Kant: main concepts & theory
Sensibility: Passive faculty which receives representations through the affection of objects on
the senses. Represents the world through singular intuitions. capacity to receive sensory
information through the senses.
Understanding: Represents the world through general ‘concepts’ faculty that allows us to
form concepts and make judgements about the external world.
Active faculty, job is to think, applying concepts to the objects given through sensibility,
combining data of the senses into judgements.
Imagination: mediates between sensibility and understanding and is responsible for
intuitions in such a way that the understanding can apply concepts to it.
= faculty for representing an object even without its presence in intuition.
Belongs to sensibility because it can give to the concepts of the understanding a
corresponding intuition.
Belongs to the understanding because its synthesis is an exercise of spontaneity, and it can
determine the form of sense a priori.
Reason: faculty that operates indecently from the senses and combines the judgement of
the understanding in a coherent systematic whole.
Phenomenal world: world that we have access to, how we perceive the world, through
space and time.
Noumenal world: world that we do not have access to, so the ‘real world’. Things in
themselves. Noumenal world is neither spacial nor temporal. We cannot know anything
about the noumenal world.
Noumenal world contains the things of traditional metaphysics, like God, whether there is
free will, causation, these are things we cannot know anything about, since we only have
limited knowledge through space and time, so only knowledge of the phenomenal world.
The human mind supplies necessary principles of sensibility (perception) and understanding
(conception).
If human minds try to extend the fundamental concepts and principles of thought beyond
the limits of perception for purposes of theoretical knowledge, it yields only illusion (illusion,
since we cannot know anything of the noumenal world, so imagining things beyond our
knowledge). are boundaries to our perception, imagining things beyond our knowledge,
about the noumenal world, can never lead to objective knowledge, since we cannot know
anything of the noumenal world since we cannot get any information about the things in
themselves.
Intuition
1. Pure intuition: a priori, representations of space and time. = universal.
2. Empirical intuition: intuitions are a posteriori representation of specific
empirical objects. = subjective, particular.
,Concept
1. Pure concepts: a priori representations that characterize the most basic structure of
the mind (categories).
2. Empirical concepts: a posteriori representation formed on the basis of sensory
experience of the world.
Transcendental: condition for the possibility of experience.
Transcendental idealism: theory that it is a condition of the possibility of experience that the
objects of experience are in some way mind dependent. = cannot have experience that is not
mind dependent, since our experiences are ordered through the concepts in our mind, like
the pure intuitions (space & time) and the pure concepts of understanding (categories).
The objects of our experience are mind-dependent, since they can only become known to
us within the concepts of space and time and are ordered because of categories.
Analytic: predicate is implicitly or explicitly given within the subject: e.g. Circle is round, no
new information given in an analytic statement.
Synthetic: predicate is not given within the subject, contains new information about
something, which cannot be known by analyzing it: e.g. Circle is blue, some bodies are heavy.
A priori: known to be true independently of experience, or at least any particular experience.
A posteriori: known to be true only on the basis of antecedent experience and observation.
Synthetic a priori not possible according to Hume.
Kant tries to show that synthetic a priori knowledge is possible. This is knowledge that is true
independent of experience but does give new information about an object/ concept.
Example of synthetic a priori: mathematics, logic, metaphysics (this last one is what he wants
to prove).
Mathematical example:
2 + 4 = 6.
Within the concepts of the numbers 2 and 4, it is not contained that 2 + 4 = 6. However, no
experience is needed to get to know this, it can be analyzed without sensory perception. So,
this is synthetic information (since it gives new information), but without sensory perception,
so a priori.
Other example: a straight line is the shortest distance between two points (from the
definition of a straight line, it does not contain the quantitative aspect of being the shortest
distance, but it can become known without the need of sensory information).
Example from geometry:
In your mind, you can think of a triangle. By analyzing the triangle, you can realize that the
angles add up to 180 degrees. This is true for all triangles. Without the need of sensory
experience, you can realize that the geometrical law is universal for all triangles, so with only
intuition, this can be universal.
Space and time:
Forms of appearance, they precede the appearance themselves.
, Sensation: matter of appearance.
Space and time are concepts within the mind of the observer, they are not given within the
objects themselves. Space and time are something our minds add on to the noumenal world,
to perceive it. This is why we cannot know anything about the noumenal world.
Space:
Not an empirical concept that has been drawn from outer experiences. Space is a necessary
condition, which is the ground of all other intuitions. Certainty of geometrical principles and
the possibility of their a priori construction are grounded in this a priori necessity.
Space is a pure intuition.
Space is represented as an infinite given magnitude.
Time:
Time is not an empirical concept that is drawn from an experience. Time is a necessary
representation that grounds all intuitions. One cannot remove time from experience. This a
priori necessity grounds the possibility of apodictic (= certain) principles of the relations of
time or magnitude in general.
Time is a pure form of sensible intuition.
Time is real within observer.
Space & time are two sources of cognition, from which different synthetic cognitions can be
drawn a priori.
Space is nothing other than merely the form of all appearances of outer sense, the subjective
condition of sensibility under which alone outer intuition is possible for.
Time is nothing other than the form of inner sense, of the intuition of our self and our inner
state. Time determines the relation of representations in our inner state.
Space = outer sense.
Time = inner sense.
Empirical intuition provides qualities such as colour, hardness, taste, temperature (matter).
Pure intuition provides the extension, place, impenetrability and shape (form).
we can think of a shape we have never seen before, without seeing it within nature first.
Thinking of a colour we have never seen before is however impossible, so this is empirical
intuition, whereas shape is part of pure intuition.
Space and time are in themselves objective. They are universal since we all have them &
organize them in the same way. This is a priori, before experience.
Transcendental philosophy is not idealism, since according to Kant, we assume things exist,
but how do we know?
Different than e.g. Berkeley (we have no knowledge of the world outside of us, it does not
exist, only within our perception).
For Kant, we do not have any knowledge of the noumenal world, only have access to
limited things within our perception (the phenomenal world), which is ordered within space
and time and the categories. Our mind influences the way we have perception, so we only
have information about the phenomenal world.
