IMMANUEL KANT: REHABILITATING REASON (WITHIN STRICT LIMITS References: 1.Norman Melchert, The Great Conversation: A Historical Introduction to Philosophy,

IMMANUEL KANT: REHABILITATING REASON (WITHIN STRICT LIMITS

References:1. Norman Melchert, The Great Conversation: A

Historical Introduction to Philosophy, 2nd Edition2. Prof. Dale Cannon, Phl 201:BEING AND

KNOWINGWEBSITE. http://www.wou.edu/las/humanities/cannon/know.htm

3. Kant’s Theory of Knowledge: Transcendental Idealism. www.hu.mtu.edu/~tlockha/h2700kantknowledge.doc

INTRODUCTION

• David Hume published A Treatise of Human Nature at the age of 23.

• Immanuel Kant published The Critique of Pure Reason at the age of 57.

• Kant published very late in life because it has taken him some time to understand the devastating critique of Hume, “that acute man”.

David Hume: “That Acute Man”• “ I openly confess that my

remembering David Hume was the very thing which many years ago first interrupted my dogmatic slumber and gave my investigations in the field of speculative philosophy a quite new direction. (P, 5)

• … since the origin of metaphysics so far as we know its history, nothing has ever happened which could have been more decisive to its fate than the attack made upon it by David Hume. (P, 3)

AIM OF KANT

• To solve what he calls “Hume’s problem”.

• What is it?

– Whether the concept of cause is indeed objectively vacuous, a fiction whose origin can be traced to a merely subjective and instinctive habit of human nature.

• This causes Kant’s awakening from his dogmatic slumber.

THE DOGMATISM THAT HUME DEBUNKED

• The apparent nature of human thought to recognize no limits.

• How come?– Human thought moves easily and without

apparent strain from bodies to souls, from life in this world to life after death, from material things to God.

– Human thought is so fertile most esp. when it moves out beyond the ground of experience – and yet how certain people feel about their own views.

KANT SECONDED HUME’S POSITION

• With Mathematics, there is no problem as to the independence of knowledge from experience.

• But it does not follow that this knowledge can be extended indefinitely in a realm beyond experience.

KANT’S SUGGESTION

• Human thought needs a medium that supplies “resistance,” some discipline, to work properly.

• Why should a resistance be supplied?

– In a resistance-free environment, everything is equally possible (as long as formal contradiction is avoided), and the conflicts of dogmatic believers (philosophical, religious, or political) are inevitable.

• “The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would be still easier in empty space. It was thus that Plato B9 left the world of the senses, as setting too narrow limits to the understanding, and ventured out beyond it on the wings of the ideas, in the empty space of the pure understanding. He did not observe that with all his efforts he made no advance -- meeting no resistance that might, as it were, serve as a support upon which he could take a stand, to which he could apply his powers, and so set his understanding in motion. “ (CPR 47, Kemp)

KANT’S CONVICTION

• Hume is right to pinpoint EXPERIENCE as the medium that disciplines reason, as the limit within which alone reason can legitimately do its work.

KANT’S DOUBT ABOUT HUME’S UNDERSTANDING OF EXPERIENCE

• The unacceptable consequence of Hume’s analysis of experience vis-à-vis the principle of causality.

• Newtonian science’s becoming an irrational and unjustified fiction.

• Why?– For Hume all our knowledge of matters of fact beyond

present perception and memory are founded on the relation of cause and effect.

– And causes are nothing more than projections onto a supposed objective world from a feeling in the mind.

KANT’S CONVICTION IN THE NEWTIONIAN SCIENCE

• The latter must be a rationally justified knowledge.

• If Hume’s examination of reason forces us to deny that we have this knowledge, something must be wrong with Hume’s analysis.

• Kant said: – What we need is a more thorough and accurate critique of

reason – a critique that will lay out its structure, its relationship to its objects, and inscribe precisely the line that sets the limits within which it can legitimately work.

REPRESENTATIONAL THEORY OF KNOWLEDGE AND PERCEPTION

• CLASSICAL ARISTOTELIAN DEFINITION OF TRUTH: To say of what is that it is, and of what is not that it is not, is true.

– Truth (and knowledge, too) is a matter of getting what we say (or believe) lined up to correspond to what there is.

– We acquire knowledge and truth when our thoughts “conform to objects”.

– Assumption:

• Objects are there, completely independent of our apprehension of them.

• GET IT RIGHT OR CORRECT: When our beliefs are brought to correspond to these independently existing things.

HUME’S OBJECTION OF THE REPRESENTATIONAL THEORY OF KNOWLEDGE AND PERCEPTION

• According to Hume, this is impossible.

– To know whether an idea corresponds to some independent object, we would have to be able to compare that idea with the idea-less object.

– On the basis of mere concepts alone, we can know nothing at all about objects existing outside our minds.

– Ideas that have their origin in experience (e.g. green, warm, solid) can go no further than experience.

– And ideas that don’t (e.g. cause) are mere illusions.

• RTKP summarized:

– All this follows if (1) we are acquainted only with the ideas in our experience, (2) objects are thought to exist independently of our experience, and (3) knowledge requires that we ascertain a correspondence between ideas and objects.

KANT’S REVOLUTIONARY SUGGESTION

• What if this assumption is wrong?

– What if, to be an object at all, a thing has to conform to certain concepts?

– What if objects couldn’t exist – simply couldn’t be in any sense at all – unless they were related to a rational mind, set in a context of rational concepts and principles?

• The same is true in the world of the intellect

– Perhaps the object of experience are (at least in part) the result of a construction by the rational mind.

– If so, they have no reality independent of that construction.

KANT’S COPERNICAN REVOLUTION• Objects of our experience are merely apparent, not

independently real.

• If this is so, it may well be that concepts like CAUSATION, which cannot be abstracted from experience (the lesson of Hume), still apply to experience, simply because objects of experience that are not structured by that concept are inconceivable.

• The suggestion is that the rational mind has a certain structure, and whatever is knowable by such a mind must necessarily be known in terms of that structure.

• This structure is not derived from the objects known.

• It is imposed on them – but not arbitrarily, since the very idea of an object not so structured makes no sense.

CPR’S CENTRAL THESIS

• Knowledge of the world is possible because the self – the transcendental self or ego – determines the structure of our every experience.

• Kant: “Hitherto it has been assumed that our knowledge must conform to objects. But all attempts to extend our knowledge of objects by establishing something in regard to them a priori, by means of concepts, have, on this assumption, ended in failure. We must therefore make trial whether we may not have more success in the tasks of metaphysics if we suppose that objects must conform to knowledge.” (CPR, p. 75)

CRITIQUE• ASSUMPTION: A rational mind can have some

knowledge.

• PROBLEM: How does the mind manage it?

• ANSWER: through a CRITIQUE

• N.B.: A “critical” philosophy is not one that criticizes, in the carping, censorious way where “nothing is ever right.”

• CRITIQUE is the attempt to get behind knowledge claims and ask, What makes them possible?

OBJECTS OF HUMAN KNOWLEDGE (4 MAIN CLASSES)

• FOUR CRITICAL QUESTIONS:

1. How is mathematics possible?2. How is natural science possible?3. How is metaphysics possible?4. How is morality possible?

• PURPOSE: not to develop them but to look at the rational foundations on which these disciplines rest.

• MEANING?: What structure, capacities, and concepts must reason have for it to be able to do mathematics, for instance?

TRANSCENDENTAL INQUIRY

• An inquiry that reaches back into the activities of the mind and asks how it produces its results.

• The kind of investigation that his CPR utilizes.

• Critique of Reason: a critical examination of the way a rational mind works.

JUDGMENT: SYNTHETIC A PRIORI JUDGMENT

• Kant's aim was to move beyond the traditional dichotomy between rationalism and empiricism.

• The rationalists (dogmatism) had tried to show that we can understand the world by careful use of reason; this guarantees the indubitability of our knowledge but leaves serious questions about its practical content.

• The empiricists (skepticism), on the other hand, had argued that all of our knowledge must be firmly grounded in experience; practical content is thus secured, but it turns out that we can be certain of very little.

Genuine Knowledge as Universal and Necessary Knowledge

• HOW?:

• He agrees with the rationalists that there is such knowledge, but only of the basic assumptions of the sciences of physics and mathematics.

• With the empiricists he agrees that we can know only what begins in, or that which we can experience: the senses furnish the materials of knowledge and the mind arranges them in ways made necessary by its own nature.

• Hence we have universal and necessary knowledge of the order of ideas, though not of things-in-themselves.

• Nevertheless things-in-themselves exist; we can think of them but not know them

Kant’s Problem of Knowledge

• What is knowledge and how is it possible?

• Knowledge always appears in the form of judgments in which something is affirmed or denied

• “Thoughts without content are empty. Intuitions without concepts are blind.”

• “Though knowledge comes from experience, not all knowledge arises from experience.

“Though knowledge comes from experience, not all knowledge arises from experience.”

• 2 Aspects of Knowledge:– content—a posteriori knowledge: received

by the mind in experience– form—a priori knowledge: imposed by the

mind on experience• Content—sense-data: colors, sounds, smells,

tastes, touch• Form—spatiality, temporality, causality,

objecthood, unity of consciousness, “categories of understanding” (e.g., quality, quantity, identity)

• Hume: divided knowledge into relations of ideas (semantic) and matters of fact (epistemological).

Varieties of Judgment

• (1) EPISTEMOLOGICAL (By reference to the origin of our knowledge of them: Does a bit of knowledge rest on experience, or not?)

• A priori judgments: can be known to be true without any reference to experience, strictly universal.

– E.g., “7 + 5 = 12”

• A posteriori judgments: must appeal to experience to determine its truth or falsity.

– E.g., “The table is brown.”

A PRIORI JUDGMENT• A priori truths are truths that allegedly cannot be derived

from sense experience and therefore are supposed to hold true independently of sense experience. 

• Their truth is not contingent upon what we find in experience.

1. . A priori truths are the special concern and interest of rationalism.• More generally, rationalists maintain that they are the

special concern and interest of philosophy.  • Even empiricist principles, say rationalists, are putative a

priori truths, for they can't be justified on empirical grounds.

2. Empiricists maintain that the only a priori truths are the analytic truths of mathematics and logic, which tell us nothing about objective reality but only about relations of ideas.

3. They are what dialectical inquiry aims at discovering. 4. They are universal, certain, unchanging, and necessary (non-

contingent).

A POSTERIORI JUDGMENT• A posteriori (or empirical) truths are truths that derive

from and are dependent upon sensory experience.  • Their truth is contingent upon what we find in experience. 1. Empiricists maintain that all synthetic truths, truths about

reality that are not simply empty or analytic truths, are a posteriori truths.  • Consequently, they maintain that there are no a priori

synthetic truths. 2. Rationalists maintain that, while many synthetic truths,

truths about contingent, non-necessary things and events in the world are a posteriori, other synthetic truths are a priori and are universal, unchanging, certain, and necessary.  • This is not, however, to say that everyone is aware of these

truths.  • Nor is it to say that a given person's understanding of these

truths is absolutely certain, complete, an unchanging.

• (2) SEMANTIC (According to the information conveyed as their content: How do the meanings of the words we use to express that knowledge relate to each other?)

• Analytic judgment: its denial yields a contradiction.• E.g., “All bodies are extended.”• If it is true, it is necessarily true.• The opposite of an analytic judgment is not possible.

• Synthetic judgment: simply explicate or analyze a concept.

• E.g., “Every event has a cause.”• The concept having a cause is not part of the concept being

an event.• The opposite of synthetic judgment is always possible.

ANALYTIC JUDGMENT• Analytic Statements (what Hume called "relations of

ideas") • An analytic statement attributes a property to something,

and that property is already implicit in the definition of that object or concept.  (E.g., "A square has four sides." And "A bachelor is unmarried.")

1. It is necessary.  • Its denial results sooner or later in a contradiction.

2. It is universal (so far as the same definition is assumed).3. It is unchanging or eternal.4. It is certain (though not necessarily subjectively certain).5. If the definitions on which the statement is based are

discovered (as rationalists claim), then such truths tell us important things about the world.

6. But if the definitions are simply invented or stipulated, such truths are trivial.

SYNTHETIC JUDGMENT• Synthetic Statements (what Hume called "matters of fact") • A synthetic statement attributes a property to something,

but that property goes beyond what is contained within the definition of the object or concept involved.  (E.g., "This page is white.“

1. Its denial does not result in a contradiction.  In other words, its denial is at least conceivably possible in the abstract.

2. We can know which is true (the original statement or its denial), only on the basis of some independent test.– Empiricists maintain that we can determine the

truth of such statements only on the basis of sense perception, or they are nonsense.

– Rationalists maintain that we can determine the truth of some synthetic statements through dialectical inquiry, and thus arrive at certain necessary, universal, eternal truths.

SYNTHETIC JUDGMENT 23. True synthetic statements tell us matters about the world

that are of practical value and usefulness.– But the world thus described, according to empiricist

assumptions, is entirely contingent and not necessary in any of its features.

• Empiricists maintain that a synthetic statement's universality cannot be known in advance of actually  checking with sense perception, so it is forever uncertain.

• Similarly, empiricists maintain that a synthetic statement does not express an eternal, forever unchanging truth (with the exception of statements asserting something to be true of a state of affairs at a certain time).  New circumstances can bring about its falsity, or make a statement which is presently false become true.

– Rationalists, however, hold that some synthetic truths -- not all truths but the most important truths about the world, on which true wisdom depends -- are necessary, universal, eternal, and certain.

FOUR CLASSES OF JUDGMENT

• Analytic a posteriori judgments cannot arise, since there is never any need to appeal to experience in support of a purely explicative assertion.

• Synthetic a posteriori judgments are the relatively uncontroversial matters of fact we come to know by means of our sensory experience.

• Analytic a priori judgments include all merely logical truths and straightforward matters of definition; they are necessarily true.

• Synthetic a priori judgments are the crucial case, since only they could provide new information that is necessarily true.

• CONSEQUENT: Unlike his predecessors, Kant maintained that synthetic a priori judgments not only are possible but actually provide the basis for significant portions of human knowledge.

How are Synthetic A Priori Judgments Possible?

• Possible in Mathematics and Natural Sciences: depends on them for its power to explain and predict events

• Examples:

• the interior angles of any triangle add up to a straight line • Anything material falls toward the center of the earth.

• Kant supposed, no one will ask whether or not we have synthetic a priori knowledge; plainly, we do.

• The question is, how do we come to have such knowledge? If experience does not supply the required connection between the concepts involved, what does?

• Kant's answer is that we do it ourselves.

Deduction of the Categories• I. QUANTITY

• 1. UNIVERSAL (Unity) “All metals are elements.” • 2. PARTICULAR (Plurality) “Some animals are four-

legged.” • 3. SINGULAR (Totality) “GMA is President of the

Philippines.”

• II. QUALITY

• 4. AFFIRMATIVE (Reality) “Heat is a form of motion.” • 5. NEGATIVE (Negation) “No men are angels.” • 6. INFINITE (Limitation) “Mind is unextended.”

• III. RELATION

• 7. CATEGORICAL (Inherence And Subsistence) “This body is heavy.”

• 8. HYPOTHETICAL (Causality And Dependence) “If air is warm, its molecules move fast.”

• 9. DISJUNCTIVE (Community) “The substance is either fluid or solid.”

• IV. MODALITY

• 10. PROBLEMATIC (Possibility – Impossibility) “This may be a poison.”

• 11. ASSERTIVE (Existence – Nonexistence) “This is a poison.”

• 12. APODICTIC (Necessity – Contingency) “Every effect must have a cause.”

Analogies of Experience

• KANT maintained that we are justified in applying the concepts of the understanding to the world as we know it by making a priori determinations of the nature of any possible experience.

• Each concept of relation, which governs how we understand the world in time, establishes one of the preconditions of experience under one of the modes of time: duration, succession, and simultaneity.

The Analogies of Experience

• Substance: The experience of any change requires not only the perception of the altered qualities that constitute the change but also the concept of an underlying substance which persists through this alteration.

• Cause: The experience of events requires not only awareness of their intrinsic features but also that they be regarded as occurring one after another, in an invariable regularity determined by the concept of causality.

• Community: the experience of a world of coexisting things requires not only the experiences of each individually but also the presumption of their mutual interaction.

PHENOMENA AND NOUMENA

• Phenomena are the appearances, which constitute our experience.

• Noumena are the (presumed) things themselves, which constitute reality.

• All of our synthetic a priori judgments apply only to the phenomenal realm, not the noumenal.

• Since the thing-in-itself (Ding an sich) would by definition be entirely independent of our experience of it, we are utterly ignorant of the noumenal realm.

• Thus, on Kant's view, the most fundamental laws of nature, like the truths of mathematics, are knowable precisely because they make no effort to describe the world as it really is but rather prescribe the structure of the world as we experience it.

The Aim of Metaphysics

• The synthetic a priori judgments of metaphysics are much more difficult to explain because the forms of intuition and concepts of understanding are useless, since they find application only in the realm of our experience, while metaphysics seeks to transcend experience completely, in order to discover the nature of reality itself as comprehended under pure reason.

• Since the aim of metaphysics is genuine knowledge of the noumena, synthetic a priori judgments in metaphysics must be grounded upon truly transcendental ideas, which are regarded as applicable to things in themselves independently of our experience of them.

The Transcendental Ideas

• The Psychological Idea is the concept of the soul as a permanent substance which lives forever.

• The Cosmological Idea is the concept of a complete determination of the nature of the world as it must be constituted in itself.

• The Theological Idea is the concept of an absolutely perfect and most real being (or god).

• Conclusion: Metaphysical speculation about the ultimate nature of reality invariably fails.

• Ideas such as God, freedom, immortality, the world, first beginning, and final end have only a regulative function for knowledge, since they cannot find fulfilling instances among objects of experience.

The Limits of Reason

• What most clearly is not possible is any legitimate synthetic a priori judgment about things in themselves.

• Both sensible intuition and the understanding deal with the conditions under which experience is possible.

• The whole point of speculative metaphysics is to transcend experience entirely in order to achieve knowledge of the noumenal realm.

• Here, only the faculty of reason is relevant, but its most crucial speculative conclusions, its deepest convictions about the self, the world, and god, are all drawn illegitimately.

Possible for Reason

• What is possible—indeed, according to Kant what we are bound by our very nature as rational beings to do—is to think of the noumenal realm as if the speculative principles were true (whether or not they are).

• By the nature of reason itself, we are required to suppose our own existence as substantial beings, the possibility of our free action in a world of causal regularity, and the existence of god.

• The absence of any formal justification for these notions makes it impossible for us to claim that we know them to be true, but it can in no way diminish the depth of our belief that they are.

• The rational human faculties lead us to the very boundaries of what can be known, by clarifying the conditions under which experience of the world as we know it is possible.

– Beyond those boundaries our faculties are useless.

– The shape of the boundary itself naturally impels us to postulate that the unknown does indeed have certain features, but these further speculations are inherently unjustifiable.

• The only legitimate, "scientific" metaphysics that the future may hold would be a thoroughly critical, non-speculative examination of the bounds of pure reason, a careful description of what we can know accompanied by a clear recognition that our transcendental concepts (however useful they may seem) are entirely unreliable as guides to the nature of reality.