The Great Instauration: Rebuilding Human Knowledge from Its Foundations
To the King — Dedication and Call for a New Beginning
In this opening address to King James I, Bacon positions his work within the courtly world of patronage while establishing the radical scope of his undertaking. He is not merely offering a book but proposing a transformation of all learning.
Bacon writes that he is presenting “a work touching the interpretation of nature, wherein I purpose to show that there is a way, both of interpreting nature and of applying the uses thereof, better than that which is in use.” He distinguishes his approach from all previous philosophy, which he says has been “content to take the common opinions of men, or the received traditions of the schools, or the arguments of the ancients” as its foundation. Bacon insists that he does not seek to found a sect or school of thought but rather to establish “a true and lawful marriage between the empirical and the rational faculty” — a union that he believes will produce a new kind of knowledge. He assures the king that this work contains nothing seditious or contrary to religion, but rather strengthens the separation between matters of faith and matters of nature. The spiritual realm, Bacon argues, remains untouched by his method, while the physical world is opened to systematic investigation.
This dedication matters because it establishes Bacon’s central claim: that previous philosophy has been built on sand, and that a complete rebuilding is necessary. He is not adding to existing knowledge but challenging its very method. The dedication also shows Bacon’s careful navigation of religious authority — he will never claim that his new science undermines faith, but only that it addresses a different domain.
The Plan of the Great Instauration — Six Parts
Bacon lays out the entire structure of his projected work, describing six parts that together constitute what he calls the Great Instauration — a restoration or renewal of human understanding. This preface functions as a map for everything that follows.
The first part is to be a survey of the existing sciences, “the division of the sciences,” which Bacon later published as *The Advancement of Learning*. The second part is the New Organon, or “the art of interpreting nature,” which provides the new method of investigation. The third part would be a collection of natural and experimental histories — “phenomena of the universe” — serving as raw material for the new method. The fourth part consists of “examples of the new method” applied to specific cases, to demonstrate how it works in practice. The fifth part contains “provisional rules” or anticipations of knowledge that Bacon himself has used, but which he considers temporary. The sixth and final part would be “the philosophy which is the product of the new method” — the completed system of natural knowledge that Bacon himself could not hope to finish, but whose way he was preparing.
“I am building in the human understanding a true model of the world, such as it is, not such as a man’s own reason would have it to be.”
Bacon’s plan is crucial because it reveals that he saw his work not as a completed system but as a foundation for future generations. The six parts move from diagnosis (what is wrong with current knowledge) through method (how to investigate correctly) to completion (the eventual natural philosophy). By publishing the plan first, Bacon commits himself to a comprehensive program while acknowledging that only he and his immediate associates can hope to carry it through.
Preface — The State of Human Knowledge and the Need for Renewal
Bacon opens his preface with a sweeping diagnosis of the human condition. He declares that “the state of knowledge is not prosperous nor greatly advancing,” and that “there is a vast difference between the idolatry of men’s minds and the ideas of the divine mind.” The first is merely human imagination projected onto nature; the second is the true structure of creation.
Bacon argues that the current sciences have failed because they are “founded on notions too narrow and too general, and not sufficiently grounded in experience.” He describes how philosophers have relied on anticipations of nature — premature generalizations based on limited observation — rather than on interpretations of nature, which proceed carefully from particular facts to general principles. The common logic of the schools, derived from Aristotle, is “not merely useless but actually harmful,” because it fixes errors and gives them the appearance of systematic truth. Bacon insists that the human mind must be “not merely supplied with aids but also furnished with new powers,” and that the old instruments of thought — syllogism, disputation, reliance on ancient authority — must be set aside.
Bacon then presents his most radical proposal: a complete cleansing of the understanding before any new knowledge can be built. He writes that “the entrance into the kingdom of man, founded on the sciences, is not much other than the entrance into the kingdom of heaven, where no one is admitted except in the likeness of a little child.” This means that all preconceptions, all inherited opinions, all systems of philosophy must be abandoned. The investigator must approach nature as if for the first time, without any preconceived framework. Only then can the true induction begin — an induction that does not leap from particulars to the highest generalizations, but rises gradually and cautiously through intermediate stages.
This preface establishes the fundamental problem of the entire work: human knowledge is corrupted at its source. Bacon’s solution is not to add new books to old libraries but to change the way the mind works. The radicalism of this claim — that all previous philosophy is not merely incomplete but fundamentally wrong in method — sets the stage for everything that follows in the *New Organon*.
The Distribution of the Work — Detailed Outline of the Six Parts
Bacon provides a second, more detailed exposition of his six-part plan, this time specifying what each part would contain and how they relate to one another. This section serves as a structuring device for the entire *Instauratio Magna*.
For the first part, Bacon says he has already completed *The Advancement of Learning*, which surveys “what has been done in the sciences” and identifies what remains to be done. The second part is the *New Organon* itself, which teaches “how to use the understanding aright in the investigation of nature.” Bacon emphasizes that this is not a logic of probability or disputation but a logic of discovery — a method for producing certain knowledge. The third part requires the collection of “a natural and experimental history” that is “more comprehensive and more accurate than any yet made.” This history must include not only what nature does spontaneously but also what happens when nature is “forced out of her course” through experiments and arts.
“My intention is to unfold and lay open the paths and ways of the human understanding, and to prepare and strengthen the mind itself — not merely to supply it with materials.”
The fourth part provides “examples of the new method” applied to concrete cases, so that readers can see the process in action. The fifth part contains “things which I have myself discovered, proved, or added — not according to the true rules of interpretation, but by the ordinary use of the understanding” — these are provisional, offered as placeholders until the proper method yields better results. The sixth part is “the philosophy which the new method will ultimately produce” — the completed system of knowledge that Bacon frankly admits he does not expect to see finished in his lifetime. He compares himself to a “bell-ringer who calls others to church” or a “forerunner who prepares the way.”
This detailed outline matters because it shows Bacon’s extraordinary ambition matched with an equally extraordinary humility. He knows he cannot complete the work; he is building a method, not a system. The outline also reveals Bacon’s practical sense: he provides provisional results (part five) so that the method does not seem purely theoretical, and concrete examples (part four) so that readers can see how induction works in practice. The entire structure is designed to make the new method teachable and reproducible.
The Great Renewal — Aphorisms Concerning the Interpretation of Nature and the Kingdom of Man — Book I
This section opens the *New Organon* proper, and Bacon immediately states his revolutionary intention. He writes that “man, as the minister and interpreter of nature, does and understands as much as his observations on the order of nature, either in things or in the mind, permit him; and neither knows nor is capable of more.” This is the first axiom of the new philosophy: human power is precisely limited by human understanding of nature’s actual order.
Bacon then presents his famous doctrine of the Idols — the false notions that beset the human mind and must be recognized and expelled before true knowledge can begin. The Idols of the Tribe are those that belong to human nature itself — the tendency to see more order than exists, to be swayed by what is most striking rather than what is common, to let the will and emotions color the understanding. The Idols of the Cave are the particular biases of each individual — education, reading, authority, the peculiar temperament of each person. The Idols of the Marketplace arise from language and communication — words that are poorly defined or refer to nonexistent things, causing endless confusion. The Idols of the Theatre are the false systems of philosophy that have been invented and accepted as if they were real — the systems of the ancients, the schools, the dogmatic traditions.
Bacon devotes many aphorisms to each class of Idol, showing how they operate and how they corrupt inquiry. He argues that the Idols cannot be merely set aside by an act of will; they must be systematically identified and their effects neutralized through the proper method of induction. The mind, left to itself, will always fall back into idolatry.
“The human understanding is like a false mirror, which, receiving rays irregularly, distorts and discolors the nature of things by mingling its own nature with it.”
This section is the diagnostic heart of the *New Organon*. Before Bacon can present his method, he must show why all previous methods have failed. The Idols explain not only why the ancients were wrong but why even modern investigators, using common sense or traditional logic, will also go astray. The cure is not a better argument but a better instrument — the true induction that Bacon will unfold in Book II.
Book I Continued — Arguments Against Anticipations and the Authority of the Ancients
Bacon continues his critique by attacking two deeply held assumptions: that the ancient philosophers had already discovered the truth, and that the human mind, if left to its natural operations, can arrive at sound conclusions. He devotes a series of aphorisms to demolishing these positions.
Bacon argues that the ancients — particularly Aristotle, Plato, and the other Greeks — were children of philosophy, not its mature exponents. They were brilliant but lacked the two things necessary for real science: a method for interrogating nature and a sufficient body of empirical facts. The Greek philosophers “wasted their strength in verbal disputations” and “scarcely ever had the patience to consult nature herself.” Even when they did observe, they did so without the aid of instruments or systematic experiment. Their systems, however impressive, are anticipations — premature leaps from a few observations to universal principles — rather than interpretations of nature based on patient induction.
Bacon also attacks the reliance on syllogistic logic, which he says is useless for discovering new truths. The syllogism only works with propositions that are already known; it cannot generate new knowledge about nature. “The syllogism consists of propositions, propositions of words, and words are the tokens of notions. If the notions themselves are confused and rashly abstracted from things, there is no solidity in the superstructure.” Since the basic notions of traditional philosophy — “substance,” “quality,” “act,” “power” — are poorly defined and not grounded in careful observation, any argument built from them is unsound.
“There are and can be only two ways of searching into and discovering truth. The one flies from the senses and particulars to the most general axioms, and from these principles, the truth of which it takes for settled and immovable, proceeds to judgment and to the discovery of middle axioms. And this way is now in fashion. The other derives axioms from the senses and particulars, rising by a gradual and unbroken ascent, so that it arrives at the most general axioms last of all. This is the true way, but as yet untried.”
This contrast between the two ways — the way of anticipation (old philosophy) and the way of interpretation (new method) — is the central distinction of the *New Organon*. Bacon is not merely criticizing the past; he is setting the stage for a completely different approach to knowledge. The reader is now prepared for Book II, where Bacon will lay out the actual procedure of true induction.
Book II of The New Organon — Aphorisms on the Interpretation of Nature and the Kingdom of Man
LOCATE: We now enter the second book of the *New Organon*, where Bacon moves from the destructive critique of false methods to the constructive presentation of his own method of true induction.
PRESENT: Bacon opens Book II by stating his purpose directly: “The work and aim of human power is to generate and superinduce a new nature or new natures upon a given body.” The work of human knowledge, correspondingly, is “the discovery of the Form of a given nature, or the true difference, or the nature that engenders the nature, or the source from which it springs.” He immediately clarifies his terminology: Form is not the abstract, metaphysical entity of the Scholastics. Rather, it is the “law” or the “true determination” of the simple nature in question. To know the Form of heat, for example, is to know the condition under which heat is necessarily produced, and therefore to be able to produce it at will.
Bacon then offers a series of preliminary distinctions. He notes that there are two kinds of axioms: the Form of a simple nature (e.g., heat, light, weight) and the process of latent configuration (the hidden structure of compound bodies). He acknowledges that the investigation of Forms is the more fundamental and difficult task, because simple natures are the alphabet of which all compound bodies are composed. “For he who knows the Forms of simple natures,” Bacon writes, “knows the nature of all the substances that are compounded from them, even those that have never been discovered.” This is the ultimate goal: a kind of generative knowledge, where from the known laws of the simple natures one can deduce and construct any possible compound.
The core of Book II is the presentation of the Three Tables of Investigation, the first procedural step of Baconian induction. These are not theoretical speculations but concrete, empirical procedures. The First Table is the Table of Essence and Presence — a collection of all known instances where the nature under investigation (in this case, heat) is present. Bacon lists 27 instances: the rays of the sun, especially in summer and at noon; the rays of the sun reflected and condensed, as between mountains or through burning glasses; fiery meteors; burning lightning; eruptions of flame from the cavities of mountains; flame of every kind; ignited solids; natural warm baths; hot liquids; warm vapors and air; “certain sharp and boiling liquors” like strong wines; the heat of animals, especially internally; confined hay or flowers generating heat; quicklime sprinkled with water; and so on. The list is deliberately heterogeneous and drawn from common experience, not from books.
The Second Table is the Table of Deviation, or of Absence in Proximity — instances where the nature is absent, but in bodies most closely related to those where it is present. For heat, Bacon lists the rays of the moon, stars, and comets (which give no sensible heat); the rays of the sun in the middle region of the air (cold); the rays of the sun on mountain tops (less intense); the reflection of the sun’s rays from red-hot iron vs. from a red-hot stone; flame that is “more languid and less glowing” (spirit of wine); animal heat in insects and fish; heat of lime revived vs. heat of lime slaking; and many others. The purpose is to exclude accidental associations — to see what is consistently present when heat is present and absent when heat is absent.
The Third Table is the Table of Degrees, or the Table of Comparison — instances where the nature under investigation appears in different degrees, increasing or decreasing. For heat, Bacon compares: the intensity of flame compared to ignited solids; the increasing heat of the sun through the day and the year; the increasing heat of bodies through friction; the varying heats of animals in different states (exercise, fever, age); the varying heats of chemical reactions; the weakening of heat with distance from the source. The crucial observation is this: “In all these instances, the nature of heat appears to be motion.” He specifies further: “Heat is a motion, expansive, restrained, and acting in its strife upon the smaller particles of bodies.” And even more precisely: “Heat is a motion of the particles of a body, a motion of expansion and contraction, and one that tends toward the circumference, but with a certain modification — namely, that the body, while expanding, also has a tendency upward.”
CLARIFY: These three tables are Bacon’s replacement for the Aristotelian syllogism and the Scholastic method of disputation. They are not arguments; they are instruments of discovery. The tables force the investigator to survey nature systematically, to note what is common and what is varying, and to exclude irrelevant features. The Form of heat, which emerges from this process, is not a metaphysical essence but a physical law — motion of particles with specific characteristics. Bacon’s point is that once you know this Form, you can produce heat at will by inducing that specific kind of motion, and you can also understand why certain bodies are cold (they lack that motion). The tables are the first step in a process that will culminate in the Prerogative Instances — special cases that give more decisive evidence than ordinary ones.
The Prerogative Instances — First Group: Solitary, Migratory, and Conspicuous Instances
LOCATE: Having established the three tables as the basic procedure, Bacon now introduces the Prerogative Instances — twenty-seven special types of instances that have superior evidentiary power and should be sought out by the investigator.
PRESENT: Bacon begins by explaining the function of prerogative instances: “I do not now proceed to axioms and forms immediately,” he writes, “but I will offer a collection and preparation of instances, such as may give light and assistance to the understanding.” These are not random observations but strategically chosen experiments and observations that help the intellect judge between competing hypotheses. He calls them Prerogative Instances because they are “of special privilege and excellence in the work of interpretation.”
The first such instance is the Solitary Instance (*Instantiae Solitariae*). These are instances that exhibit the nature under investigation in subjects that have nothing else in common with other subjects that also exhibit the nature. For example, if we seek the nature of heat, the solitary instance might be the heat of the sun’s rays and the heat of fire — these two have no common substance or structure, yet both produce heat. This excludes the idea that heat depends on a particular kind of matter. Conversely, Solitary Instances in Absence are subjects that resemble others in everything but the nature — e.g., a diamond resembles crystal but does not produce heat when rubbed. This forces the investigator to look for the precise difference.
The second is the Migratory Instance (*Instantiae Migrantes*). These are instances where the nature under investigation is in the process of being generated or destroyed, moving from absence to presence or vice versa. Bacon writes: “For since the Form of a nature is such that the nature is always present when the Form is present, and always absent when the Form is absent, and increases and decreases with the Form, the best way to discover the Form is to watch the nature in its migration.” For example, if glass is heated and then cooled, one can watch the nature of heat appearing and disappearing in the same body. This eliminates accidental causes tied to the specific body.
The third is the Conspicuous Instance (*Instantiae Ostensivae*). These are instances that show the nature in question in a “high and eminent degree,” freed from obscuring complications. Bacon uses the example of heat in boiling water: the motion of the particles is made visible by the bubbling and expansion. Such instances “point to and show the Form in a striking manner,” making the underlying law perceptible to the senses. They are the most useful for beginners in the work of interpretation.
CLARIFY: These three categories of prerogative instances are the first tools in Bacon’s methodological toolbox. They are designed to overcome the natural weaknesses of human perception and judgment. The solitary instance prevents the mind from leaping to false generalizations based on accidental associations. The migratory instance reveals the nature in flux, showing its dependence on specific conditions. The conspicuous instance makes the hidden process visible, providing a vivid illustration of the Form in action. Together, they begin the process of exclusion and rejection that will eventually isolate the true Form.
The Prerogative Instances — Further Groups: Clans, Secret, and Crucial Instances
LOCATE: Bacon continues his catalog of prerogative instances, moving to more sophisticated and powerful types, including the famous Instance of the Fingerpost (*Instantiae Crucis*), or crucial experiment.
PRESENT: The fourth type is the Clan Instance (*Instantiae Constitutivae*), also called Instances of Alliance or Union. These are instances in which a nature appears in a lower degree or in a different mode, and by observing its variations across related cases, the investigator can deduce what is essential. For example, by comparing the heat of different animals, one can see that heat is connected to motion and friction within the body, and that it increases with activity.
The fifth is the Secret Instance (*Instantiae Clandestinae*), also called Twilight Instances or Instances of the Crepusculum*. These are cases where the nature is present but appears to be absent, hidden by the smallness of scale or the subtlety of the process. Bacon writes: “For we must not cease from the investigation until the properties and qualities found in such bodies as are known are brought to light and exhibited in those that are unknown, and the hidden and latent are made manifest and conspicuous.” Examples include the expansion of air when heated — invisible to the eye but detectable by its effects on a balloon or a sealed vessel. These instances remind the investigator that nature is not exhausted by what the senses can directly perceive.
The sixth and most famous is the Crucial Instance (*Instantiae Crucis*), also called the Instance of the Fingerpost or Decisive Instance. Bacon explains its function in a striking metaphor: “When in any inquiry the understanding is brought to a point where it is uncertain which of two or more natures is the cause of the given nature, the Instance of the Fingerpost shows that one of them is the true and efficient cause, while the others are to be rejected.” The phrase “fingerpost” refers to a signpost at a crossroads — it points the way. Bacon gives a detailed example from the investigation of the nature of the tides. One hypothesis holds that the tides are caused by the moon’s influence; another holds that they are caused by the earth’s rotation. A crucial instance would be to observe whether tides occur in enclosed seas (like the Mediterranean) differently from open oceans, and whether they follow the moon’s motion. If the tides in a closed basin still follow the moon, the rotation hypothesis is weakened. In fact, Bacon argues, the observation of tides in different seas shows that the moon is the primary cause, because the tides follow the moon’s position with a regular delay.
The seventh through ninth instances include the Instance of the Crossroads (a variant of the crucial instance), the Instance of the Paths (which shows the process by which a nature is generated), and the Supplemental Instance (which supplies missing data where direct observation is impossible). Bacon continues listing and explaining these, each with its own specific function in the work of interpretation.
CLARIFY: The crucial instance is Bacon’s most important methodological innovation in Book II. It provides a way to decide between competing theories by designing an experiment or observation that gives contradictory results for different hypotheses. This is the ancestor of the modern controlled experiment. Bacon’s genius is to recognize that not all observations are equal — some are decisive, and the investigator should actively seek them out. The catalog of twenty-seven prerogative instances is Bacon’s attempt to train the mind to recognize these strategic opportunities, transforming natural philosophy from a passive contemplation of nature into an active, methodical interrogation.
The Prerogative Instances — Further Groups: Instances of the Road, of the Course, and of the Supplement
LOCATE: Continuing the exhaustive catalog of Prerogative Instances in Book II of *The New Organon*, Bacon now moves from the decisive Crucial Instances to a set of instances concerned with measuring change, establishing causal sequences, and correcting incomplete data.
PRESENT: The next group is Instances of the Road (*Viae Instances*), which mark the stages of natural motion. Bacon explains that these instances “mark the footsteps of nature in its progress” — they show how a cause operates through time and space, not just that it operates. For example, when considering the generation of an animal, the Instances of the Road would show the embryo passing through distinct forms: first a mass without organs, then with rudimentary organs, then with differentiated ones. The investigator who possesses these instances can trace the Chain of Nature in its actual unfolding. Bacon argues that this is essential because nature does not produce effects all at once but through a series of intermediate steps; without mapping the road, one sees only the beginning and end and mistakes the true cause.
Following these are Instances of the Course (*Curriculi Instances*), which relate to the magnitude and direction of natural motion. These instances show not *that* a thing moves, but *how much* it moves and *in what direction*. Bacon gives the example of a pendulum: the time of its swing, the arc it describes, and the gradual diminution of its motion are Instances of the Course. More broadly, these instances take account of Latent Process — the unseen motions within bodies that produce observable effects. Bacon insists that the investigator must measure these courses with precision, using instruments where possible, because the exact quantity of motion often reveals the nature of the cause. A cause that produces a large effect quickly is different in kind from one that produces the same effect slowly.
Then come Instances of the Supplement (or *Instances of Substitution*), which Bacon introduces with a striking admission: human senses are finite, and many natural processes are too fast, too slow, too small, or too large for direct observation. These instances are “those which supply the deficiencies of the senses” — they function as Proxies for Perception. Bacon catalogs several types: Instances of the Door (which open the senses to new phenomena, such as the telescope revealing Jupiter’s moons), Instances of Citing to the Bar (which compel nature to display hidden properties, as a prism breaks light into colors the naked eye cannot separate), Instances of the Way (which measure distances and magnitudes, like the trigonometry used to estimate celestial distances), and Instances of the Lamp (which illuminate subtle processes, such as the use of fire to reveal the volatility of a substance). Each of these is a method for extending the narrow range of human sensation.
“For the subtlety of nature is far greater than the subtlety of sense, and therefore no one should expect to see the hidden processes of nature laid open without the aid of instruments and methods of supplementation.”
Bacon gives a concrete example: the Expansion of Air under heat. The naked eye cannot see this expansion, but if a man places an empty bladder in the sun, the bladder will swell visibly, and if he then moves it into the shade, the bladder will contract. This is an Instance of the Supplement — it makes the invisible visible by using a material proxy. Bacon stresses that the investigator must be ingenious in devising such substitutes, because “the senses are the gateway to the intellect, but they are a narrow gateway.”
CLARIFY: Bacon is confronting the fundamental limitation of empiricism: that human perception is not comprehensive enough to grasp nature’s full subtlety. His Instances of the Supplement are not a retreat from empiricism but its refinement — he insists that the investigator must actively construct instruments and conditions that extend sensory reach. This is the beginning of experimental science as a *technologically enhanced* observation. Notably, Bacon wrote this before many of the instruments he describes (such as the telescope and microscope) had undergone their full development; he is calling for their creation. The Instances of the Road and the Course further emphasize that Bacon’s science is not static — it tracks processes, not just states. The investigator must become a historian of nature, following the succession of causes.
The Prerogative Instances — Final Groups: Instances of the Rod, of the Batch, of the Dividing, and of the Gate
LOCATE: Bacon concludes his catalog of twenty-seven Prerogative Instances in Book II, moving from the more abstract instances of measurement and supplementation to the practical, judicial, and organizational instances that bring the investigation to a conclusion.
PRESENT: The Instances of the Rod (*Virgae Instances*), or Instances of Direction, are the instruments of judgment. Bacon compares them to a rod or staff which guides the traveler’s step. These instances allow the investigator to move from the collected facts to the Form itself. Specifically, the Rod is used to apply Exclusion — the process of eliminating possible causes that do not fit the observed data. Bacon has already described the Table of Presence, the Table of Absence, and the Table of Degrees; the Instances of the Rod are the logical rules for reading these tables correctly. They include the Exclusive method (removing all attributes that vary when the nature under investigation remains constant) and the Declaratory method (affirming the form that remains when all else is excluded). The Rod is the tool by which the investigator compels nature to confess its structure.
Next come Instances of the Batch (or *Instances of the Bundle*), which Bacon describes as “groups of instances gathered together to produce a single result.” These are not individual observations but *collections* that, when taken together, converge on a single cause. The classic example is the case of heat: by gathering all instances of heat (flame, friction, sun, fermentation, animal bodies) and all instances of similar phenomena without heat, the investigator can see what is common across the entire batch. The Batch functions to reduce the multiplicity of nature to a manageable unity. Bacon warns, however, that this must be done carefully — the investigator must not group instances arbitrarily but must use the Tables as his guide.
Then there are Instances of the Dividing (*Divortii Instances*), which separate neighboring phenomena that are easily confused. Bacon uses the analogy of a fork in a river — the dividing instance shows where nature split into two distinct channels. A key example is the difference between Heat and Light. In a candle flame, both exist together, but by using a burning lens that concentrates heat without light, or by examining the light of fireflies that gives almost no heat, the investigator can separate these natures and realize they are distinct forms. The Dividing Instance prevents the investigator from mistakenly attributing all properties to the same cause.
The Instances of the Gate (*Portae Instances*) form the final group. These are the instances that “open the door” to the investigation of a new subject. Bacon states that if a man is entering a new field of inquiry, he should first seek out the Instances of the Gate — the most conspicuous and revealing phenomena that give a “preview” of what the whole field contains. For example, if one wished to investigate the nature of Magnetism, the loadstone itself is the Instance of the Gate: it displays the fundamental behavior of attraction, orientation, and repulsion in a clear and unmistakable form. This initial observation guides all subsequent investigation.
“The Instances of the Gate are those which serve as the entrance and the key to the whole matter; from them the inquirer may first take his bearings.”
Bacon concludes the catalog by noting that these twenty-seven Prerogative Instances are not exhaustive — nature may require new kinds of instances as investigation advances — but they represent the essential methods for beginning a proper Interpretation of Nature. He emphasizes that the investigator should not use them mechanically but with judgment, selecting the most appropriate instance for the question at hand.
CLARIFY: The final groups reveal the full structure of Bacon’s method. The Rod applies logic to the data, the Batch consolidates multiple observations into a single conclusion, the Dividing prevents confusion between distinct phenomena, and the Gate provides an entry point for new investigations. This is not a system of rigid rules but a flexible toolkit — Bacon is training the investigator in *how to think*, not merely in what to do. The catalog as a whole transforms natural philosophy from a passive reception of facts into an active, strategic inquiry, where the investigator selects not just any observation but the *most revealing* one for the question at hand.
Prerogative Instances — Instances of the Rod, of the Course, of the Batch, of the Dividing, and of the Gate
LOCATE: We are in the final portion of Book II of *The New Organon*, where Bacon concludes his catalog of prerogative instances with the most methodologically advanced and practical groups — those that guide the actual conduct of inquiry after the data have been collected and organized.
PRESENT: Bacon introduces Instances of the Rod (Instances Virgae) as those that serve as “a rod or rule for directing the understanding in the trial and examination of any nature.” These are the instances that determine *measurement* — they allow the investigator to assign precise quantitative values to the degrees of a nature. Bacon explains that where simple observation gives only qualitative presence or absence, the Rod gives exact proportion: “By the help of these instances you may judge of the nature as by a rule, and as it were measure it.” He gives the example of the compass of proportion in geometry, where a known ratio can be applied to unknown quantities. In natural philosophy, such instances include the thermometer for heat, the hygrometer for moisture, and other instruments that translate qualities into numbers. Bacon emphasizes that without the Rod, inquiry remains vague and uncertain.
CLARIFY: The Rod is Bacon’s demand for *quantification* in natural philosophy. He is not merely observing that measurement is useful — he is arguing that true knowledge of a nature requires knowing its *degrees*, and that the invention of instruments for precise measurement is itself a crucial part of the method. This anticipates the central role of measurement in modern experimental science.
PRESENT: The Instances of the Course (Instances Cursus) are those that reveal the *succession and motion* of natures — how a nature moves through time and through bodies. Bacon writes that these instances “relate to the course of nature, and show the progress and motion of bodies, and, as it were, the history of the operations of nature.” He divides these into several subtypes: Instances of the Water-bubble, which show the generation and decay of forms; Instances of the Bridge, which connect causal chains across separate observations; and Instances of the Barrier, which show where a natural process stops or is blocked. A key example is the study of the motion of projectiles: “When a stone is thrown, it moves in a curve, not in a straight line, and this curve is compounded of the natural motion of the stone and the impressed motion.” Bacon insists that understanding the *path* of a nature — its trajectory from cause to effect — is essential for controlling it.
CLARIFY: The Course instances address *process* and *change* over time, which static observation cannot capture. Bacon is moving the investigator from seeing nature as a collection of fixed properties to seeing it as a system of motions and transformations. This is the methodological basis for studying dynamics, biology, and any field where sequence matters.
PRESENT: The Instances of the Batch (Instances Sarcinas) are those that “serve to enable the understanding to take in and, as it were, to load itself with many things at once.” These are instances that *condense* multiple observations into a single, manageable fact. Bacon illustrates: “As in the case of the calendar of winds, tides, seasons, and the like, where a single table contains the results of many years’ observation.” The Batch is a tool for *compressing complexity* — it allows the investigator to hold a large body of information in view without losing detail. Bacon notes that this is especially important in the early stages of inquiry, when the number of observations can overwhelm the understanding. The Batch is “the remedy for the confusion and scattered nature of particulars.”
CLARIFY: The Batch is Bacon’s solution to the problem of *information overload*. Before the investigator can apply the inductive method, the data must be organized into a form that the mind can handle. This is the ancestor of data tables, spreadsheets, and systematic catalogs — a practical tool for making large amounts of information usable.
PRESENT: The Instances of the Dividing (Instances Dividuos) are “instances of division and separation, which distinguish nature into its component parts, and reduce the compound to the simple.” This is the *analytical* tool in Bacon’s toolkit. He specifies: “These instances are of great service in separating the various natures which are combined in any body, and in exposing each by itself.” The classic example is the chemical analysis of a compound: by heating, dissolving, or reacting a substance, the investigator may separate its components and study each alone. Bacon also mentions the dissection of animals as a form of Dividing instance. He warns that the division must be “natural” — it must follow the actual joints of nature, not arbitrary categories. “To divide nature otherwise than according to its true structure is to mangle it, not to analyze it.”
CLARIFY: The Dividing instances are Bacon’s method for *reductionism* — breaking complex phenomena into simpler parts. But he insists that the division must respect the real structure of nature, not the preconceptions of the investigator. This is a direct challenge to the scholastic habit of dividing things by logical categories rather than by empirical observation.
PRESENT: The Instances of the Gate (Instances Portae) are the final group — instances that “open the gate, and give the first entrance into the investigation of a nature.” These are the *starting points* for inquiry, the simplest and most accessible facts that point the way to deeper investigation. Bacon explains: “As in a city, the gates are the principal entrances, so in nature, there are certain instances by which the understanding enters most easily into the discovery of forms.” He gives the example of the familiar instances of heat: the fact that heat causes expansion in most bodies, and that intense heat produces light. These are not the deepest truths, but they are the *most accessible* — they give the investigator a foothold. The Gate instances are “the first rays of light” that begin the process of induction.
CLARIFY:** The Gate instances complete the catalog by addressing the *practical beginning* of inquiry. Bacon knows that the investigator cannot simply dive into complex experiments — one must start somewhere. The Gate instances provide that starting point, ensuring that the method is not only rigorous but also *initiable* — something a real human can actually begin to use. This is the final piece of Bacon’s systematic method: from the first simple observation (Gate) through measurement (Rod), process (Course), condensation (Batch), and analysis (Dividing), the investigator has a complete set of tools for the discovery of forms.
