Immanuel Kant, was a German philosopher from Königsberg (now
Kaliningrad) in East Prussia. Kant is often considered one of the
greatest, and is one of the most influential, thinkers of modern
Europe and the last major philosopher of the Enlightenment.
and his philosophy
Kant defined the Enlightenment, in the essay "Answering the
Question: What is Enlightenment?", as an age shaped by the
motto, "Dare to know" (latin: Sapere aude). This involved
thinking autonomously, free of the dictates of external authority.
Kant's work served as a bridge between the Rationalist and Empiricist
traditions of the 18th century. He had a decisive impact on the
Romantic and German Idealist philosophies of the 19th century.
His work has also been a starting point for many 20th century
two interconnected foundations of what Kant called his "critical
philosophy" of the "Copernican revolution" which
he claimed to have wrought in philosophy were his epistemology
(or theory of knowledge) of Transcendental Idealism and his moral
philosophy of the autonomy of reason. These placed the active,
rational human subject at the center of the cognitive and moral
worlds. With regard to knowledge, Kant argued that the rational
order of the world as known by science could never be accounted
for merely by the fortuitous accumulation of sense perceptions.
It was instead the product of the rule-based activity of "synthesis".
consisted of conceptual unification and integration carried out
by the mind through concepts or the "categories of the understanding"
operating on perceptions within space and time, which are not
concepts, but forms of sensibility that are necessary conditions
for any possible experience. Thus the objective order of nature
and the causal necessity that operates within it are products
of the mind in its interaction with what lies outside of mind
regard to morality, Kant argued that the source of the good lies
not in anything outside the human subject, either in nature or
given by God, but rather only in a good will. A good will is one
that acts in accordance with universal moral laws that the autonomous
human being freely gives itself. These laws obligate people to
treat other human beings as ends rather than as means to an end.
Kantian ideas have largely framed or influenced all subsequent
philosophical discussion and analysis. The specifics of Kant's
account generated immediate and lasting controversy. Nevertheless,
his theses that the mind itself makes a constitutive contribution
to its knowledge, which is therefore subject to limits that cannot
be overcome, that morality is rooted in human freedom and acting
autonomously is to act according to rational moral principles,
and that philosophy involves self-critical activity, irrevocably
Immanuel Kant - who was baptized as "Emanuel" but later
changed his name to "Immanuel" - was born in 1724 in
Königsberg, Germany (now Kaliningrad, Russia). He spent his
entire life in and around his hometown, the capital of East Prussia
at that time. His father was a German craftsman from Memel, Germany's
northeasternmost city (now Klaipeda, Lithuania). In his youth,
Kant was a solid, albeit unspectacular, student.
was raised in a Pietist household, a then popular Lutheran reform
movement that stressed intense religious devotion, personal humility
and a literal reading of The Bible. Consequently, Kant received
a stern education -- strict, punitive, and disciplinary -- that
favored Latin and religious instruction over mathematics and science.
Kant later described this period as a time of unhappiness.
Kant enrolled in the University of Königsberg in 1740, at
the age of 16. He studied the philosophy of Leibniz and Wolff
under Martin Knutsen, a rationalist who was also familiar with
the developments of British philosophy and science and who introduced
Kant to the new mathematical physics of Newton. His father's stroke
and subsequent death in 1746 interrupted his studies.
became a private tutor in the smaller towns surrounding Königsberg,
but continued his scholarly research. 1749 saw the publication
of his first philosophical work, Thoughts on the True Estimation
of Living Forces. Kant published several more works on scientific
topics and became a university lecturer in 1755. From this point
on, Kant turned increasingly to philosophical issues, although
he would continue to write on the sciences throughout his life.
the early 1760s, Kant produced a series of important works in
philosophy. The False Subtlety of the Four Syllogistic Figures,
a work in logic, was published in 1762. Two more works appeared
the following year: Attempt to Introduce the Concept of Negative
Magnitudes into Philosophy and The Only Possible Argument in Support
of a Demonstration of the Existence of God. In 1764, Kant wrote
Observations on the Feeling of the Beautiful and Sublime and then
was second to Moses Mendelssohn in a Berlin Academy prize competition
with his Inquiry Concerning the Distinctness of the Principles
of Natural Theology and Morality (often referred to as "the
1770, at the age of 45, Kant was finally appointed Professor of
Logic and Metaphysics at the University of Königsberg. Kant
wrote his Inaugural Dissertation in defense of this appointment.
This work saw the emergence of several central themes of his mature
work, including the distinction between the faculties of intellectual
thought and sensible receptivity.
At the age of 46, Kant was an established scholar and an increasingly
influential philosopher. Much was expected of him. In response
to a letter from his student, Markus Herz, Kant came to recognize
that in the Inaugural Dissertation, he had failed to account for
the relation and connection between our sensible and intellectual
faculties. He also credited David Hume with awakening him from
"dogmatic slumber" (circa 1770). Kant would not publish
another work in philosophy for the next eleven years.
spent his silent decade working on a solution to the problems
posed. When he emerged from his silence in 1781, the result was
the Critique of Pure Reason. Although now uniformly recognized
as one of the greatest works in the history of philosophy, this
Critique was largely ignored upon its initial publication. The
book was long, over 800 pages in the original German edition,
and written in a dry, scholastic style.
received few reviews, and these failed to recognize the Critique's
revolutionary nature. Kant was disappointed with the work's reception.
Recognizing the obscurity of the original treatise, he wrote the
Prolegomena to any Future Metaphysics in 1783 as a summary of
its main views and he encouraged his friend, Johann Schultz, to
publish a brief commentary of the Critique of Pure Reason.
reputation gradually rose through the 1780s, sparked by a series
of important works: the 1784 essay, "Answer to the Question:
What is Enlightenment?"; 1785's Groundwork of the Metaphysics
of Morals (his first work on moral philosophy); and, from 1786,
Metaphysical Foundations of Natural Science. But Kant's fame ultimately
arrived from an unexpected source.
1786, Karl Reinhold began to publish a series of public letters
on the Kantian philosophy. In these letters, Reinhold framed Kant's
philosophy as a response to the central intellectual controversy
of the era: the Pantheism Dispute. Friedrich Jacobi had accused
the recently deceased Lessing (a distinguished philosopher of
the period) of Spinozism. Such a charge, tantamount to atheism,
was vigorously denied by Lessing's friend Moses Mendelssohn, and
a bitter public dispute arose between them.
controversy gradually escalated into a general debate over the
values of the Enlightenment and of reason itself. Reinhold maintained
in his letters that Kant's Critique of Pure Reason could settle
this dispute by defending the authority and bounds of reason.
Reinhold's letters were widely read and made Kant the most famous
philosopher of his era.
Immanuel Kant, detail from a 1791 watercolour by Gottlieb DoepplerKant
published a second edition of the Critique of Pure Reason in 1787,
heavily revising the first parts of the book. Most of his subsequent
work focused on other areas of philosophy. He continued to develop
his moral philosophy, notably in 1788's Critique of Practical
Reason (known as the second Critique) and 1797's Metaphysics of
1790 Critique of Judgment (the third Critique) applied the Kantian
system to aesthetics and teleology. He also wrote a number of
semi-popular essays on history, religion, politics and other topics.
These works were well received by Kant's contemporaries and confirmed
his preeminent status in eighteenth century philosophy. There
were several journals devoted solely to defending and criticizing
the Kantian philosophy.
despite his success, philosophical trends were moving in another
direction. Many of Kant's most important disciples (including
Reinhold, Beck and Fichte) transformed the Kantian position into
increasingly radical forms of idealism. This marked the emergence
of German Idealism. Kant was against these developments and publicly
denounced Fichte in an open letter in 1799. It was one of his
final philosophical acts. Kant's health, long poor, turned for
the worst and he died in 1804. His unfinished final work, the
fragmentary Opus Postumum, was (as its title suggests) published
A variety of popular beliefs have arisen concerning Kant's biography
and legend. It is often held, for instance, that Kant was a late
bloomer, that he only became an important philosopher in his mid-50s
after rejecting his earlier views. While it is true that Kant
wrote his greatest works relatively late in life, there is a tendency
to underestimate the value of his earlier works. Recent Kant scholarship
has devoted more attention to these "pre-critical" writings
and has recognized a degree of continuity with his mature work.
common myth concerns Kant's personal mannerisms. It is often held
that Kant lived a very strict and predictable life, leading to
the oft-repeated story that neighbors would set their clocks by
his daily walks. Again, this is only partly true. While still
young, Kant was very gregarious and, though he never married,
he remained fond of dinner parties through most of his life. Only
later in his life, under the influence of his friend, the English
merchant Joseph Green, did Kant adopt a more regulated lifestyle[citation
Kant developed his moral philosophy in three works: Groundwork
of the Metaphysic of Morals (1785), Critique of Practical Reason
(1788), and Metaphysics of Morals (1798).
three works proceed by a method of taking the "rational [,
obvious, and everyday] knowledge of the moral to the philosophical
[knowledge of the moral]" in the Groundwork - and also making
necessary the moral works that followed; and then, in those latter
works, following a method of using "practical reason",
based only upon things about which reason can tell us, and not
deriving any principles from experience, to reach conclusions
which are able to be applied the world of experience (in the second
part of The Metaphysic of Morals).
is known for his theory that there is a single moral obligation,
which he called the Categorical Imperative, which is derived from
the concept of duty. It is from the Categorical Imperative that
all other moral obligations are generated, and by which all moral
obligations can be tested. He believed that the moral law is a
principle of reason itself, and is not based on contingent facts
about the world, such as what would make us happy. Accordingly,
he believed that moral obligation applies to all and only rational
categorical imperative is an unconditional obligation; that is,
it has the force of an obligation regardless of our will or desires.
(Contrast this with hypothetical imperative.) Kant's categorical
imperative was formulated in three ways, which he believed to
be roughly equivalent (although many commentators do not):
first formulation (Formula of Universal Law) says: "Act as
if the maxim of thy action were to become by thy will a universal
law of nature."
The second formulation (Formula of Humanity) says: "Act that
you use humanity, whether in your own person or in the person
of any other, always at the same time as an end, never merely
as a means."
third formulation (Formula of Autonomy) is a synthesis of the
first two. It says that we should so act that we may think of
ourselves as legislating universal laws through our maxims, in
a possible Kingdom of Ends. We may think of ourselves as such
autonomous legislators only insofar as we follow our own laws.
of the first formulation
The most popular interpretation of the first formulation is called
the "universalizability test." An agent's maxim, according
to Kant, is his "subjective principle of volition" —
that is, what the agent believes is his reason to act. The universalizability
test has five steps:
Find the agent's maxim. The maxim is an action paired with its
motivation. Example: "I will lie for personal benefit."
Lying is the action, the motivation is to get what you desire.
Paired together they form the maxim.
2. Imagine a possible world in which everyone in a similar position
to the real-world agent followed that maxim.
3. Decide whether any contradictions or irrationalities arise
in the possible world as a result of following the maxim.
4. If a contradiction or irrationality arises, acting on that
maxim is not allowed in the real world.
5. If there is no contradiction, then acting on that maxim is
permissible, and in some instances required.
Kant was an advocate of constitutional republicanism. He opposed
democracy, believing that majority rule posed a threat to individual
liberty. He says, "Democracy is necessarily despotism, as
it establishes an executive power contrary to the general will;
all being able to decide against one whose opinion may differ,
the will of all is therefore not that of all: which is contradictory
and opposite to liberty." (Perpetual Peace, II, 1795)
Kant's most powerful and revolutionary effect on philosophy, which
changed forever its meaning, modes of thinking, and language(s),
was not "positive" in the sense of producing specific
assertions about the world that have become accepted truths, as
in the positive sciences. Rather it was "negative" in
the sense of restricting the areas about which such knowledge
was possible — by making philosophy "critical"
idea of "critique" was to examine the legitimate scope
of the mind or of knowledge. In this regard the "critique
of pure reason", which was also the title of his most important
work (see below and Critique of Pure Reason), meant examining
what certain and legitimate knowledge human beings could arrive
at simply by thinking about things independently of experience
and perception, with his conclusion being: not very much.
to Kant, the entire mode of functioning of most philosophy was
drawing conclusions about the nature of the universe, of God,
or of the soul simply by logical thinking about them, by what
seemed to make sense through "a priori" thinking, i.e.
thinking on purely logical grounds. For this sort of thinking
it must be the case that God or the universe is this way or that
way, because it makes sense logically.
in the history of philosophy, for every philosophical theory that
God or the universe or the mind must be one way, some philosopher
arrived at another theory stating that it must be precisely the
opposite way. Kant called this unproductive, unresolvable, back-and-forth,
dogmatic thinking the "dialectic of pure reason". That
is, it was an inevitable consequence of trying to arrive at knowledge
on purely logical grounds independently of experience or of scientific
knowledge based on the evidence of the senses.
Kant, this entire style of pursuing knowledge was bankrupt and
must be abandoned. According to Kant, philosophy must henceforth
operate within the narrow "limits of pure reason" and
recognize that most positive knowledge could come only through
the sciences based on sense perception and not through metaphysics,
which was about things of which we could never have direct sense
philosopher Arthur Schopenhauer was strongly influenced by Kant's
transcendental idealism. Schopenhauer accepted the distinction
between two kinds of knowledge: the world perceived as phenomenon
and also thought of as non-phenomenon (thing-in-itself). For Kant,
the thing-in-itself cannot be an object of perceived experience.
But, for Schopenhauer, the thing-in-itself can be experienced
as the basis of that which, in animal life, is called "will,"
"desire," or urge. Schopenhauer claimed that the will
as such, as thing-in-itself, is the inner, essential nature of
the whole experienced world.
important philosophers and schools of thought, such as German
Idealists, neo-Thomists and other theologically oriented philosophers,
and Heidegger's "fundamental ontology" have refused
to accept the limitations that Kant imposed upon philosophy and
attempted to come up with new metaphysical systems about "the
Absolute", "God", or "Being" , although
even these philosophers have generally tried doing so by taking
Kant into account.
however, post-Kantian philosophy has never been able to return
to the style of thinking, arguing, and asserting conclusions that
characterized philosophy before him. In this way, Kant was correct
in asserting that he had brought about a "Copernican revolution"
in philosophy. According to Kant, Copernicus's revolution in the
understanding of the cosmos lay in taking the position of the
observer into account. This explained why it looks as though the
sun revolves around the earth even though in reality the earth
revolves around the sun.
the observer's position into account prevents the unaware projection
of the observer's perception or point of view onto the picture
of the universe. Kant saw his own Copernican revolution in philosophy,
analogously, as consisting in taking the position of the knower
into account and thereby preventing the unaware projection of
the knower's way of thinking ("pure reason") onto the
philosophical map of reality.
to Kant, it was philosophers unawarely doing this that had created
the illusions of metaphysics that dominated the prior history
of philosophy. Kant saw this revolution, in turn, as being part
of "Enlightenment" (as conceived of in the Age of Enlightenment)
and the creation of an enlightened citizenry and society freed
from dogmatism and irrational authority.
wider influence not only in philosophy but in the humanities and
social sciences generally lies in the central concept of the Critique
of Pure Reason, namely that it is the synthesizing, unifying,
constitutive activity of the subject of knowledge that is at the
basis of our having an ordered world of experience and of the
objects of knowledge themselves. This idea has spread out through
many intellectual disciplines in which it has manifested itself
in different forms, for example:
from Marx's notion, in social theory, of the constitutive role
of human labor in the creation of history and society
2. through Freud's notion, in psychology, that the activity of
the ego produces the reality principle
3. through Durkheim's notion, in sociology, that society creates
collective consciousness through social categories
4. through Chomsky's notion, in linguistics, of transformational
5. to current notions, in several of the humanities and social
sciences, regarding the "social construction of reality"
(Berger & Luckmann, 1966).
6. In this way Kant's conception of synthesizing, ordering mental
activity has become central to modern intellectual culture.
His tomb and its pillared enclosure outside the cathedral in Kaliningrad
are some of the few artifacts of German times preserved by the
Soviets after they conquered the city in 1945. A replica of a
statue of Kant that stood in front of the university was donated
by a German entity in 1991 and placed on the original pediment.
Near his tomb is the following inscription in German and Russian,
taken from the "Conclusion" of his Critique of Practical