January/February 2015

Kant made simple

Written by Matt McCormick

Immanuel Kant (1724 - 1804) was a German philosopher who taught for many years at the University of Koenigsberg. He made pivotal contributions to the study of ethics and epistemology and was a leading figure in the German Enlightenment.

Two stages of knowledge


Kant identified two stages in the process whereby our mind works the raw material of sensation into the finished product of thought. The first stage is the coordination of sensations by applying to them the forms of perception - space and time. The second stage is the coordination of perceptions by applying to them the forms of conception - the categories of thought.

— Stage 01 —
A sensation is merely the awareness of a stimulus, such as a taste on the tongue, pressure on the hand, or a flash of light in the eye. These scattered sensations do not constitute knowledge. They are all that the infant has in the early stages of its development, before it recognises objects. The mind groups the various sensations about an object, such as an apple. The sensations of odour, pressure, light and taste are united to constitute a "thing", which we call an apple. There is now an awareness not so much of a stimulus as of a specific object. This is what Kant means by a perception.

The process by which the scattered sensations came to be ordered into a perception is not a property of sensations themselves but relies on the activity of the mind. Firstly, not all the sensations are accepted; most are ignored. Myriad forces play upon our bodies at any moment, causing a storm of stimuli, yet only those selected can be moulded into perceptions suited to our present purpose, or that bring messages of danger. The clock is ticking and we do not hear it; but that same ticking, no louder than before, will be heard at once if we listen for it.

Kant believed that the mind uses two primary methods for the classification of the material presented to it: the sense of space, and the sense of time. Space and time are not things perceived but modes of perception, ways of putting sense into sensation. Space and time are apriori because all experience presupposes them. It is inconceivable that we should have any future experience that will not involve them. We never see empty space, only objects and background. We infer that there is ‘empty' space between objects, but we do not see it.

— Stage 2 —


In the second stage, the mind raises the perceptual knowledge of objects into the conceptual knowledge of relationships, sequences and laws. Just as the mind arranged sensations around objects in space and time, so in the second stage the mind arranges perceptions (objects and events) about certain basic ideas. According to Kant these are: unity, plurality, totality, reality, negation, limitation, substance-and-accident, cause-and-effect, reciprocity, possibility, necessity, and contingency.

These are Kant's famous twelve categories. They are subjective in the same sense in which space and time are, i.e. our mental constitution is such that they are applicable to whatever we experience, i.e. they are the means by which we process our experience. Yet there is no reason to suppose them applicable to things-in-themselves. The categories are the pre-existing structures in the mind into which perceptions are received, and by which they are classified and moulded into the ordered concepts of thought. Objects serve as the building blocks of all our thinking and knowing. The categories are the bridge to the ideas that we have of the world. All our understanding, all theory is mediated by them.

Summing up


Sensation is unorganised stimulus, perception is organised sensation, conception is organised perception, i.e. knowledge. At the next level, science is organised knowledge. At each stage there is a greater degree of order and unity. This unity cannot come from thingsin- themselves, for these are known to us only as bare sensations. It is our mind that imposes order, sequence and unity onto raw experience. The world does not have order of itself, but because thought creates it

The world as we know it is a construction, a product to which the mind contributes as much by its molding as things-in-themselves contribute through stimuli. (We perceive the building as rectangular, whereas we see a trapezium.) Kant wrote, "It remains completely unknown to us what objects may be in themselves and apart from the receptivity of our senses. We know nothing but our manner of perceiving them." The moon as known to us, is merely a bundle of sensations, unified by our native mental structure through the elaboration of sensations into perceptions, and of these into conceptions or ideas. As a result, the moon is for us merely our ideas.

Kant does not doubt the existence of the external world; he merely asserts that we know nothing about it except that it exists. A goodly part of every object is created by the forms of perception and understanding. We know the object as it manifests in our mind; what it is before being moulded by our mind we cannot know.

By Matt McCormick:http://soler7.com/IFAQ/Kant.html Professor McCormick is a past winner of the Outstanding Teaching Award for the College of Arts and Letters.