A New System of Logic and Method for Interpreting Nature and Reclaiming Human Dominion Over the Natural World
Preface — The Author’s Declaration of Purpose and the State of Human Knowledge
We begin with Bacon’s own preface, where he addresses the reader directly to establish the crisis that his work intends to resolve. This section functions as both an announcement of the book’s revolutionary ambition and a diagnosis of the current condition of learning.
Bacon opens by stating that the state of knowledge is deplorable. He writes that there exists no sound or solid knowledge among humans, and that the entire fabric of learning as it has been handed down from antiquity is a system of “idle fictions” and “empty disputations.” He declares that the sciences have stood still for centuries, making no genuine progress toward the relief of the human condition. What passes for discovery, he argues, is merely the recombination of existing errors. He then poses a stark question: why should humanity accept a method that has produced no fruit? The answer he provides is that the existing logic — the Organon of Aristotle — is entirely inadequate. “The logic now in use,” Bacon states, “serves rather to fix and give stability to errors, which have their foundation in vulgar notions, than to help the search after truth.” The old logic is a tool for defending doctrines, not for discovering new truths.
Bacon then presents his alternative. He offers what he calls a New Organon — a new instrument of the mind, a new method for interpreting nature itself. This method is meant to replace the syllogistic logic of the schools with a process of induction grounded in careful observation and experiment. He makes a distinction that will be central to the entire work: the difference between anticipations of nature (hasty generalizations based on common experience and prejudice) and interpretations of nature (conclusions drawn methodically from properly collected and ordered data). Most human reasoning, he argues, has been mere anticipation. The New Organon aims to teach interpretation.
“Neither the naked hand nor the understanding left to itself can effect much. It is by instruments and helps that the work is done, which are as much wanted for the understanding as for the hand.”
What this preface accomplishes is the clearing of ground. Bacon is not merely proposing improvements to an existing system; he is announcing that the entire edifice of received knowledge must be torn down and rebuilt from its foundations. The reader is thus warned that what follows will not be a gentle correction of Aristotle but a radical replacement of the entire method by which humans have sought truth. The preface establishes the stakes: the recovery of humanity’s rightful dominion over nature, which was lost at the Fall and can only be restored through a true understanding of nature’s laws.
Aphorisms Book I: Section 1-37 — The Idols of the Mind and the Diagnosis of Error
We now enter the first book of aphorisms, where Bacon systematically diagnoses the sources of human error. Book I is preparatory: its purpose is to clear the mind of false notions before the new method is introduced in Book II. Aphorisms 1-37 lay out the general condition of human understanding and introduce the famous doctrine of the Idols.
Bacon begins with the grand proclamation that “Man, as the minister and interpreter of nature, does and understands as much as his observations on the order of nature permit him, and neither knows nor is capable of more.” With this, he establishes the foundational principle: knowledge is power. To command nature, one must first obey her — that is, learn her laws through observation. He immediately follows with the bleak assessment that both the senses and the understanding are weak and prone to error. The senses are dull, easily deceived, and limited in range. The understanding is even worse: it is “like a false mirror, which, receiving rays irregularly, distorts and discolours the nature of things by mingling its own nature with it.”
Bacon then identifies the root cause of the stagnation of the sciences. It is not a lack of talent or effort, but a lack of method. He compares the current state of learning to a ship without a compass: men sail in circles, thinking they are making progress when they are merely retracing old routes. The immense authority given to a few thinkers — especially Aristotle — has had a paralyzing effect. “The wisdom of the ancients” is treated as infallible, but Bacon insists that antiquity properly understood is not the old age of the world but its youth, when humans had little experience. True antiquity is the present age, which has accumulated more time and more experience.
“The human understanding is no dry light, but receives an infusion from the will and affections; whence proceed sciences which may be called ‘sciences as one would.’ For what a man had rather were true, that he more readily believes.”
Here Bacon introduces his most penetrating psychological insight: wishful thinking corrupts knowledge. Humans believe what they want to be true, reject difficult evidence, and cling to comfortable doctrines. The cure for this is not more willpower but a method that forces the understanding to confront nature as it actually is, not as the mind wishes it to be.
The first major conceptual apparatus appears: the Idols of the Mind. These are false notions that “block the entrance” to truth. Bacon identifies four kinds. Idols of the Tribe arise from human nature itself — the tendency of the human mind to perceive more order than exists, to generalize from too few instances, and to be swayed by the most striking or recent examples. Idols of the Cave are the private biases of each individual — a person’s particular education, habits, temperament, and accidental circumstances that distort their vision. Bacon says each person has their own “cave or den” that refracts the light of nature differently. Idols of the Marketplace arise from language and communication — words are imposed upon the understanding by the crowd, and poorly defined or empty terms cause endless confusion. “Words plainly force and overrule the understanding,” Bacon warns, “and throw all into confusion and lead men away into numberless empty controversies and fictions.” Finally, Idols of the Theatre are the false systems of philosophy that have been invented and staged like plays — these are the received dogmas of the schools, the traditions of the ancients, and the misguided systems of thinkers who have built their theories on too little evidence.
What Bacon accomplishes in these opening aphorisms is a comprehensive demolition of intellectual authority. No source of error is left unexamined: the species, the individual, language, and tradition are all shown to be corrupting influences. The reader is left with the unsettling realization that almost every belief they hold is likely distorted. But this is not nihilism — it is preparation. Only by understanding the sources of error can one begin to avoid them.
Aphorisms Book I: Section 38-68 — The Causes of Scientific Stagnation and the False Methods of Inquiry
We move now to the middle of Book I, where Bacon turns from the general diagnosis of error to a specific historical and methodological analysis of why the sciences have failed to advance. Aphorisms 38-68 examine the obstacles to genuine progress and critique the dominant approaches to philosophy that have held humanity back.
Bacon begins by asserting that the true end of knowledge is not pleasure, vanity, or contention, but “the discovery of the forms of things” and “the relief of man’s estate.” Knowledge must bear fruit — it must produce works that improve the human condition. He then identifies the three great vanities that have corrupted learning: the contentious (those who argue for victory rather than truth), the delicate (those who seek knowledge for pleasure and ornament), and the mercenary (those who use knowledge for profit and reputation). None of these pursue knowledge for its proper end, which is power over nature.
Bacon then delivers a devastating critique of the three dominant philosophical schools. The Sophists (by which he means the scholastic tradition descending from Aristotle) have reduced philosophy to “a sort of science of disputation, busy with words but barren of works.” They spin intricate webs of logic that have no connection to the natural world. The Empiricists (like the alchemists and certain physicians) are the opposite problem: they collect a few experiments and then leap to vast generalizations, building “a kind of spider’s web” from too slender a thread. The Superstitious (those who mix philosophy with theology) are the worst of all, because they corrupt both domains. Bacon singles out Plato as having “defiled philosophy with theology” and warns that “the mixture of the divine and the human” produces a philosophy that is “fanciful and superstitious.”
“The discoveries which have been hitherto made in the sciences are such as lie close to vulgar notions, scarcely beneath the surface. In order to penetrate into the inner and further recesses of nature, it is necessary that both notions and axioms be derived from things by a more sure and guarded way.”
The key problem, Bacon argues, is that all previous methods have relied on the syllogism — a form of reasoning that moves from general premises to particular conclusions. But the syllogism is useless for discovering new truths because it assumes the very premises that need to be proved. If the general premises are false or inadequate, the entire chain of reasoning collapses. Bacon proposes instead that philosophy must begin with “a gradual and continuous ascent” from particular observations to middle axioms, and only then to the most general axioms. This is true induction, and it is the only path to certainty.
Bacon then delivers a powerful historical argument. The sciences have remained stationary because men have lacked the courage and method to challenge received authority. “The sciences,” he writes, “are not as yet grown to their full stature; but are as it were the dwarf children of the human understanding.” He compares the current state of learning to the early days of navigation: men hugged the coast of received opinion and never ventured into the open sea of nature. The discovery of the New World was made possible by a new instrument — the compass. Similarly, the discovery of nature’s secrets requires a new instrument of the mind: the New Organon itself.
What emerges from these aphorisms is a clear methodological prescription. The anticipations of nature (hasty and premature theories) must be abandoned. The interpretation of nature (disciplined, methodical induction) must be adopted. Bacon is not merely criticizing the past; he is laying the foundation for a new practice of science, one that will be systematic, collective, and cumulative.
Aphorisms Book I: Section 69-92 — The Idols in Detail and the Preparation for the New Method
We now reach the climax of Book I, where Bacon provides his most detailed exposition of the Idols and begins to clear the way for the positive method of Book II. Aphorisms 69-92 deepen the analysis of each Idol and offer practical remedies.
Bacon begins by reiterating that the four Idols must be “renounced and renounced, and the understanding thoroughly freed and cleansed” before the new method can be applied. He devotes the most attention to the Idols of the Tribe, which he considers the most deeply rooted. The human understanding, he explains, is naturally inclined to suppose that there is more order and regularity in things than there actually is. He gives the example of the ancient astronomers who imagined perfect circles in the heavens because the circle seemed the most “perfect” form. The mind imposes its own structures on nature, and then mistakes them for nature’s own structures. This tendency must be corrected by a method that forces the mind to follow nature rather than lead it.
“The human understanding is not composed of a dry and pure light, but receives a tincture from the will and passions, which gives rise to sciences of our own choice and wish.”
The Idols of the Cave are then examined with a more psychological eye. Bacon notes that some minds are born to see differences, others to see similarities; some love antiquity, others novelty; some are captivated by the simplest explanations, others lose themselves in complexity. Each temperament has its characteristic error. The remedy is not to eliminate temperament but to become aware of one’s own biases and to deliberately correct for them through method.
The Idols of the Marketplace receive the sharpest treatment. Bacon distinguishes between two kinds of words: names of things that do not exist (like “fortune” or “prime mover”) and names of things that exist but are confusedly defined (like “moist” or “heavy”). The first kind can be abandoned, but the second is more dangerous because the words are retained while their meanings shift. “Words,” Bacon says, “are imposed according to the apprehension of the vulgar; and the worsted and finest definitions do not fully remedy this evil.” The very language in which science is conducted carries the infection of common prejudice.
The Idols of the Theatre are the easiest to correct, according to Bacon, because they are merely systems of philosophy that can be exposed and replaced. He classifies these into three types: the Sophistical (like Aristotle’s philosophy, which builds systems from a few common notions), the Empirical (like the alchemists, who build from a few narrow experiments), and the Superstitious (like the Pythagoreans and Platonists, who mix philosophy with theology and superstition). The greatest error of all, he says, is to treat philosophy as the handmaid of theology, because this imposes an external authority on the investigation of nature.
These aphorisms prepare the reader for the transition to Book II. The mind has been cleared, the idols have been identified, and the obstacles to true knowledge have been named. The only remaining question is: what is the positive method? Bacon ends Book I by promising that the interpretation of nature will now be set forth, and he warns that this new method will seem difficult and tedious to those accustomed to the lazy ways of anticipation. But the reward is nothing less than the recovery of humanity’s rightful dominion over creation.
Aphorisms Book I: Section 93-115 — The Conditions for the New Beginning and the Exhortation to Labor
We are now in the final portion of Book I, where Bacon shifts from diagnosing error to prescribing the proper disposition and conditions required for the new method to take root.
Bacon begins this section by declaring that the entire project of the New Organon depends on a fundamental reorientation of human ambition. There are, he says, three kinds of ambition: the ambition of those who seek to extend their own power within their nation; the ambition of those who seek to extend the power of their nation over other nations; and the third and noblest kind, the ambition of those who seek to extend the power and dominion of the human race over the universe. “Now the empire of man over things,” he writes, “depends wholly on the arts and sciences. For we cannot command nature except by obeying her.” This sentence contains the kernel of his entire philosophy: command of nature is achieved only through obedience to nature — that is, through discovering and conforming to her laws.
Bacon then addresses the potential objections that will be raised against his work. Some will say that such a radical reform is impossible because human understanding is too weak; others will say it is unnecessary because the ancients already possessed perfect knowledge; still others will say it is dangerous because it will disturb religion and civil order. To all these, Bacon responds that his method does not depend on any special genius or accidental discovery, but on a sure and regular method that levels all intellects. He compares his approach to a compass and ruler in drawing — even an unsteady hand can draw a straight line and perfect circle with these instruments. Similarly, his method will enable even ordinary minds to achieve results that surpass the best efforts of unaided genius.
The most severe obstacle, Bacon acknowledges, is the sheer labor required. The interpretation of nature demands patience, rigor, and the suspension of premature judgment. Here Bacon makes a bold claim: “I am building in the human intellect a true model of the world, such as it actually is, not such as anyone’s own reason would have it to be.” This model can only be built by collecting history — that is, natural histories of all the phenomena of nature — and then subjecting this history to the method of induction. He calls on all learned men to contribute to this great work, but he warns that the work cannot be done by scattered individuals working in isolation; it requires organized cooperation and the systematic collection of data.
The final aphorisms of Book I are an exhortation to hope. Bacon addresses the reader directly: “Do not be deterred by the difficulty of the task. For the difficulty does not lie in the nature of things themselves, but in the human condition — in the idols that have beset the mind, and in the habit of accepting what is already known rather than seeking what is unknown.” He insists that the door to the inner chambers of nature is now open, and that those who enter with humility and method will find treasures beyond anything the ancients imagined. He concludes Book I by comparing his work to that of Christopher Columbus — who gave the world a new world by sailing not on familiar seas but into the unknown.
These aphorisms serve as a bridge between the critical and constructive parts of the work. Bacon has spent over ninety aphorisms tearing down false methods; now he must inspire his readers to undertake the immense labor of building anew. The emphasis on hope is strategic: he understands that the human mind cannot sustain itself on criticism alone, but requires a vision of what is possible. The comparison to exploration and discovery is meant to stir the reader’s imagination and to frame the New Organon not as a dry logical treatise but as a manifesto for a new age of human achievement.
Aphorisms Book II: Section 1-7 — The First Directions Concerning the Interpretation of Nature: The Table of Essence and Presence
We move now from the preparatory and critical work of Book I into the constructive heart of the *New Organon*: Book II, where Bacon begins to lay out his actual method for interpreting nature. Having cleared the ground of idols and false methods, he now presents the first steps toward a true Interpretation of Nature.
Bacon opens Book II by stating his task directly: “The work and aim of human power is to generate and superinduce a new nature or new natures upon a given body.” He immediately distinguishes this from the goal of human knowledge, which is “to discover the form of a given nature, or the true difference, or the nature that brings forth nature, or the source of emanation.” These two aims—power and knowledge—are not separate but two sides of the same coin. To know the form of a nature is to be able to produce it. Bacon then specifies what he means by form: it is that which, when present, guarantees the presence of the nature in question; when absent, guarantees its absence; and which varies only as the nature itself varies. “For a true form is such that it deduces the given nature from some source of being that is inherent in many natures, and is better known than the form itself, as philosophers say.” This is not the abstract, logical form of the scholastics, but a physical, causal structure that can be manipulated.
Having defined his target, Bacon presents the first step of his method: the preparation of a Table of Essence and Presence. The investigator must collect all known instances in which the nature under investigation is present, but the collection must be diverse and wide-ranging, not confined to any one type of instance. For example, if one were investigating the nature of heat, Bacon suggests a provisional list of instances where heat is present: the rays of the sun (especially as concentrated by lenses), lightning, volcanic flames, the flame of any fire, heated solids, warm-blooded animals, horse dung (which generates heat through fermentation), strong spices like pepper and ginger (which burn the tongue), quicklime sprinkled with water, and even friction between bodies (as in the rubbing of sticks to produce fire). “These instances are to be collected as history, not as inquiry or experiment prematurely theorized.” Bacon is explicit that this list must be provisional and open to correction; its purpose is not to provide an explanation but to lay out the phenomena as they appear in experience.
This table is the first of three tables that constitute the Method of Induction proper. The Table of Presence alone cannot yield knowledge, because it does not yet discriminate between essential and accidental features. Its function is to present the matter to the mind in a comprehensive, ordered fashion, so that the intellect can begin to see patterns. Bacon insists that this process must be mechanical and disciplined, not left to the natural leap of the mind: “For the understanding, left to itself, does not and cannot proceed so cautiously and steadily, but rushes on to generalizations and the principles of things, and is wholly carried away by its own nature.” The table is the first discipline imposed on the mind, forcing it to survey the full range of nature before it attempts to explain anything.
Aphorisms Book II: Section 8-11 — The Table of Deviation or Absence in Proximity
Bacon now introduces the second of the three tables: the Table of Deviation, or of Absence in Proximity. This is the negative complement to the first table. The investigator must collect instances where the nature under investigation is *absent*, but only those instances that are most similar to instances where it is present. The purpose is to begin to isolate what is truly essential by seeing what happens when the nature is missing. “For the form of a thing is never present when the thing itself is absent, even though other things may be present; and it is never absent when the thing itself is present, even though other things may be absent.”
Using the example of heat again, Bacon lists instances of non-heat that are close to instances of heat: the rays of the moon and stars (which give light but not perceptible heat), air that is not heated by the sun, cold-blooded animals (fish, insects), the center of the earth (as inferred from the coldness of deep mines), and so on. Most revealingly, he notes that the rays of the sun in summer produce heat but in winter do not, and that the same rays concentrated through a lens produce much greater heat than when diffuse. These negative instances begin to suggest that heat is not simply a property of light or motion, but something more specific that depends on the degree of concentration or the state of the medium.
Bacon is acutely aware of the danger of negative instances: they are infinite, and the human mind tends to ignore them or to treat them too lightly. “But in the establishment of axioms, a much greater weight is to be placed on negative instances than on affirmative ones, because the negative ones are more powerful in excluding and separating.” This is a crucial methodological point: the negative instances are not merely useful but *more important* than the positive ones, because they allow the investigator to rule out what is not essential. The Table of Absence is thus a device for systematic elimination—for cutting away everything that is not the form, leaving only what is necessary and sufficient.
Aphorisms Book II: Section 12-14 — The Table of Degrees or Comparison
The third and final preparatory table is the Table of Degrees, or of Comparison. Bacon now requires the investigator to collect instances in which the nature under investigation is present in varying degrees—more or less intense, greater or smaller. “For the nature of a body, like the form of a thing, seems to be nothing other than a certain proportion and limitation of a nature that is more general, or the reception of that nature in a particular mode.” If the form of heat is to be discovered, the investigator must examine how heat increases and decreases under different conditions.
Bacon provides examples: the heat of animals varies by species, by age, by the state of the body (exercise increases it, sleep decreases it). The heat of fire varies by the type of fuel, the intensity of the flame, and the distance from the body. The heat of the sun varies by latitude, season, time of day, and altitude. Friction produces more heat when the bodies are rough and the motion is rapid. Fermentation produces heat that rises slowly but persists long after fire would have died. “For the form of a thing is its very essence, which is the cause of the thing’s being, and which is to be found only in the thing itself, not in external accidents.” The Table of Degrees is designed to reveal the quantitative relationship between the nature under investigation and the underlying variables that produce it.
Bacon presents these three tables—Presence, Absence, and Degrees—as the necessary foundation for any true induction. They are not themselves conclusions but the raw material for conclusions, arranged in a specific order that prepares the mind for reasoning. “For when the tables are set before the understanding, it begins to work on them, first by exclusion and rejection, and then by affirmation and admission.” The method is thus a two-stage process: first, the collection and arrangement of data; second, the elimination of impossible candidates for the form until only one remains.
Aphorisms Book II: Section 15-18 — The First Vintage: The Process of Exclusion and the First Attempt at the Form
Bacon now moves from preparation to the actual reasoning process, which he calls the First Vintage. This is the first application of the method to the collected data, and it consists of a systematic Exclusion of natures that cannot be the form. “The work of true induction is to reject or exclude all those natures that are not found in any instance where the given nature is present, or are found in any instance where the given nature is absent, or are found to increase when the given nature decreases, or to decrease when the given nature increases.” This is an explicitly negative operation: the investigator must rule out all candidate causes that fail the tests provided by the three tables.
Applying this to heat, Bacon begins to exclude: heat is not the nature of light, because light from the moon is cold. Heat is not a property of all bodies, because many bodies are cold. Heat is not caused by the motion of the whole body, because a hot body can be at rest (like a heated stone). Heat is not caused by the expansion of the body alone, because water expands when it freezes but becomes cold. “For although exclusion is the chief and most necessary part of induction, yet it is not sufficient for the discovery of the form, because the exclusion only clears the way and opens a path to the affirmation.” After the exclusion is performed, what remains is a set of candidates that have not been eliminated—and from these, the investigator must attempt to guess the true form.
Bacon then offers his first provisional form of heat, based on the application of this method: “Heat is a motion, expansive, restrained, and acting in its strife upon the smaller particles of bodies; and this motion, thus modified, is heat.” He emphasizes that this is not a final conclusion but a permission to the understanding—a working hypothesis that must be tested further. The motion of heat is not a motion of the whole body but an inner motion among the corpuscles; it is expansive, seeking to spread outward; but it is also restrained by the surrounding parts of the body, creating a state of tension or strife. This motion, when it encounters the senses, produces the sensation of heat, but the motion itself is the form.
Aphorisms Book II: Section 19-30 — Prerogative Instances: The Privileged Cases That Guide Investigation
Bacon now introduces the concept of Prerogative Instances—specific types of instances that have special power to guide the investigation, to shorten the process of exclusion, or to reveal the form more directly than ordinary instances. These are not exceptions to the method but refinements of it, tools for the experienced investigator. Bacon lists twenty-seven such instances, each with a name and a description of its function.
The first and most important is the Solitary Instance—an instance in which the nature under investigation appears in a subject that otherwise shares nothing in common with other instances where the nature appears, or conversely, an instance in which the nature is absent though everything else is shared. “For solitary instances are most useful in declaring the nature of the thing, because they narrow the way of exclusion and reduce the number of candidates.” For heat, the solitary instance might be the flame of a candle: it is heat that appears in a body that is in constant motion and change, unlike the heat of a stone or of an animal.
Other prerogative instances include the Migratory Instance, where the nature appears to move into a body that previously did not have it (as when water becomes hot); the Manifest Instance, where the nature appears in its most obvious and uncomplicated form (as in the flame of a candle for heat); the Clandestine Instance, where the nature is hidden or unexpected (as in the heat generated by dissolving quicklime in water); the Constitutive Instance, which reveals the structure or composition of the body (as in the dissection of an animal); and the Crucial Instance (or Instance of the Fingerpost), which decisively decides between two competing explanations. “When in the investigation of any nature the understanding is so balanced as to be uncertain which of two or more natures can be assigned as the cause of the nature in question, then the Instance of the Fingerpost shows which of them is the true cause, and which is to be rejected.”
Bacon does not merely list these instances; he insists that they are not optional luxuries but necessary tools for any serious investigation. The investigator who does not use them will wander indefinitely, unable to reach certainty. “For the method of prerogative instances is to be used in the first vintage, and not postponed until after the tables have been formed; for the tables are always to be made first, and then the prerogative instances are to be applied to them.”
Aphorisms Book II: Section 31-35 — Instances of the Lamp and the Road: Aids to the Senses and to Memory
Bacon continues his catalogue of prerogative instances with a group designed to extend the reach of human perception. The Instance of the Lamp (or Doorway Instance) is any device or experiment that makes hidden natures visible, that brings invisible processes before the senses. “For the senses of themselves are weak and erroneous; nor are instruments for sharpening or enlarging the senses of much avail; but all true interpretation of nature is performed by means of apt and appropriate instances and experiments, where the senses judge only of the experiment, and the experiment judges of the nature.”
The Summoning Instance (or Vindicative Instance) is one that forces a hidden nature to appear, as when a magnet is used to reveal the presence of iron ore in the earth. The Road Instance (or Itinerant Instance) is a series of observations that track a nature through its transformations, like following the path of water as it evaporates, condenses, and freezes. The Supplemental Instance fills a gap left by the senses, as when we use a balance to measure weight that we cannot feel directly.
Bacon is remarkably practical and concrete in this section. He describes actual experiments and observations—the behavior of magnets, the distillation of liquids, the fermentation of organic matter—not as theoretical examples but as models of how the method should be applied. “These instances are as it were lamps, giving light to the investigation of nature; and they are to be gathered together with the same diligence as the tables themselves.” The point is that method alone is not enough; the investigator must also have a store of experimental techniques and observational strategies. The method provides the logic; the prerogative instances provide the tactics.
Aphorisms Book II: Section 36-52 — Further Instances: From the Mathematical to the Political
The catalogue of prerogative instances continues with an astonishing range of examples, each illustrating a different logical or epistemological function. The Mathematical Instance (or Instance of the Measure) applies quantity and proportion to natures that are otherwise qualitative, as when the temperature of a body is measured by the expansion of mercury. The Instance of Divorce (or Separation Instance) isolates a nature from its usual companions, as when heat is produced by friction in the absence of flame, or when light is produced by a firefly without perceptible heat.
The Instance of the Door (or Gate Instance) opens a path to a hidden nature by revealing its effects indirectly, as when the existence of air pressure is demonstrated by the behavior of a barometer. The Instance of the Way (or Path Instance) traces the process by which a nature is generated, as when a plant is grown from seed to flower. The Instance of the Alliance shows how two apparently different natures are related, as when heat and light are found to be different effects of the same motion.
Bacon also includes instances that seem almost political or moral in character. The Instance of the Lamina (or Slab Instance) is a complete and well-ordered collection of instances arranged by the investigator to serve as a permanent reference. The Instance of the Oracle (or Dictating Instance) is a single experiment that reveals the form more clearly than a hundred others. “For as in civil business, the character and disposition of a man is best discovered when he is free and at liberty, so in nature, the secrets of things are best discovered when they are put to the torture of new experiments.”
This metaphor of torturing nature—of putting it to the question through experiment—is one of Bacon’s most famous and controversial images. It expresses his conviction that nature does not reveal its secrets to passive observation but must be forced to answer specific questions. The prerogative instances are the instruments of this interrogation, each designed to elicit a particular kind of response from nature. The catalogue serves as a toolkit for the investigator, a set of proven strategies for extracting knowledge from the world through methodical and disciplined experiment.
Aphorisms Book II: Section 35-37 — The Instances of the Rod or Course, and the Instances of the Dose or Quantity
We are now in the latter portion of Book II, where Bacon continues his catalogue of Prerogative Instances, moving through a series of increasingly specialized cases designed to assist the investigator in particular stages of the Interpretation of Nature.
The Instances of the Rod or Course (Instantiae Virgae seu Cursus) are those that guide the investigator in tracing the continuous motion or process of a nature from its beginning to its end. Bacon explains that many natural operations are not instantaneous but unfold over time through a series of intermediate steps. These instances function “like a rod or staff, by which we may direct our steps in the pursuit of nature.” They show the “continuous motion” of a nature as it passes through successive stages, allowing the investigator to see the causal chain that links the initial cause to the final effect. For example, in examining the generation of an animal, the rod-instance would trace the process from conception through embryonic development to birth, noting each transformation along the way. Bacon argues that without such instances, the investigator is likely to miss the crucial intermediate causes and leap directly from the first cause to the final effect, which leads to error. The rod-instance thus disciplines the inquiry by forcing it to follow nature’s actual sequence rather than the mind’s impatient shortcuts.
The Instances of the Dose or Quantity (Instantiae Dosis) are those that measure the power of a nature by varying the quantity of its application. Bacon writes that these instances are valuable because “the smallest difference in quantity often produces the greatest difference in quality.” By observing how a nature behaves when applied in different amounts—small, moderate, or large—the investigator can determine its potency, its limits, and the threshold at which it changes from one kind of effect to another. Bacon uses the example of a medicine: a small dose may stimulate, a moderate dose may cure, and a large dose may kill. The same substance, in different quantities, produces different natures. This principle reveals that many apparent differences in kind are actually differences in degree. The dose-instance thus helps the investigator to quantify the Latent Process and to discover the precise quantitative relationships that govern natural change. It is a tool for transforming vague qualitative observations into precise quantitative knowledge, which is essential for the mastery of nature. Without these instances, the investigator would remain trapped in the imprecision of common experience, unable to distinguish between essential and accidental variations.
Aphorisms Book II: Section 38-44 — Instances of Struggle or of the Hidden War, and Instances of Limit or Boundary
Bacon now introduces a set of instances that reveal the active, competitive character of natural processes—what he calls the Instances of Struggle (Instantiae Pugnae) or the Hidden War (Bellum Occultum). These are cases where two or more natures are in conflict, where one is trying to overcome or suppress another. Bacon states that “in the body of all things there is a hidden war”—a constant struggle between opposing forces, such as heat and cold, moisture and dryness, or life and decay. The investigator can observe this war most clearly in cases where one nature is on the verge of conquering another, as when a fever overcomes the body’s natural heat or when frost kills a plant. These instances are valuable because they reveal the limits and powers of each nature: they show how much force a nature can exert, how much resistance it can overcome, and under what conditions it is defeated. Bacon compares this to observing two armies in battle: one learns far more about their strength and tactics by watching them fight than by seeing them in separate encampments.
The Instances of Limit or Boundary (Instantiae Limitis) are those that mark the extremes or boundaries of a nature—the points beyond which a nature cannot operate or where it transforms into something else. Bacon calls these “the pillars of Hercules of nature,” marking the limits of human knowledge about a given nature. For example, the boundary of heat is the point at which matter begins to burn or transform into flame; the boundary of density is the point at which a substance becomes impenetrable or turns into a new state. These instances are essential because they prevent the investigator from making false generalizations. By knowing where a nature ends, one can define what it is and what it is not. Bacon emphasizes that “the limits of things are often more instructive than the things themselves.” The boundary-instance forces the investigator to confront the finitude of natural powers and to recognize that no nature extends infinitely. This is a crucial corrective to the tendency of the mind—especially when under the influence of the Idols of the Tribe—to assume that patterns observed in one domain apply universally. The boundary-instance provides the check that prevents such overreaching.
Aphorisms Book II: Section 45-52 — Instances of Alliance, of the Crossing of Species, and of the Lesser Kinds of Evidence
In this section, Bacon continues to expand his catalogue of Prerogative Instances, now turning to cases that reveal relationships between different natures and the ways in which species or kinds are connected or separated. The Instances of Alliance (Instantiae Foederis) are those in which two apparently different natures are found to be connected or to share a common root. Bacon gives the example of the relationship between heat and expansion: metals expand when heated, and this connection is so consistent that expansion can be taken as a sign of heat even when the heat itself is not directly observable. These instances “join things that seem separate” and help the investigator to discover the underlying unity of nature beneath the diversity of appearances. The alliance-instance is a tool for recognizing the Latent Schematism—the hidden structure that governs the relationship between different natures. By identifying such alliances, the investigator can begin to see that what appears as many separate natures may in fact be expressions of a single, deeper form.
The Instances of the Crossing of Species (Instantiae Crucis) are among the most famous and important in Bacon’s system. These are the “instances of the cross” that function as decisive experiments—cases that allow the investigator to choose between two or more competing explanations of a phenomenon. Bacon explains that when the understanding is in doubt between two possible causes or forms, a well-chosen crossing-instance will show which one is correct and which is false. He compares this to a signpost at a crossroads: when the traveler cannot decide which path to take, a cross at the junction indicates the right direction. The crossing-instance “places the understanding at a fork in the road” and forces it to make a decision based on the evidence. Bacon offers the example of determining whether the weight of a substance is caused by its quantity of matter or by some other factor: if one can find a substance that is lighter in appearance but heavier in weight, or vice versa, the crossing-instance reveals which factor is actually responsible. This concept would later become central to the scientific method under the name “crucial experiment” or *experimentum crucis*, directly tracing its lineage to Bacon.
The Instances of the Lesser Kinds of Evidence (Instantiae Minus Fideles) are those that provide weaker or less certain knowledge but are still useful in the early stages of investigation. Bacon includes here the Instances of the Lamp (already discussed), the Instances of the Threshold (cases where a nature is just beginning to appear or just about to disappear), and the Instances of the Path (cases that show the order and sequence of operations). These are the “minor prerogatives” that help the investigator when the more powerful instances are not available. Bacon warns that the investigator should not rely on these weaker instances for final conclusions, but should use them as stepping stones to more decisive evidence. He concludes this section by reiterating that the entire catalogue of prerogative instances is not an exhaustive list but a providential aid—a collection of the most useful tools that experience has shown to be effective in the work of interpretation. The investigator is free to discover additional instances as needed, but these provide a solid foundation for beginning the work of Interpretation of Nature.
Aphorisms Book II: Section 52-52 — The Summary of Prerogative Instances and the Conclusion of the Work
We have reached the final aphorism of Book II and of *The New Organon* itself. In this concluding section, Bacon provides a summary of the 27 kinds of Prerogative Instances he has catalogued and offers his final reflections on the state of the work. He acknowledges that he has not completed the Interpretation of Nature but has only laid its foundations—the Tables of Discovery, the First Vintage, and the catalogue of Prerogative Instances. He compares himself to a builder who has prepared the materials and drawn the plans for a great structure but has not yet raised the walls. The actual application of the method to particular subjects—the detailed investigation of heat, cold, light, sound, life, and so on—remains to be done by future generations of investigators. Bacon issues a final exhortation to his readers: “Let men learn the difference between the idols of the human mind and the ideas of the divine mind. The former are nothing but abstractions rooted in nature; the latter are the very signatures of the Creator impressed upon creation.”
Bacon concludes with a remarkable passage that captures the spirit of his entire project. He states that the New Organon is not a finished system but a beginning—a Great Instauration that will require the labor of many minds over many generations to complete. He compares his work to the discovery of a new world: just as the voyages of Columbus opened the Americas to European exploration, so the new method of induction opens the vast continent of nature to human investigation. The true goal of this work is not intellectual satisfaction but practical benefit: “The end of knowledge is not the glory of the disputant but the relief of the human estate.” Bacon envisions a future in which the discoveries of science—based on the patient, methodical interpretation of nature—will alleviate human suffering, extend human life, increase the productivity of the earth, and restore some of the dominion over nature that humanity lost at the Fall. This is the Relief of Man’s Estate—the ultimate purpose of the new philosophy. The work ends not with a conclusion but with an opening: a call to action, a summons to the work of discovery, and a promise that the method laid out in these aphorisms will, if faithfully followed, lead humanity out of the darkness of error and into the light of genuine knowledge of nature.
