Bacon's Theory of Induction as Presented in the Novum Organum, Part 2 of 2

Book II

Human Power and Human Knowledge

On a given body to generate and superinduce a new nature or new natures, is the work and aim of Human Power. Of a given nature to discover the form, or true specific difference, or nature-engendering nature, or source of emanation (for these are the terms which come nearest to a description of the thing), is the work and aim of Human Knowledge. (Bacon, Novum Organum, Book II, Aphorism 1)

So begins Book II, articulating two of Bacon's central points about humans and the universe as a whole. Bacon's first central point relates human power to the bodies in the world. Nothing really exists except for individual bodies, Bacon reminds us (Book II, Aphorism 2); human power consists in creation—changing and rearranging bodies and letting nature (as the sum of all things acting lawfully) run its course. What Bacon is emphasizing here is that this creation is essentially producing a new nature or feature and adding it to a given body, such as hitting a piece of wood to give it a "flat" nature, or a person physically ingesting water in order to have a "quenched" nature. (Bacon uses "nature" in two senses, one meaning similar to what we mean by it: a lawful universe. The other meaning is synonymous with a property, characteristic, or feature of a given thing.) Producing a new nature and adding it to a given body is the aim of human power, and the transformation of bodies is the subordinate goal that must be accomplished in order to achieve this aim. But without a competent knowledge of the body that will be transformed or altered, no one can give a new nature to a given body, or successfully transfer that nature to a new body. Ignorance is impotence.

What must precede the accomplishment of the aim of human power, then, is the attainment of the aim of human knowledge: to discover the form, or source of emanation, or true difference, of a given nature. And just as human power has a secondary task that must be accomplished in order to carry out its aim, the same point applies to human knowledge: to gain knowledge of the forms, we must discover the causes which led to the form being emanated in things, causes which are in a latent [hidden] process of generation and motion, and we must discover the form which emanates from the latent configuration of bodies while at rest and not in motion. These notions, of form and of the latent processes and configurations of bodies, require much more attention.

The Notion of "Form"

What Bacon precisely means by this word 'Form,' is one of the first questions which must occur to every reader of the Novum Organum, and it is probably one of the last difficulties which will be cleared from his path. (Thomas Fowler, Introduction to Bacon's Novum Organum, edited by Thomas Fowler, second edition, pg. 54)

If the true aim of human knowledge is to discover the "form" of something, then what is this "form"? First, it will be helpful to clarify that it is not a "platonic Form," which is a purely abstract, archetypal "blueprint" on which the phenomena we perceive are modeled after. (In this view, the idea or Form of "Man" is more real than the men we daily deal with, they are simply representations or shadows of this perfect form. See Plato's "Allegory of the Cave" in The Republic for a key discussion of this component of his theory.) Bacon clearly states that only individual bodies exist, which perform certain actions under definite laws—these things and actions aren't modeled after anything else. (Book II, Aphorism 2) He also remarks that forms, as understood as "blueprints" or frameworks, are "figments of the human mind..." (Book I, Aphorism 51)

Next, it will be incredibly beneficial to compare Bacon's "form" with areas of Aristotle's philosophy. It was Aristotle who first held that certain, scientific knowledge is knowledge of causes, it is knowledge of the cause of a fact; Bacon notes that it is a, "correct proposition" that, "true knowledge is knowledge by causes." The important question is: what sort of cause is Bacon referring to?

Bacon accepts Aristotle's division of the idea of "cause" into four types: the efficient, material, formal, and final. The material cause is what the thing in question is made out of, such as a table being composed of wood, a syllable being composed of letters, and a syllogism (a logical argument) being composed of premises. The efficient cause is what happens that brings something about, such as the Earth blocking out the light from the Sun, which brings about the eclipse of the moon; this is how most people understand cause and effect. The formal cause is the pattern or form which makes something the kind of thing it is, e.g. the blocking of light as such is the formal cause of eclipses universally, whether the source of light is the Sun or some other existent. Lastly, the final cause is the end-goal, purpose, or some thing's reason for being, and Aristotle held that it didn't require deliberation, consciousness, or intelligence; in his view, a plant seed had an end-goal of being a fully matured tree, a man had a plan and purpose for building a home, and a sailboat had the purpose of sailing.

While Bacon accepts these four as legitimate, he doesn't believe that they have the same level of importance in advancing the sciences and our knowledge. The final cause corrupts the sciences except for issues which deal with human action. (Many objects in science won't have explicit end-goals or purposes, e.g. the Sun's production of light waves, so an attribution of a final cause may stifle further inquiry.) The material and efficient causes, as people normally investigate them as more remote causes, contribute little to an active science. These two causes lead to limited practical benefits: if you know the cause of a nature, say coldness, only in certain objects, then your knowledge is imperfect, and your power is imperfect if you can only add a given effect to substances that are naturally susceptible to that effect. Knowledge of material and efficient causes may lead to new discoveries, but only with regard to substances or things which are in some respects similar to one another, and you won't reach the deeper boundaries of nature. This is not so with knowledge of the form, of the formal cause:

But whosoever is acquainted with Forms, embraces the unity of nature in substances the most unlike; and is able therefore to detect and bring to light things never yet done, and such as neither the vicissitudes of nature, nor industry in experimenting, nor accident itself, would ever have brought into act, and which would never have occurred to the thought of man. From the discovery of Forms therefore results truth in speculation and freedom in operation. (Book II, Aphorism 2)

The "form" of a nature is its essential qualities or properties, its laws of actions, its source for being what it is. The form is an essential quality, not an accidental feature: if wetness is not always present on a bike, then it is not an essential quality, and therefore is not part of the form of a bike; neither is form derived from another attribute, as if it were an effect from some other cause. The form is one or more attributes which are independent and non-derived, and these attributes compose the essence of the thing, class, or quality. Bacon's view in Book II, Aphorism 4 is that given the form, the nature follows without fail. The form is always present when the nature is present, and implies the nature in all cases, and is constantly inherent in the nature. Likewise, if the form ceases to exist, the nature infallibly vanishes, it is always absent when the nature is absent; in fact, the form's disappearance implies the absence of the nature, and the form inheres in nothing else.

For since the Form of a thing is the very thing itself, and the thing differs from the form no otherwise than as the apparent differs from the real, or the external from the internal, or the thing in reference to man from the thing in reference to the universe; it necessarily follows that no nature can be taken as the true form, unless it always decrease when the nature in question decreases, and in like manner always increase when the nature in question increases. (Book II, Aphorism 13)

This explains Bacon's characterization of "form" as a "nature-engendering nature": the nature must exist whenever the form exists, and cannot exist without it. (For more on this and other matters I discuss in the next few paragraphs, see Thomas Fowler's edition of Bacon's Novum Organum, particularly the section of his introduction called "The Meaning Attached by Bacon to the Word 'Form'.")

Whenever we state the essence in words, we either list the essential qualities, or construct a definition for the word. The important thing we want to gain from the definition is the differentia, or specific difference, as it is often the case that we already know the genus (a general class or category) of the quality, and merely want to discover what distinguishes it from certain other terms that belong to the same genus. To reach a definition of a given nature, in other words a description of its form, one must discover another nature (the differentia) which is convertible with the given nature, but also a narrowing or limitation of a more general nature, which becomes the true genus. To define, say, an “ocean's tide,” you'd have to discover another nature that can be converted to the tide in one's thoughts, the differentia, and is also included under a general nature, say "motion," which then becomes the genus of your definition. In this way, we know what Bacon means by calling the form a "true specific difference" or differentia: the form is a nature that is a limitation on a more general nature or genus.

Lastly, Bacon describes forms as the laws of action or of what constitutes a given nature. "For when I speak of Forms, I mean nothing more than those laws and determinations of absolute actuality, which govern and constitute any simple nature, as heat, light, weight, in every kind of matter and subject that is susceptible of them. Thus the Form of Heat or the Form of Light is the same thing as the Law of Heat or the Law of Light." (Book II, Aphorism 17) The form is the law which governs the process by which a quality is created out of its previous conditions, or how it changes. As Thomas Fowler puts it, it "may be defined as the law of the development or manifestation or production of any given quality or body." The consideration of the preconditions of a nature, along with the laws of its development, gives us the true meaning of "cause," and thus allows us to grasp the connections between "form," "law," and "cause." The "law" is how the form developed out of its pre-existing conditions, and the "cause" is both the conditions and the development combined. That's why Bacon also describes "form" as the source of emanation of a nature or its “coming-to-be”: the form is the law of action for the production of the nature from its pre-existing conditions.

The form is at once the essence (essential, independent and non-derived qualities) and the cause of a nature, and it isn't terribly difficult to understand how this is so. As Thomas Fowler articulates it, "if we are acquainted with Newton's analysis of a white ray of light into the several coloured rays of which it is composed, it is indifferent whether we speak of these rays as constituting (=being the essence of) whiteness, or as producing (=being the cause of) whiteness." (Fowler, p. 59)

As Bacon understands the nature of things, bodies are composed of various simple natures, and thus knowledge of the essence of these composite natures is equivalent to knowledge of the cause of these natures. The implication for human power is that if we were to know the forms of the various simple natures that constitute a given body or substance, a person should be able to artificially reproduce the body in question by superinducing or adding on natures, one on another. In this sense, "form" is also a guide which explains the conditions under which the nature can exist, and thus guides the person in the artificial reproduction of that nature. Accomplishing such a task would complete the subordinate goal of human power: transforming a body. If you know the forms of a certain thing and how they can be superinduced upon one another on a given body, then you can turn any body into the body whose various natures and forms you already know.

So, our next question is: what does one need to find out in order to discover the form?

Latent Processes and Configurations of Bodies

The bodies and effects we see daily have underlying causes for their existence, including causes that are too small or fast to be perceived, and Bacon terms these the latent processes and the configurations/structures of bodies.

To discover the latent processes of natures, one doesn't start with individual natures, but with compound bodies, as they are originally found in nature. So the idea is to inquire into and record how various things come into existence or are changed, such as gold or another metal being generated from its rudiments, or how animals are formed spanning from sexual intercourse to birth. (Book II Aphorism 5) This includes the operations of various natures within things, such as the process of nutrition from taking in food to its assimilation, or the motion of the tongue and other parts to the production of articulate sounds in the case of speaking. Here Bacon is not referring to the macroscopic processes of sex, pregnancy, nutrition, etc. but the hidden, microscopic processes and how these processes generate and transform bodies. In any given body, we must determine the latent processes by determining, "what is lost and escapes; what remains, what is added; what is expanded, what contracted; what is united, what separated; what is continued, what cut off; what propels, what hinders; what predominates, what yields; and a variety of other particulars." (Book II, Aphorism 6) Knowledge of these latent processes is important because without them, the investigation into the forms of natures will be fruitless; in many ways, the latent processes of nature leads us to the more universal laws of action of various bodies and qualities. The importance of latent processes in regard to human power was aptly stated by Carl Brock Sides:

If, for example, I knew that there was a natural latent process consisting, in order, of event-types A, B, C, and D, I could bring about an event of type D by artificially bringing about an event of type B or C and letting nature run its course. If, however, I had knowledge of the laws governing such processes [in other words, if he had knowledge of forms], I might discover that there was another way of bringing about an event of type D, a way that does not require first bringing about an event of type A, B, or C. [Words in brackets are mine.]

One’s knowledge and power will also be severely restricted if one does not possess knowledge of the latent configurations of bodies, the mostly hidden interior arrangement of bodies. Bacon observes that, “no one can endow a given body with a new nature, or successfully and aptly transmute it into a new body, unless he has attained a competent knowledge of the body so to be altered or transformed.” (Book II, Aphorism 7) In the same vein, it can be difficult, if not impossible, to understand the laws governing a complex nature without a knowledge of that body’s latent configuration. We hardly understood much about the Sun and other stars, such as why they produce light and heat, until we learned about their latent configurations through the discoveries made in the atomic theory and other theories in physics, chemistry, and astronomy. Bacon notes that latent configurations of bodies, like forms themselves, can be discovered by “reasoning and true induction.” (Ibid.)

With all of this said, it’s time to finally discuss Bacon’s theory of induction, both what it requires and how it precedes.

A True and Proper Induction

Bacon’s firmly held belief is that a certain method of induction is necessary to gain knowledge of the forms, which is the theoretical aim of all knowledge.

The old form of induction would take sensory evidence of particular instances, and then immediately generalize to the highest principles, with no stages in the middle, and no attempt to cross-examine the evidence contained in the induction. Bacon’s form of induction differs radically from the old view, as the idea of “stages” in reaching the induction, and the need to examine the content of the induction, are presented as the hallmarks and touchstones of a proper induction.

The Stages of Induction, and the Unity of Nature

The stages of induction outline Bacon’s view of epistemology to a large extent. Sense-perception is the basis for all knowledge, including the knowledge to be obtained by induction. From our observations of nature, specifically from producing certain “tables” of observation and experiment, we can generalize to low-level axioms (principles), which Bacon calls “living axioms.” (Book I, Aphorism 104) These are not much different from bare experience, and from them one rises to “medial” or middle axioms; identification of these living and medial axioms is how we reason from perceptual data to the knowledge of forms, and to the fundamental laws of nature. These fundamental laws of nature are not abstract, as Bacon says is the common view: rather, they are the natures of which forms are their limitations. (Book I, Aphorism 104) Bacon is proposing a kind of induction that reaches higher and higher stages of generality, from piecemeal generalizations to the highest level of generalizations: from perception to low-level principles to middle principles to the highest principles and laws of nature.

The old form of induction would only reach the highest and most general laws of nature, which was reached by immediately “leaping” from the facts of experience. Bacon proposes to discover the living, medial, and highest axioms with induction, and to prove them each as well. (Book I, Aphorism 105) Indeed, not only will he use induction to discover and prove axioms in general, but to form our very notions. The proof will depend on the natures which are rejected or excluded from the induction, and on the reasons given for the rejections, and then finally on stating the resulting generalization affirmatively.

Lastly, the old form of induction focuses exclusively on one class of things, whether it’s only “ravens” that are black, or only “swans” which are white, and so on. The new induction will cover all the available instances and classes in a wide variety under its method. Bacon’s view is that there is a sort of “union” or “unity” in nature, that even the most disparate and unlike things possess some underlying similarity, beyond that of sharing a simple nature or even a simple nature’s form (which he terms a “lesser form,” to be contrasted with “great form,” see Book II, Aphorism 26): the unity of nature will point us towards knowledge of its laws and operations. (Book II, Aphorism 27) “For whatever unites nature, though imperfectly, paves the way to the discovery of Forms.” (ibid., Aphorism 26)

Like Bacon’s stages of induction and axiom-formation, the forms themselves have a certain hierarchy, meaning that the “union/unity of nature” has several stages. The lowest step of this union are physical resemblances among concrete bodies, such as the similarities in certain fossils and the skeletons of modern animals—these Bacon calls the conformable instances or instances of analogy, parallel, or physical resemblances (ibid., Aphorism 27); while they do not directly assist in discovering forms, they are very helpful in discovering the very fabric of the universe, and systematizing all that exists within it (such as grouping things together which have close resemblances). The next step higher is the resemblances among certain qualities of a nature’s form and the form itself, which are illuminated by constitutive instances. (ibid., Aphorism 26) While Bacon never explicitly speaks of an even higher stage than this in his work, I think we should note that the stage above resemblances between aspects of a lesser form and the form itself would be the relations between aspects of a great form (in other words, a lesser form, or “true difference”) and the great form itself (the genus)—precisely the object of a perfect induction, in Bacon’s view. Lastly, although this is only my own speculation, the highest stage of this would be the resemblances and relations of all the great forms, the highest laws of nature, which would lead to complete knowledge of the “unity of nature” and of “forms.” With that said, let’s now delve into the details of Bacon’s method of induction.

Comparing, Contrasting, Suggesting, and Excluding

If one can discover the form of a nature, then one can reach an axiom and a well-abstracted and properly defined notion of a nature, and thus one can learn how to produce and superinduce that nature on anything, anytime, anywhere. (John McCaskey, Regula Socratis [Rule of Socrates], p. 260) In order to accomplish this, Bacon presents a three-step procedure: the collection of an exhaustive “Natural and Experimental History,” the “Tables and Arrangements of Instances,” ordered so as to assist our reasoning faculty, and lastly, “Induction.” Due to the enormity of the first step of the task, which would have looked something like modern encyclopedias once completed, Bacon more or less bypasses this “history,” merely adding some guidelines for collecting one’s observations. The main focus of Book II of the Novum Organum is the presentation of the “Tables,” and the method of induction which works from those tables.

Bacon proposes a strict methodology for using induction to discover the forms, and restricts the use of induction for the natures of bodies, not for the bodies themselves. (For information on why this is, consult Dr. McCaskey’s dissertation, Regula Socratis, p. 265-267)

To begin, one considers a given nature by presenting a wide range of known instances which “agree” in the same nature, though the substances themselves are the most unlike. This is already remarkably different from enumerative induction, which focuses on similar members of a single group. Bacon uses the nature of heat, and intends to investigate the Form of Heat. (Book II, Aphorism 11)

What then follows is a list or table of occurrences of heat in very different bodies, such as the rays of the sun during a summer’s day at noon, burning thunderbolts, flames, boiling or even heated liquids, all bodies when near fire (even air), and the internal workings of all animals, whether we can feel their heat or not (like insects). Bacon terms these the “instances agreeing in the nature of heat,” and the table itself the Table of Essence and Presence. (Ibid.) Essentially, this is the “method of agreement,” of noting what is present whenever heat is present, without deciding yet what causes heat. In total, he lists 27 instances which agree with (in other words, possess) the nature of heat.

Next, he produces a table of instances in which heat doesn’t exist, but does this in a limited context: unlike the Table of Presence, he doesn’t want to present a universal list of cases where heat doesn’t exist, since he believes that this would be endless. (Ibid., Aphorism 12) Instead, he will focus on the cases that are similar to the first table (of Presence) in the respect that the nature of heat manifested itself in them, and seeks to contrast them to very similar circumstances in which the nature of heat was absent. To the rays of the sun, Bacon contrasts the rays of the moon, stars, and comets, noting that these rays are not hot to the touch; to the positive instance of thunderbolts, Bacon contrasts certain flashes of light which do not burn and never accompany thunder. These are known as “instances in proximity where the nature of heat is absent,” and the table is called the Table of Deviation or the Table of Absence in Proximity. This is basically the “method of difference,” in which one notes what is absent whenever heat is absent, again without yet concluding on what causes heat. Bacon presents 32 instances of this sort, with at least one instance being contrasted with each affirmative instance of the first table.

The third table presents instances in which the nature of heat varies in degree, which is accomplished by comparing an increase or decrease of heat in the same object, or the different amounts of heat found in different objects when they are being compared. Bacon’s view of forms holds that nothing can be a true form of a nature if it does not decrease or increase as the nature itself decreases or increases. Here, Bacon lays out a continuum of heat, from the degrees of heat that are potential (latent, and imperceptible) to the very first degrees of perceptible heat in animal bodies (noting that feverish heads can be so hot as to burn the hand touching it), to the heat of the sun and other “heavenly bodies,” to the degrees of heat from flames on up to even greater degrees of heat. Importantly, a couple of the instances he names allow him to conclude that motion increases heat, and that compression decreases heat (such as a boot extinguishing a fire). This third table he calls the Table of Degrees or Comparison in Heat. This table corresponds to the “method of concomitant variations,” in which a nature varies in tandem with the heat, but still without a conclusion as to what causes the heat. He lists 41 instances of this kind. (ibid., Aphorism 13)

After the Presentation of Instances to the Understanding (the three tables), the next step is induction, Bacon announces. (ibid., Aphorism 15) The goal of induction is to guide the mind towards the discovery of forms. To discover the form of a nature, after drawing up the three tables and reviewing their instances, one must, “find such a nature as is always present or absent with the given nature, and always increases and decreases with it; and which is […] a particular case of a more general nature.” (Ibid.) Even at this point, one cannot simply begin focusing on the affirmative and positive instances: the result will only be “fancies and guesses and notions ill defined, and axioms that must be mended every day.” Rather, we must begin with negatives, and end with affirmatives only after a sufficient number of exclusions have been made. This “exclusion” or rejection is the first task of induction (in its larger goal of discovering the forms), and the task here is to reject (1) the several natures of an instance which are present when the given nature (heat) is absent; (2) to reject the natures when they are absent but the given nature is present; (3) to reject the natures when those natures in some instance increase but the given nature decreases and (4) to reject any natures which decrease in some instance but the given nature increases. The result of such observations will be the discovery of the form, Bacon proclaims, “solid and true and well defined.” (Ibid.)

The rejection or exclusion will proceed by reviewing the tables and rejecting natures on the authority of the tables: in fact, any nature can be rejected just from one of the instances named in any table. The criticism Bacon made of enumerative inductions applies here as well: a single contradictory instance destroys any guesses or inductions made about the form or cause of some nature. From the heat of the rays of the sun, reject terrestrial nature as the form of heat; from common fires and especially subterranean fires (such as from ignited coal), which are separated from the rays of heavenly bodies, reject the nature of heavenly bodies; on account of boiling water and metals that retain heat but do not ignite, reject light or brightness (such as a lightning flash); on account of the heat that can be transferred to a wide range of bodies by their mere proximity to fire, reject the distinctive compositions of bodies as the cause of heat. This series of rejections is the first step of Baconian induction, which he also terms the Indulgence of the Understanding, or the Commencement of Interpretation, or the First Vintage (or First Harvest): in this case, the First Vintage concerning the Form of Heat. (Ibid., Aphorism 20)

The second step is to reach the genus of the form of heat, the more general nature in which the nature of heat is a particular case. Bacon concludes that heat is a particular case of motion: this is evidenced by flames, boiling liquids, the fact that motion increases heat like in bellows and blasts, the fact that fire and heat seem to cause tumultuous motions in the internal structure of parts of a body which lead to its dissolution, and by the negative fact that fire and heat become extinct in the presence of strong compression, which opposes motion. (Ibid.) Bacon qualifies this relationship between heat and motion, or species and genus, in an important statement:

When I say of Motion that it is as the genus of which heat is a species, I would be understood to mean, not that heat generates motion or that motion generates heat (though both are true in certain cases), but that Heat itself, its essence and quiddity, is Motion and nothing else[…] (Ibid., Aphorism 20)

In the third step of induction, Bacon adds some precautionary remarks about heat, delimiting its specific difference now that the genus has been identified. Sensible heat is not the same as the form of heat, since it is really only the effect of heat on animal perception (what Bacon calls “animal spirits”), and even the heat we sense depends on the disposition of the sense organs, such as hot water feeling ice cold to the chilled skin on our hands. The communication of heat, or its transitive nature, is not the same as the form of heat because heat is one thing, heating is another; heat can be caused by rubbing things together without any preceding heat, which rules out heating as the form of heat, and in any event, the process of heating should be investigated in the more general nature of assimilation or self-multiplication, which is a different inquiry. Lastly, fire is not the form of heat, and even our notion of fire is ill defined, as we call “fire” both common flames and objects heated until they are red.

The fourth and final step of induction (at least in this First Vintage) is to list the specific difference(s), or species, of heat, that which distinguishes heat from other motions and makes it the kind of thing it is. By presenting even more instances to support his conclusions (and even suggesting more experiments), especially by comparing it to the motions of the seeming opposite of heat, cold, Bacon reaches the conclusion that heat is a kind of motion with four specific differences: (1) It’s an expansive motion, (2) an upward motion, (3) a motion checked and exerted through the smaller parts of bodies, and (4) a motion that is rapid, and somewhat violent. The true definition of heat (not just sensible heat, but heat universally) is an expansive motion with an inclination to move upward, and it is a motion in the smaller parts of bodies that is restrained/checked, but is also rapid and violent (rather than sluggish). This is the identification of the species and genus, and is thus the true definition of heat, the true form of heat; the notion of heat is now well defined and properly abstracted, and is no longer an “idol.” We now have a true axiom regarding heat.

Heat is now logically convertible with that kind of motion, in Bacon’s view: heat is that kind of motion.

The aim of human knowledge now completed, the road is opened for the completion of the main and subordinate aim of human power: If you can excite in any natural body a motion of the kind described (i.e. if you can transform the body), then you can generate heat without fail (superinduce the nature of heat on that body), regardless of the nature of the body, so long as it is susceptible to that kind of motion.

Unfortunately, Bacon never finished his account of induction, noting that his investigation into heat was more of a sketchy example than a full-fledged discovery of the nature of heat; he notes that only the First Vintage has been completed, and he has yet to, “describe further aids and supports for the process and how the results are to be refined, adapted, limited, used, and extended to higher-level principles.” (Regula Socratis, p. 267)

Conclusion

Besides his emphasis on experiments in a valid theory of induction, and the articulation of several of its necessary components (the methods of Agreement, Difference, and Concomitant Variations), Bacon should never be forgotten for his stress on the discovery of similarities within differences, that even the most heterogeneous things can have important features in common:

But if any one conceive that my Forms too [in addition to the Platonic, abstract Forms] are of a somewhat abstract nature, because they mix and combine things heterogeneous (for the heat of heavenly bodies and the heat of fire seem to be very heterogeneous; so do the fixed red of the rose or the like, and the apparent red in the rainbow, the opal, or the diamond; so again do the different kinds of death; death by drowning, by hanging, by stabbing, by apoplexy, by atrophy; and yet they agree severally in the nature of heat, redness, death); if any one, I say, be of this opinion, he may be assured that his mind is held in captivity by custom, by the gross appearance of things, and by men’s opinions. For it is most certain that these things, however heterogeneous and alien from each other, agree in the Form or Law which governs heat, redness and death; and that the power of man cannot possibly be emancipated and freed from the common course of nature, and expanded and exalted to new efficients and new modes of operation, except by the revelation and discovery of Forms of this kind. (Book II, Aphorism 27; the words in brackets are my own.)

Induction requires the recognition that things have similarities as well as differences: otherwise, you’ll be surrounded by a world of differences, without any footing to reach any classifications or generalizations.

More than anyone in history, Francis Bacon presented the underpinnings of induction, its essentials, and its goal in relation to human life. His Novum Organum inaugurated the modern discussions and applications of induction, and had a strong influence over the rise of scientific research and methodology. As perhaps the first person ever to link induction with knowledge, causality, and human power/welfare, he should rank among Aristotle, John Locke, and Ayn Rand in showing the practical benefits of philosophical thinking, and demonstrating the need for such thinking.