<< . .

. 2
( : 32)



. . >>

Leibniz. In general they argue that knowledge derives from the intel-
lect, which may be aided or hindered by sense perception. Although
these philosophers differ on how the senses relate to the intellect, they
agree that the intellect alone can grasp truths about reality, through
innate ideas, prior to all sense experience. Descartes undoubtedly
provides the most famous arguments along these lines in his cogito
argument for his existence and his proofs for the existence of God.
Although the senses can contribute to physical science, Descartes
thinks sense perceptions are more likely to interfere with intellectual
intuition. Leibniz conceives the relation between the senses and the
intellect differently, taking sensory experience as a confused form of
thinking. Although he agrees that knowledge of noumena, or things
in themselves, is innate, depending entirely on the intellect, he holds
that there is a correspondence between noumenal reality and phe-
nomenal appearances. His Monadology (1714) is a paradigmatic ratio-
nalist attempt to base metaphysics on logical principles of identity
and non-contradiction.
In contrast to the rationalists™ optimism about the power of reason,
the British empiricists of the modern period “ John Locke (1632“
1704), George Berkeley (1685“1753), and David Hume (1711“76) “
emphasize the role of the senses. “Empiricism” is derived from the
Greek word for experience; on their view all ideas originate in sense
perception and re¬‚ection on our own minds. The intellect alone
cannot know reality; at best it can operate on ideas given through
the senses by such processes as association, comparison, abstraction,
and deduction. In his Essay Concerning Human Understanding (1689),
Locke argues, like Aristotle, that the mind is a tabula rasa or blank slate
at birth; all mental processes begin with sensory stimulation, and the
mind contains no innate ideas. Despite his empiricism, Locke accepts
Introduction to the critical project
8
many of Descartes™s metaphysical beliefs, such as the existence of
God, bodies, and causal connections. Although he thinks knowledge
of reality can never be certain, Locke does not question our capacity
to acquire scienti¬c knowledge, however fallible.
It is a paradox of empiricism that a commonsense theory of knowl-
edge leads ultimately to a profound skepticism. Berkeley takes the ¬rst
steps by arguing that belief in a mind-independent material world is
not only unjusti¬able but incoherent. Thus he rejects Descartes™s
substance dualism in favor of metaphysical idealism “ the view that
all reality consists of minds and their mental states. In his Principles
of Human Knowledge (1710) and Three Dialogues Between Hylas and
Philonous (1713), Berkeley rejects the existence of matter. Neverthe-
less, he retains Descartes™s beliefs in the existence of God and minds
as mental substances.
Hume, of course, argues for the most sweeping skepticism. In his
Treatise of Human Nature (1739), Hume argues against knowledge
of reality outside one™s perceptions, including minds, bodies, and
God. Against the rationalists, Hume makes devastating criticisms of
the capacity of “reason” as a purely intellectual faculty. In place of a
philosophical justi¬cation of metaphysics, he offers a psychological
account of its origins. Appealing to “reason” in a broad sense, includ-
ing the functions of the imagination, Hume claims that metaphysical
beliefs are “natural,” even if not strictly justi¬ed. Although his con-
temporaries failed to appreciate Hume™s brilliance, he effectively put
an end to rationalist metaphysics.
As we saw above, Kant was raised a Leibnizian, taught by stu-
dents of Wolff. Nevertheless, in the 1760s he recognized the power of
Hume™s attack on metaphysics. As he explains in the Prolegomena to
Any Future Metaphysics: “I openly confess that my remembering David
Hume was the very thing which many years ago ¬rst interrupted my
dogmatic slumber and gave my investigations in the ¬eld of specu-
lative philosophy a quite new direction.”5 Kant was less impressed,
however, by Hume™s psychological account of metaphysical belief. So
by 1769, Kant embarked on the ¬rst steps of his critical project.
Kant intends to defend metaphysics and scienti¬c knowledge by
providing an accurate analysis of human reason. His theory is based

5 Theoretical Philosophy after 1781, 57.
Introduction to the critical project 9
on his discovery of synthetic a priori knowledge, judgments that are
both informative and necessary. The problem is to explain how such
judgments arise, as well as to give an account of their truth. Agreeing
with Hume that experience cannot be their source, Kant takes the
“critical turn,” locating such knowledge in the subject. But equally
unhappy with rationalism™s appeal to innate principles, Kant must
offer a new theory of the mental faculties. The key is his view that
human reason, both theoretical and practical, produces synthetic a
priori principles in the course of its natural activities. The Critique of
Pure Reason argues that the necessary mathematical and metaphysical
principles underlying all theoretical knowledge originate in the pure
forms of sensibility and the intellect.
From Kant™s point of view, all thought before him is pre-critical:
he was the ¬rst to offer a systematic, functional justi¬cation of pure
concepts and principles. To do this, Kant invents a new type of
argument, which he calls a “transcendental deduction.” His strat-
egy is to show that a certain type of experience has particular nec-
essary conditions. Thus anyone who accepts the “fact of experience”
must agree that its transcendental conditions or presuppositions are
true. All previous philosophers assumed that there were only two
alternatives: either accept some substantive beliefs dogmatically as
self-evident, or fall into an in¬nite regress of justi¬cation. One hall-
mark of Kant™s brilliance is the way his critical method sidesteps this
dilemma, by exploiting assumptions necessary to frame the skeptical
challenge.
Kant™s view that synthetic a priori knowledge originates in the sub-
jective capacities of the knower results in transcendental idealism.
This is the position that all theoretical knowledge is only of appear-
ances, and that things in themselves are unknowable. Despite its radi-
cal nature, Kant™s idealism offers solutions to two skeptical challenges.
First, while it sets clear limits to metaphysics and empirical science,
it explains how humans can attain knowledge of the spatial-temporal
world. Second, it provides the basis for claiming that knowledge of a
world governed by causal necessities is compatible with the practical
freedom required by the moral law. These interwoven strands of the
critical philosophy “ the analysis of human reason, the justi¬cation
of synthetic a priori knowledge, and transcendental idealism “ will
serve as main themes in this guide.
Introduction to the critical project
10

3. t he struct ure of t h e c r i t i q u e o f p u r e r e a s o n
As mentioned above, Kant™s philosophy is noteworthy for its system-
atic nature. The Critique of Pure Reason is organized around several
fundamental distinctions. After the two Prefaces (the A edition Pref-
ace of 1781 and the B edition Preface of 1787) and the Introduction,
the text is divided into the Doctrine of Elements and the Doctrine
of Method. The ¬rst part explains the a priori contributions of the
mind to experience, and the legitimate and illegitimate use of these
representations. Kant further divides the Doctrine of Elements into
the Transcendental Aesthetic and the Transcendental Logic, re¬‚ect-
ing his basic distinction between the sensibility and the intellect. In
the Transcendental Aesthetic he argues that space and time are pure
forms of intuition inherent in our sensory capacities, accounting for
the a priori principles of mathematics. The Transcendental Logic
is divided into the Transcendental Analytic and the Transcenden-
tal Dialectic. The former defends the legitimate uses of the a priori
concepts, the categories, and their correlative principles of the under-
standing, in attaining metaphysical knowledge. The section titled
the Metaphysical Deduction explains the origin of the categories;
in the Transcendental Deduction, Kant makes the central argument
justifying their application to experience. Following this, the Ana-
lytic of Principles contains detailed arguments for the metaphys-
ical principles correlated with the categories. This section begins
with the Schematism, which explains how the imagination functions
in applying pure concepts to the sensible data given in intuition.
Then follow the detailed arguments for the a priori principles corre-
lated with the schematized categories. The last part of the Doctrine of
Elements, the Transcendental Dialectic, explains the transcendental
illusion that motivates the misuse of these principles beyond experi-
ence. Kant™s most signi¬cant arguments are the Paralogisms of Pure
Reason, the Antinomy of Pure Reason, and the Ideal of Pure Reason,
aimed against, respectively, traditional theories of the soul, the uni-
verse as a whole, and the existence of God. In the Appendix to the
Critique of Speculative Theology Kant explains the positive role of
the transcendental ideas of reason. The Doctrine of Method, which
takes up no more than a sixth of the text, contains four sections, of
Introduction to the critical project 11
which the ¬rst two are most signi¬cant. The Discipline of Pure Rea-
son contrasts mathematical and philosophical methods of proof, and
the Canon of Pure Reason outlines the relation between theoretical
and practical reason, in preparation for the critical moral philosophy.
Here is an outline of the text, listing the main discussions:

1. First and second Prefaces
2. Introduction
3. Doctrine of Elements
A. Transcendental Aesthetic
B. Transcendental Logic
(1) Transcendental Analytic
a. Analytic of Concepts
i. Metaphysical Deduction
ii. Transcendental Deduction
b. Analytic of Principles
i. Schematism (bridging chapter)
ii. System of Principles of Pure Understanding
a. Axioms of Intuition
b. Anticipations of Perception
c. Analogies of Experience
d. Postulates of Empirical Thought (Refutation of
Idealism)
iii. Ground of Distinction of Objects into Phenomena
and Noumena
iv. Appendix on the Amphiboly of the Concepts of
Re¬‚ection
(2) Transcendental Dialectic: Transcendental Illusion
a. Paralogisms of Pure Reason
b. Antinomy of Pure Reason
c. Ideal of Pure Reason
d. Appendix to Critique of Speculative Theology
4. Transcendental Doctrine of Method
A. Discipline of Pure Reason
B. Canon of Pure Reason
C. Architectonic of Pure Reason
D. History of Pure Reason
Introduction to the critical project
12
4. th e second (b ) e d i ti on versi on
The ¬rst important review of the Critique appeared in the January
19, 1782, edition of the G¨ttingischen Anzeigen von gelehrten Sachen.
o
The review was originally based on a sympathetic exposition of Kant™s
arguments by Christian Garve (1742“98), a moral philosopher. The
published version, however, rewritten by J. G. H. Feder (1740“1820),
omitted most of Garve™s interpretation, and emphasized three objec-
tions. First, it mistakenly assimilated Kant™s idealism to Berkeley™s
idealism, which analyzes spatial objects as collections of sense data.
Second, based on this reading, it charged that Kant™s theory could
not distinguish between the real and the imaginary. And ¬nally, it
attacked the distinction between theoretical and practical philoso-
phy, on the grounds that morality is based on common sense. This
misreading and Kant™s own dissatisfaction with the Transcendental
Deduction prompted him to publish a revision in 1787.
In his revised (or B) edition Kant separates his transcendental
idealism from Berkeley™s “empirical” idealism, and reworks several
key arguments. The second edition Preface presents Kant™s critical
approach through the startling metaphor of the Copernican revolu-
tion. Kant also expands his arguments in the Introduction and the
Transcendental Aesthetic. The two major changes in the Analytic
are a completely revised Transcendental Deduction of the categories,
and a new section, the Refutation of Idealism, added to the Ana-
lytic of Principles. Kant reworks the Transcendental Deduction to
address two defects of the earlier edition: a failure to make the unity
of self-consciousness the foundation of the argument, and a lack of
connection to the theory of judgment. In the Refutation of Idealism
Kant clari¬es his idealism. Although the proof is aimed at Descartes™s
view that knowledge of the external world is less certain than self-
knowledge, Kant elucidates the difference between his and Berkeley™s
idealism as well. Because of this addition, Kant also revised the Par-
alogisms section of the Dialectic.
In this text my main purpose is to explain Kant™s arguments intel-
ligibly to the student who has some familiarity with the history of
philosophy. In keeping with the principle of charity, I attempt to give
Kant™s views the most plausible interpretation consistent with the
texts. At the same time I indicate the main strengths and weaknesses
Introduction to the critical project 13
in his views. While it is impossible to evaluate the many criticisms
leveled against Kant, I point out both some clear misunderstandings
and many reasonable questions raised by commentators. And since I
believe it is impossible to understand a philosophy without knowing
the issues engaging the philosopher, as well as the legacy, in general
the discussion situates Kant™s arguments in the context of his times.
c h a p t er 2

The Prefaces and the Introduction




1 . t he a ed ition pre face : th e probl em
of h u ma n re a s on
In the ¬rst edition Preface Kant explains why a critique of human
reason “ the power to know “ is necessary. At Avii he says it is the
nature of reason to ask questions it cannot answer. Although he gives
no examples, these questions are the basis of traditional metaphysical
disputes Kant examines in the Transcendental Dialectic: is the uni-
verse ¬nite or in¬nite in space and time? Is matter in¬nitely divisible
or composed of simple parts? Do humans have free will or are we
determined by causes outside our control? And does the existence of
the universe presuppose a necessarily existent being? We can see how
these questions arise in our everyday thinking. Consider the princi-
ple underlying scienti¬c investigation: “Every event has a cause.” We
“naturally” ask: what caused the earthquake? What causes the earth
to revolve around the sun? What caused the universe? But if these
questions arise naturally, then what is the problem?
In the Dialectic, Kant describes how, in trying to explain reality,
reason ends up in a dilemma: either the explanatory chain contin-
ues forever, or it must end somewhere. The temptation is to ¬nd a
stopping place, to invent an “absolute” to end the series. Examples of
such “absolutes” are God as the cause of the universe, and freely acting
souls as the causes of human actions. The problem with such answers
is that they cannot be veri¬ed by experience. Humans cannot experi-
ence the entire history of the universe, or God, or an immaterial soul
as they can experience everyday events in space and time. As Kant
puts it, once we have conjectured about the existence of things that


14
The Prefaces and the Introduction 15
are not possible objects of experience, then reason has overstepped its
bounds, namely “all possible use in experience” (Aviii).
This is why the traditional metaphysical debates have never been
resolved. Since the Greeks, philosophers have inquired about the
ultimate nature of reality, but once they posited the existence of
“absolutes,” their answers could not be tested by experience. So meta-
physicians could only conjecture rather than make genuine claims to
knowledge. Worse, different philosophers gave opposing solutions,
and thus human reason “falls into obscurity and contradictions”
(Aviii). Because Kant treats these questions at length in the Tran-
scendental Dialectic, here he only points out that the unresolved
debates of metaphysics show that philosophers have been using the
wrong methods. In particular, he will argue that all cognitive claims
must be decidable by reference to experience. (A version of this idea
gains prominence as the “veri¬ability principle” of meaning espoused
by twentieth-century positivists.)
From Aix to Ax Kant describes the battles between dogmatists “
rationalists such as Plato, Descartes, and Leibniz “ and skeptics “
empiricists who questioned the ability to discover the nature of reality.
Kant mentions that Locke attempted a “physiology” of the under-
standing, but this settled nothing, since Locke wrongly assumed that
the answer lies in analyzing how experience arises historically. In fact,
none of Kant™s predecessors identi¬ed the necessary conditions for
knowledge. Until this is done, the traditional problems of metaphysics
cannot be resolved.
Philosophy must start all over again by examining reason itself to
discover what it is capable of knowing. Here as well as in the deduc-
tion of the categories, Kant uses the metaphor of judicial claims to
describe his task, since he thinks of reason as having to establish its
rightful claim to knowledge. As he explains at Axii, a critique of reason
by reason would examine the sources, extent, and limits of our cog-
nitive capacities. More speci¬cally, the critique would answer these
questions:

1. What can reason know independently of experience?
2. Is metaphysical knowledge possible? Are metaphysical questions
meaningful and decidable?
The Prefaces and the Introduction
16
3. What are the limits of knowledge by reason alone? In particular,
Kant is concerned about whether humans can attain knowledge
of things in themselves, or things as they exist independently of
human perceivers.

Like many of Kant™s key terms, the term “reason” (Vernunft) has
several meanings. Kant uses “reason” in three important senses. In
its broadest use, “reason” refers to all subjective processes involved in
knowing. The second sense is less inclusive, and refers to intellectual
as opposed to sensory capacities. The third and narrowest sense of
“reason” refers to the inferential operations involved in logical justi-
¬cations and explanations; in this sense reason is distinguished from
the understanding as the faculty of judging. Kant attributes the errors
of traditional metaphysics to reason in the narrowest sense.
At Axiii Kant makes this extravagant claim: “In this business I
have made comprehensiveness my chief aim in view, and I make bold
to say that there cannot be a single metaphysical problem that has
not been solved here, or at least to the solution of which the key
has not been provided.” Now since philosophers before Kant spent
several thousand years wrangling over metaphysics, the immodesty
of his statement cannot fail to strike the reader. But the next sentence
explains Kant™s optimism. Pure reason is “such a perfect unity” that
its principle supplies the solutions to all metaphysical problems. This
means that the solutions to the metaphysical debates depend on what
the subject contributes to knowledge. Kant will argue that human
reason is governed by a single principle, that it has one and only one
function. Once we understand that function, we can decide which are
the rightful claims to knowledge. (In brief, reason functions to provide
the forms of knowledge.) In any case, an accurate analysis of reason
will guarantee a correct, complete system of metaphysics. Kant will
conclude that some traditional metaphysical claims (e.g., “Every event
has a cause”) are legitimate, whereas others (e.g., “God exists”) are not.
Finally, at Axvi“xvii Kant describes two sides to the deduction of
the categories (a priori concepts), one objective, the other subjective.
The aim of the former is to demonstrate the “objective validity”
of the categories, that is, their applicability to objects of experience.
The latter explains how a priori representations arise from subjective
cognitive processes. Since the Critique ¬rst appeared, commentators
The Prefaces and the Introduction 17
have debated whether Kant™s subjective analysis contains a “faculty
psychology,” like Hume™s theory of custom and association, which
would beg questions at issue in the Critique. As we shall see in chapter
5, although the two sides are interdependent, Kant clearly intends his
account to be epistemological rather than psychological.

2. the b edition pre fac e : ka nt ™s
copernic a n revolut ion
In the 1787 Preface Kant approaches the problem of reason from a dif-
ferent angle. He ¬rst asks whether metaphysics can attain the certainty
of science, or must continue to grope for knowledge. The model used
for comparison is logic, the science of the formal rules of thought.
Kant believes this system “ the elaborated Aristotelian system of syl-
logistic inference “ is complete and certain. It owes its success to the
fact that it abstracts completely from the content of thought, and
merely codi¬es the forms of valid inference. For example, the argu-
ment form modus ponens consists of two premises, one a conditional
“If P, then Q”, the other the antecedent “P” of the conditional, and
the conclusion, the consequent “Q”. Any argument having this form
is deductively valid: if the premises were true, then the conclusion
would have to be true. So, for example, the following two arguments
are both valid because they have the form modus ponens:
1. If the Sun does not revolve around the Earth, then the Earth
revolves around the Sun.
2. The Sun does not revolve around the Earth.
3. Therefore, the Earth revolves around the Sun.
and:
1 . If the universe exists, then it must have been created by an in¬nite
spirit, God.
2 . The universe exists.
3 . Therefore, it must have been created by an in¬nite spirit, God.
The two arguments differ not in validity or logical correctness, but
in the actual truth value of the premises. The ¬rst argument is sound,
since it is valid and the premises are in fact true. Whether the second
argument is sound is controversial, because the ¬rst premise is clearly
The Prefaces and the Introduction
18
debatable. In general, logic cannot decide on the soundness of an
argument, since determining the truth value of claims about reality
requires factual or empirical knowledge. Nevertheless, Kant thinks
any discipline aspiring to be a science must aim for the completeness
and certainty exempli¬ed by logic. Now this strikes contemporary
readers as ironic, since only a century later, the German philosopher
Gottlob Frege inaugurated the development of modern logic by
demonstrating the inadequacies of the logic in which Kant had so
much con¬dence. Despite the limitations of his logic, Kant had a
clear idea about what a formal science was supposed to do.
Although he does not complete the comparison here, Kant™s point
is that if metaphysical knowledge is possible, it will share some char-
acteristics of logic but diverge in others. For Kant, any science must
be based on necessary principles. If scienti¬c principles were only
contingent, one could never be certain that the theories were true.
For this reason all scienti¬c knowledge must be based on a uni¬ed
system of formal rules of thought. But unlike logic, which is purely
formal, metaphysics has a content because it is the science of reality.
We shall see below what kinds of objects metaphysics studies.
At Bix“x Kant distinguishes theoretical from practical reason, a
distinction at the foundation of his entire critical system. Kant bor-
rows this distinction from Aristotle, although he expresses it rather
differently. Essentially the difference is between representing existing
states of affairs, and representing states of affairs that ought to exist.
As Kant puts it, we may know objects in two ways. In the ¬rst, we
apply a concept to an object that is given or exists independently

<< . .

. 2
( : 32)



. . >>