Immanuel Kant’s Epistemology:
Categories as conceptual schema
OR solving the issues of innate knowledge,
and the difficulties of sensory knowledge
Some anecdotes about Kant
• Lord Macaulay said in 1848: "November 23d. I received to-day a
translation of Kant from Ellis's friend at Liverpool. I tried to read it,
but found it utterly unintelligible, just as if it had been written in
Sanskrit. Not one word of it gave me any thing like an idea except a
Latin quotation from 'Persius.' It seems odd that in a book on the
elements of metaphysics…I should not be able to comprehend a
word.”
• A man of precise habits: would stroll every day, for exactly one hour,
eight times up and down the same street.
• The street came to be called “The Philosopher’s Walk.”
• So punctual, that the housewives of Königsberg set their clocks by
the time he took his walk.
Life (1724-1804)
• Born in Königsberg, Prussia (now part of Russia) in 1724.
• Went to university in his home town and then became a professor
there.
• Never left his home town, never married, never traveled more than
60 miles from it, and didn’t leave it at all during a forty year stretch.
• Prodigious output of philosophical work – major contributions to
epistemology, deontology, aesthetics
• Author of three of the greatest works in the history of philosophy.
– The Critique of Pure Reason (1781) – on Epistemology
– The Critique of Practical Reason (1788) – on Ethics
– The Critique of Judgment (1790) – on Aesthetics
• Died, very sadly, totally senile, at Königsberg in 1804.
The ‘Copernican Revolution in Philosophy’
• Kant famously says that his epistemology effects a ‘Copernican
Revolution’ in philosophy.
• Copernicus put the sun at the centre of the solar system and pointed
out that the apparent movement of the stars is partly due to the
movement of the human observer.
• Kant’s epistemology puts the human mind at the centre of
knowledge(-making): the human observer is involved in the
universe.
• Hence, properties we assume belong to the world may be properties
of the human mind.
• Perception is an active process; the mind contributes to our
experience of reality; its properties can be studied empirically,
through introspection).
• By doing this Kant thinks he solves many of the problems of both
rationalism and empiricism.
• He offers a solution that unites the insights of each approach to the
world – ‘Transcendental Idealism’
Kant’s context: reaction to Hume
• Kant reads Hume as a young man and is shocked: “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.” ‘Prolegomena to any
Future Metaphysics’ (1783)
• Kant disagreed with Hume’s suggestion that humans are emotional,
not rational, beings, and that we should accept that reason is a very
limited tool at best.
• Nor could Kant abide Hume’s claim that, at best, science and
philosophy are games people play to have fun, rather than ways of
attaining truth.
• Kant disagreed with Hume’s argument that general concepts such
as those of causation and induction are simply habitually formed and
not really logically grounded.
More context: problems with Rationalism, and with
Empiricism
• Descartes’ problem, for Hume: reason as foundation of knowledge
leads to empty, formally correct statements, but which don’t seem
to have referents out in the world so aren’t much practical use
• Hume’s problem, for Kant (and Descartes): experience as
foundation of knowledge leads to useful statements, but these have
a messiness and uncertainty about them that isn’t desirable
• Kant agrees with empiricists that innate ideas are not viable.
• Yet problems with empiricism over the acquisition of certain abstract
concepts reopen the case for a priori knowledge.
• He offers a solution which tries to reconcile the two approaches to
the world: a formal system of a priori foundational principles for
knowledge.
A reminder of some basic terminology which Kant
invented…
• A posteriori knowledge - knowledge based on empirical facts and
hypothetical truths.
• A priori knowledge - knowledge of logical and transcendental
truths which isn’t based in particular experience.
• Analytic statement - a statement or item of knowledge known to be
true because of its conformity to rules of logic.
• Synthetic statement – a statement or item of knowledge that is
known to be true because of its connection with some intuition.
• Empirical, a posteriori sense experiences are essential for our ideas
of the world to have content. Messy but useful, basically.
• Analytical, a priori analytical structures are essential for unity,
cohesiveness, meaning of our ideas. Precise but bland, perhaps.
A key Kantian tool: Transcendental Deduction or
Argument
• Transcendental arguments are anti-skeptical arguments focusing on
the necessary enabling conditions
– either of coherent experience
– or of the possession of some kind of knowledge or cognitive ability…
• Transcendental arguments begin with some obvious fact about our
mental life, such as some aspect of our knowledge, our experience,
our beliefs, or our cognitive abilities
• and add a claim that some other state of affairs is a necessary
condition for the first one to exist e.g. where there’s smoke, there’s
fire…
• Kant uses Transcendental Arguments to identify the logically
necessary structural principles for the possibility of experience.
Kant’s Big Intuition: the Transcendental Deduction of
Space and Time
•
•
•
Kant asks: What are the necessary a priori conditions for perception?
Transcendental Argument: as we have perceptions, space and time must
exist. Representation occurs, hence space and time exist.
Because: perception = when we represent things to ourselves, and one
cannot represent events without saying WHERE and WHEN.
– SPACE: Not an objective, empirical property of the world. No empirical
perception can give us the idea of ‘space’. It is the subjective and logical
precondition for representation, a given.
– TIME: Not an empirical sensation, but a logical, a priori structuring principle. We
cannot represent phenomena without the notion of time, but we can represent
time empty of phenomena, therefore the idea of time is logically necessary and
prior.
•
•
Hence Space and time exist only as productions or structural elements of
the human mind, as "intuitions" by which perceptions are measured and
judged.
In addition to these intuitions, Kant proposed that a number of a priori
concepts, called categories, also exist.
What are the Kantian Categories?
• A built in, “hard-wired” capacity of the human mind by
which it organises and structures raw sense data
• the concepts which form the conditions of possibility of
human experience.
• The categories are a conceptual framework or
conceptual scheme in terms of which all objects of
empirical knowledge are analysed or filtered.
– Every perception is a two-fold reality: i) raw sense data and ii)
the organizing and structuring of that data by the mind.
– Sense data, in and of itself, is a meaningless jumble: everything
we experience is ‘filtered’ through the categories.
– If our knowledge were not filtered, we could not experience it; it
makes sense only after it has been organised and structured by
the mind’s categories.
– KEY QUOTE: ‘Concepts without intuitions are empty; intuitions
without concepts are blind.’
A descriptive analogy to help:
The Coin Sorting Machine
• Take a large bag of mixed coins of
different types. Is there £200 there,
or £25?
• While they remain mixed up in the
bag, the coins really have no value.
You cannot buy something with a
bag of coins without knowing its
value.
• Before you can spend the coins, you
have to sort them with a coin sorter
so that you know how much they are
worth.
• The coins don’t really have any true
value until they are sorted by the
coin sorter.
How does this analogy help?
• In this analogy, raw sense data is like the bag of mixed coins. In
itself, raw sense data is meaningless jumble.
• The coin sorter is analogous to the mind’s categories.
• The coin sorter provides organisation and structure and, thereby,
value to the bag of coins.
• The mind’s categories provide organisation and structure and,
thereby, meaning, to jumbled up, raw sense data.
• Write your own analogy…try the rules of chess and chess pieces,
glasses for a short-sighted person, containers for things contained…
Kant’s Categories
• There are four main categories, each divided into three subcategories. (HANDY TO KNOW THESE BY HEART…)
Quantity
Unity, plurality, totality
Quality
Reality, negation, limitation
Relation
Substance and accident, cause and
effect, reciprocity
Possibility, existence, necessity
Modality
The Categories are Synthetic A Priori ideas
Analytic
A priori
A posteriori
‘Triangles have three
sides’ (certain but dull)
(none – nothing. No truths
derived from experience are
tautological. )
Synthetic Kant’s Categories – a
short but important list
+ Mathematics (certain,
but also useful)
‘Triangles were the earliest
discovered geometrical
shapes’ (handy e.g. in a pub
quiz, but could be wrong)
• Synthetic a priori ideas have utter certainty, but can only be deduced after
experience. Experience lets you work out that you must have them (in order to
have experience), via a transcendental argument.
• Kant also sees mathematics as being composed of synthetic a priori
statements because it depends on the pure intuitions of the elements of time
and space. This is why maths has both a feeling of purity and certainty, yet
seems to be something that is discovered.
Why does this help with Hume’s scepticism about the
power of the human mind?
• For example, Hume had reasoned that, since it is neither a Relation
of Ideas (=analytic) nor a Matter of Fact (=synthetic), the idea of
causation as a universal constant is nonsense.
• Instead, Hume suggests that causation is just:
– co-occurrence of events, which leads to
– habitual association, which gives us the
– (Illusory) feeling of necessity
• Kant’s response: It’s true that causality is not a Relation of Ideas (a
logical idea) nor a Matter of Fact (one based on observation).
• But it is imposed by the structure of the human mind and so is
fundamental to science and human knowledge: it is a Category.
Kant’s response to Hume, in more detail: Causation is
a Category.
• Causation is neither a generalization from experience [a Matter of
Fact] nor an analytic truth [a Relation of Ideas], but, rather, a rule for
‘setting up’ our world…
• Like a rule in chess, Causation is not a move within the game but
one of the rules that defines the game...
• So too, for our belief in the ‘external’ or material world…this belief
is one of the rules that we use to constitute our experience
• The Categories are the ‘laws of experience.’
• Asking why the mind organises raw sense data using Causation, or
by any of the other categories, is exactly as silly as asking why a
criminal is put in jail.
• The answer, in both cases, is the same: “That’s the law.”
A consequence of Kant’s Transcendentalism: The
Noumenal World
• Transcendentalism: the philosophical view that there is a form of
knowledge derived from synthetic a priori judgements.
• Our knowledge of the world is mediated by the Categories. We only
know objects as we perceive them, as ideas.
• We can know that there are real objects, because we have
sensations of which these real objects are the necessary conditions
– they provide the raw material from which sensations are derived.
• Yet the world of the real objects cannot ever be known directly, so
we cannot know the real objects themselves.
• This world of real but extrasensory objects Kant calls the Noumenal
World, the world of 'things in themselves', the pure state of things’
being.
• Because the human mind structures the universe it perceives, we
can never perceive the raw data of experience, by defnition.
The Phenomenal World
• The world of perception, of subjective sense data after it has been
conditioned by space and time and organised and structured by the
mind’s categories, Kant calls the Phenomenal World.
• This is the world in which humans live and of which they have
knowledge.
• “[W]e indeed, rightly considering objects of sense as mere
appearances, confess, thereby, that [the appearances] are based
upon a thing in itself, though we know not this thing as it is in itself,
but only know its appearances, namely, the way in which our senses
are affected by this unknown something.” [Prolegomena to Any
Future Metaphysics]
• So we can only know the world as it appears to us, not as it is in
itself.
Some issues with Kant’s Conceptual Scheme and the division
between Noumena and Phenomena: Isolation, Solipsism…
• Order and structure do not exist “out there” in the noumenal world.
(For all humans know, the noumenal world might as well be
Heraclitus’s formless flux: 'Fire is in all things'.)
• Order and structure for humans exist only in the phenomenal world
of the human mind.
• Yet humans can have no knowledge of “things in themselves”. In a
way, we are forced into Kant’s conceptual scheme, cut off from the
real, the noumenal.
• And can we be sure that each human mind organises and structures
the raw sense data of the noumenal world in the same way, by
means of the same categories?
• Might it not be that each human being creates his/her own individual
and unique phenomenal world? We are all in prisons of our own
creation…
• Kant naturally asserts that all minds must of necessity use exactly
the same perceptual categories…
So: Kant in a nutshell
• Some problems of empiricism helped: he explains how we possess
highly abstract concepts, and places the human mind at the centre
of everything.
• A key notion of rationalism defended: we do have innate ideas, as
these innate formal structures are necessary conditions for
perception and explain perceptual coherence.
• Some problems of rationalism helped: the role of a priori knowledge
is clarified and the role of wholly certain statements explained.
• However: distance between perceiver and world entrenched.
• Phenomenal world seen through perceptual, cognitive structures
• Noumenal world: things in themselves inherently mysterious,
theoretically unknowable.
• Permanent veil of perception theoretically necessary.
• Key question, after Kant: “If these principles are grasped a priori,
then do they track the way the world is, or just articulate the way the
world is to me?”