among the contents of intimation and naming. Expressions may relate to the contemporary mental state of the person using them. They divide into those that also intimate what they name, and those in whose case named and intimated contents fall asunder. Instances of the former are interrogative, optative and imperative sentences; of the latter, statements relating to external things. If someone utters the wish ‘I should like a glass of water’, this indicates the speaker’s wish, which is also the object of the statement. What is intimated and what is named coincide in part, since intimation extends to the judgement expressed. This holds of statements like ‘I imagine that…’, ‘I am of the opinion that…’. A case of total coincidence seems possible in ‘the state of mind intimated by the words I am now uttering’, though the interpretation breaks down.
Generality of Psychological Function vs. Meaning-Form
The passage opens by dismissing causal/psychological questions about general names as irrelevant to phenomenology. What matters is the descriptive content of the isolated experience of meaning something general versus individual. Husserl distinguishes nominalism’s essence from mere “blind associative play of names.” Its real error lies in overlooking the peculiar consciousness exemplified in our living sense of meaning, actual understanding of signs, and correlative acts of fulfilment yielding the “true” Idea of the universal. Husserl does not object in principle to empirical explanation of this consciousness, but denies its interest for pure logic and epistemology. The nominalist errs by denying abstraction as a peculiar consciousness of the universal, claiming only individual intuitions exist.
Three forms are compared: an A, all A, A in general (e.g., “a triangle,” “all triangles,” “the triangle”). For an A, generality belongs to the logical function of the predicate—the logical possibility of propositions. This is a primitive logical form, irreducible, seen a priori as belonging to meanings as Specific Unities, not psychologically contingent acts. For all A’s, generality pertains to the form of the act itself; we expressly mean all A’s, though no single A is directly presented. The idea of a range is not a complex of ideas of members. For the A (in specie), a wholly different universality is at issue—the universality of the Species. The forms differ logically, not merely grammatically. Specific Generality is an essentially new mode of presentation making us aware of Singular Species.
Critique of Nominalism and Attention
Nominalism’s main error lies in ignoring irreducible peculiarities of forms of consciousness; confusing the various concepts of generality; substituting psychological associations for the logically ideal character of predicative possibility; distorting the generality of universal and specific presentations. Husserl questions whether concentrated attention to an attributive moment equals intuitive grasp of the Species. If we attend to an individual trait (peculiar colouring, noble form) we need not have a general presentation. The proper name “Hans” cannot implicitly name individuating determinations (time, place), or its meaning would change with every step. Individuating determinations marginally noticed are not really meant. Mill’s talk of “unconsciousness” of determinations is an “absurd fiction.” Example: looking at jasmine and saying “Jasmine has a heady scent.”
The theory fails to clarify what gives “attention” its unitary sense. It rests on the Lockean prejudice that objects of consciousness must be mental contents really included in consciousness. But when we judge about a horse, it is a horse, not our sensations, that is presented. The theory cannot account for abstract ideas of attributes never adequately perceived (three-dimensional shapes like sphere, cube) nor non-sensuous concepts (series, identity, being). Attention ranges beyond intuition to thinking itself—we attend to the culture of the Renaissance, elliptical functions, universal states of affairs. Words like “all,” “any,” “if,” “not” cannot be pointed to in sensuous intuition. Objects are not in consciousness “as in a box”; they are constituted in varying forms of objective intention. Defining presentation as mere experiencing of content is “one of the worst conceptual distortions known to philosophy.”
Abstraction and Representation
The medieval nominalist error treats general concepts as mere devices for economizing thought. Locke’s “bundles” passage is quoted. Husserl calls this nonsensical: without general meanings, no assertions at all are possible, not even singular ones. Intuition alone reveals no laws. Even God’s universal intuition would not think. The goal of knowledge is adequate, categorially formed intuitions; “economy of thought” is really “economy of knowledge.”
On the Theory of Wholes and Parts
The abstract/concrete distinction equals Stumpf’s dependent/non-independent contents, extending beyond psychology to objects as such, belonging to the pure a priori theory of objects (formal ontology). Objects relate as Wholes to Parts. Every object is actually or possibly a part. Objects divide into simple and complex. “Complex” may mean having parts, or being cut up into disjoined parts. Colour and determinate redness are not disjoined; redness and extension are. Disjoined parts may be “members” or “pieces” depending on relative independence. “Part” is taken in the widest sense—anything distinguishable “in” an object. Every non-relative real predicate points to a part. Ordinary discourse restricts “part” to independent parts (“pieces”).
The Iterative Structure of Presentative Objectification
The analysis begins by clarifying a fundamental distinction: every object, whether a house, a presentation, or a judgement, corresponds to a presentation of that object. However, the presentation of a judgement is not the same as the presentation of the state of affairs judged; each presents a different object. This leads to a crucial separation between two operations. Qualitative modification, which changes the quality of an act (e.g., from belief to mere presentation), is fundamentally different from producing a presentation “of” that act. Presentative objectification, symbolized as O, P(O), P(P(O)), and so on, can be iterated indefinitely, applying to all objects, whereas qualitative modification cannot be repeated and only applies to acts. A positing act of belief has a “mere presentation” as its counterpart, presenting the same object through the same matter but leaving its existence in suspense. This modification is a one-way street; once belief transforms into mere presentation, one can only return to belief, not modify the modification itself.
The Phenomenology of Iteration and Its Misunderstandings
The iteration of presentative objectification is a phenomenological certainty, evident in acts relating to the ego, such as perceiving something, then presenting to oneself that one is perceiving it, and so on. This is also seen in a painting that depicts a second painting, which depicts a third. These differences are immanently apprehended. Those who consider presentations of presentations to be fictions are confusing the two operations, substituting the impossible qualitative modification with a presentation of a mere presentation. Furthermore, the mere presentation of an act is not a counterpart to that act itself, but to any positing act directed upon that act. For instance, the mere presentation of a wish is the counterpart of a percept directed upon that wish, not of the wish itself.
Redefining “Affirmation” and “Imagination”
The text then discusses the terminology of calling positing acts “affirmative” and their counterparts “imaginative.” While tradition restricts affirmation to judgements, Husserl extends it to all percepts, recollections, and anticipations. Correspondingly, “imagination” must be extended beyond sensuous imagination to cover all counterparts of affirmations, while excluding conscious fictions. When reading a novel, expressions express non-positing acts—”imaginings”—where judgements lack the character of genuine judgements. The term “imagination” suggests pictorial conception, but not all non-positing acts involve imagining, nor are all positing acts non-imagining. A pictured sensuous object can be posited as existent or merely imagined, and the phenomenal content of a painting remains the same whether we regard its figures as real objects or allow them to influence us aesthetically without positing.
Two Conformative Modifications and the Role of Objectifying Acts
Two modifications are distinguished: qualitative and imaginative. In both, the “matter” remains unchanged, though more than quality can alter. Whether to limit “judgement” to unmodified meanings of statements or apply it to all acts of belief is purely terminological. Husserl concludes that “act of judging” should be confined to the significant intentions behind complete statements and their fulfilments, as calling all positing acts “judgements” obscures the distinction between nominal and propositional acts. Several thinkers have interpreted “presentation” widely to include affirmative acts and judgements. Each intentional experience is either an objectifying act or contains one among its constituents whose total matter is individually the same. Objectifying acts uniquely provide other acts with presented objects, and secondary intentions owe their intentionality to foundation on primary ones. Many secondary acts require affirmations, while others suffice with mere modifications.
The Ambiguities of “Presentation” and Its Content
The passage enumerates the many ambiguities of “presentation”: as act-material or matter; as qualitative modification (“mere presentation”); as nominal act; as objectifying act; as opposed to mere thinking (intuition vs. concept); as imagination opposed to perception; as physical thing-images; as signs or surrogates; as the confusion of perception/imagination with sensations/images; as the confusion of appearance with what appears; as all conscious experiences (Locke’s “ideas,” Hume’s “perceptions”); and as opinion (doxa). Twardowski’s distinction between content and object is deemed insufficient, as “content” can mean meaning as ideal unity, intentional essence, separable contents like sensations and images, or matter versus categorial form.
Foreword to the Second Edition (1921)
In the Foreword to the Second Edition, Husserl explains that he could not produce the radical revision promised in 1913, publishing the old text with improvements only in certain sections. The war years prevented the passionate engagement phenomenology required. He allowed the First Section to be reprinted verbatim but improved the Second Section on Sense and Understanding. He defends against the charge of psychologism, calling it “grotesque,” and criticizes Moritz Schlick’s work.
Identification, Matter, and the Limits of Fulfilment
In identification, “matters” serve as carriers of synthesis without themselves being identified; identification concerns the objects presented by such matters. In the act of identification, matters achieve coincidence. Even where qualities are alike, acts need not become quite alike, since an act is not exhausted by its intentional essence. If knowledge admits degrees of perfection even when matter is constant, matter cannot determine knowledge’s peculiar essence. Fulfilment was equated with knowledge in the narrower sense. Each fulfilment involves more or less complete intuitive illustration: what intention means only inauthentically, fulfilment sets directly before us. This “itself” must not be understood too strictly—not every fulfilment need contain a percept. The synthesis involves inequality in worth: the fulfilling act has superiority over mere intention. Fulfilment admits degrees; ascending series point to an ideal limit—absolute knowledge, adequate self-presentation. Not every identification approaches a knowledge-goal: there can be purposeless infinities of identifications, such as indefinitely many arithmetical expressions for 2, or infinitely many images of one thing. In such sequences, gain and loss balance at every step, though the whole series represents increased fulness relative to any single act. The all-sided representation is achieved piecemeal, “blurred” by analogizing or symbolization, as in a rough drawing progressing to a finished painting. Fulfilment does not require assertive quality; “knowledge” is preferred where belief has been confirmed.
Fulfilment and Intuitive Illustration
Intuitive acts seem preferred, inclining one to call all fulfilment intuitive illustration. The relation between intention and fulfilment underlies the conceptual couple of thought (concept) and corresponding intuition. But “intuition” oriented toward this relation does not coincide with the intuitive act, though it presupposes it. Making a thought clear can be achieved even signitively, but self-evident clearness requires intuition in the sense of intuitive acts—recourse to the “originative source” of concepts.
Fullness and Intuitive Substance
“Fullness” is ambiguous. One can consider moments of intuitive content regarding their existential content alone, or in their interpretation as pictures or perspectivally slanted self-revelations. “Purely intuitive” acts are constituents giving moments objective significance. These constituents impart intuitive character and confer “fulness.” Definitions are introduced: intuitively presentative/representative contents are contents of intuitive acts pointing unambiguously to corresponding object-contents. For imagination, these are analogizing or picturing contents; for perception, strictly presentative or self-presentative contents. Intuitively presentative contents of outer perception define sensation; of external fantasy, sensory phantasms or images. The intuitive substance comprises these contents with their interpretation, ignoring quality; all signitive components are excluded.
Weights of Intuitive and Signitive Substance
In intuitive presentation, each part or property of the object corresponds to a part or moment of the conscious act. A distinction is drawn between purely intuitive substance, which corresponds to properties that “become apparent,” and signitive substance, which corresponds to remaining, subsidiarily given properties. Even what is not presented is subsidiarily meant. This is expressed symbolically as i + s = 1, where the weights of intuitive and signitive content sum to the total object-properties. Limiting cases include i=0, s=1 (purely signitive presentation) and i=1, s=0 (pure intuition). Each total act of intuition is either percept or imagination. Perceptual content comprises strictly presentative contents; imaginative content comprises only analogizing contents. The division of perceptual content into pure perceptual content and supplementary image-content is given as P_i + J_i = 1. If J_i = 0, it is pure perception; if P_i = 0, it is pure imagination. Identifying intuitively presentative content in pure perception with the object itself would be a paralogism, as self-presentation may still be merely perspectival. Both pure perception and pure imagination admit degrees of fulness, which has three dimensions: extent or richness, liveliness, and reality-level. Adequate perception is the ideal maximum in all three.
Fullness and Intentional Matter
“Matter” makes the act present just this object in just this manner. Presentations agreeing in matter mean the object as the same, with exactly the same properties. Two judgements have the same matter if everything holding of the state of affairs in one holds in the other. Husserl hesitated whether to define meaning as matter, but this would place assertion outside meaning. Comparison of meaning-intentions with correlative intuitions showed matter reappearing in intuition, furnishing means for identification. Matter must be defined via unity of total identification; differences of fulness have no relevance to its conception.
The Prototype of Meaning-Fulfilment
The relation between meaning and intuiting is modeled on the “proper” individual meaning corresponding to percepts. Someone who knows Cologne itself possesses the genuine “proper meaning” of the word ‘Cologne’—their contemporary experience corresponds exactly to the future confirming percept. The proper name refers “directly” to the city itself, as it is. For structured expressions, the matter seems similar: seeing white paper and saying “white paper” expresses precisely what one sees. However, such ways of speaking are readily misunderstood. The word ‘white’ coincides in fulfilment with the partial percept of the object’s “white-aspect,”
The Cartesian Path Through Doubt
The investigation begins by taking up the Cartesian method of doubt, which grants a privileged epistemological position to inner perception. The core insight is that one cannot rationally doubt one’s own existence, one’s acts of doubting, presenting, judging, or feeling, as such doubt would be self-evidently absurd. This provides an absolute, unassailable ‘evidence’ for the objects of inner perception. In stark contrast, outer perception lacks this fundamental evidence and is demonstrably deceptive. Consequently, the objects of outer perception may possess only a phenomenal or ‘intentional’ existence, and may not qualify as true perception in the strictest sense. This evident character of inner perception offers a purely descriptive mark, free from metaphysical presuppositions, for distinguishing between fundamental classes of perceptions.
Two Distinct Classes of Phenomena
The phenomena of these perceptions form essentially distinct and incomparable classes. Sensory qualities constitute a descriptively closed class, a Kind in the strict Aristotelian sense, with features that necessarily attach to them, such as the proposition that there is no intuited spatiality without quality. On the other side stand phenomena like presentations, judgements, and wishes, which belong to an entirely different world and are not comparable to sensory qualities. A positive mark characterizes this latter class: the mark of ‘intentional inexistence’. This leads to a working definition: psychic phenomena are the phenomena of inner perception, while physical phenomena are those of outer perception. This provides a metaphysically uncommitted definition that can serve as a foundation for both psychology and natural science.
Limitations and the Brentanian Standpoint
These definitions, however, require limitations. Natural science is not concerned with all physical phenomena, but only with those of sense-perception, establishing laws based on the physical stimulation of sense-organs and seeking to explain the sequence of normal, pure sensations by assuming a world extended in three spatial dimensions. Psychology’s true subject-matter, in turn, consists solely of psychic phenomena in the sense of actual states of consciousness. This entire line of thought represents the standpoint of Brentano. He holds that every psychic phenomenon is itself the content of a consciousness, and that the flux of inner experience is a continuous flux of inner percepts. Inner perception is not a second, independent act but is subsidiarily directed upon itself, which avoids an endless complication of acts and renders the ‘evidence’ and infallibility of inner perception possible. In this, Brentano is in harmony with Locke, who defines consciousness as the perception of what goes on in a man’s own mind.
The Critique of Inner and Outer Perception
Brentano’s theories have aroused opposition, but criticism has not penetrated to the decisive points due to defective phenomenological analysis. According to Brentano, inner perception is distinguished from outer by its evidence and incorrigibility, and by essential differences in the phenomena themselves. However, the author argues that inner and outer perception are of an entirely similar epistemological character. Not every perception of the ego or of a psychic state is evident, as these are often perceived with a bodily location, such as anxiety tightening the throat. All psychic phenomena seen in the natural attitude are perceived transcendently. The pure presentedness of experience presupposes a purely phenomenological attitude.
The Ambiguity of ‘Appearance’ and ‘Perception’
The objection that inner perception is a directly-conscious living-through, not an apperception, is addressed. The author argues that outer perception is also a form of apperception, as a house appears by apperceiving sense-contents. The term ‘appearance’ is ambiguous, carrying three distinct meanings: the concrete intuitive experience, the intuited object as it appears, and the real constituents of appearances, such as presentative sensations. Apparent things are not complexes of sensations but are objects of appearances, with properties analogous to sensations. The thing of perception differs fundamentally from the sensational complex that is lived through. The original concept of appearance is what appears, and all experiences in an ego’s experiential unity are called ‘phenomena’. Phenomenology is the theory of experiences in general, and pure phenomenology is the theory of the essences of ‘pure phenomena’, making no empirical assertions and taking all apperceptions purely as experiences. It is an a priori examination in the sense of Ideation, and the Investigations of this work have been purely phenomenological, speaking only of pure possibilities and necessities of the pure ‘cogito’.
The Intersection of Epistemological Distinctions
The ambiguities of ‘appearance’ and ‘perception’ fill theories with errors. In Brentano’s theory, outer perception is not evident, but this is only true if ‘physical phenomena’ means physical things. When Brentano uses the term for presenting contents, they seem infected with fallibility. If an external object is perceived, presenting sensations are experienced but not perceived. If one takes note of these contents, one perceives them with the same claim to inerrancy as any ‘inner’ perception. There are evident percepts of ‘physical’ contents as well as ‘psychical’. The evidence for the whole psychic phenomenon implies that for each part, but the perception of the part is a new perception. Brentano ignores that he has only done justice to one class of percepts of psychic phenomena. The conceptual pairs of inner/outer and evident/non-evident need not coincide. The first is determined by physical and psychical concepts; the second expresses the opposition between adequate perception and inadequate, supposing perception. In adequate perception, the experienced content is the object; in inadequate, content and object fall asunder. This is the essence of the epistemological difference. One can doubt an inadequate perception, but not an adequate, purely immanent one, as the object truly dwells in it. Only the perception of one’s own actual experiences is indubitable, but not every such percept is evident, as in the case of toothache where the pain appears to bore a sound tooth. If ‘psychic phenomena’ means real constituents of consciousness, and inner percepts are adequate percepts, their scope coincides. However, psychic phenomena in this sense are not the same as Brentano’s, Descartes’s cogitationes, or Locke’s acts of mind, as all sense-contents belong. Non-inner perceptions do not coincide with outer perceptions but with the wider class of transcendent, inadequate perceptions. In psychology, perceptions of psychic phenomena are cases of transcendent apperception, as the perceiver apprehends them as belonging to himself. The distinction between adequate and inadequate perception thus intersects the distinction between inner and outer, revealing a more fundamental epistemological divide.
