Summary: Critique of Pure Reason (page 9)

To answer this question, the mind must take itself as its own object of study, uncover how the understanding operates, and thus develop a distinct science—one that I call the critique of pure reason ¹.

This constitutes transcendental knowledge, in the specific sense Kant gives to the term:

I call transcendental all knowledge that concerns not so much objects themselves as our mode of knowing objects, insofar as this mode of knowledge must be possible a priori.

Transcendental philosophy is the discipline that takes as its object of study the entirety of our a priori concepts.

The transcendental critique is what must serve as the touchstone for determining the validity—or lack thereof—of all a priori knowledge. In this sense, it functions as a canon of knowledge, establishing or invalidating its legitimacy.

This science must be divided into two parts: a theory of the elements of pure reason, and a theory of method.

Having completed our reading of the Introduction, we are now ready—equipped with these explanations—to proceed to the first part: the Transcendental Theory of Elements.

Transcendental Theory of Elements

Transcendental Aesthetic

What does transcendental aesthetic mean? Once again, understanding the title represents a significant step towards understanding the chapter.

In the final lines of the Introduction, Kant draws a fundamental distinction between the two faculties that constitute our capacity for knowledge:

There are two sources of human knowledge, namely sensibility and understanding, through the former of which objects are given to us, while through the latter they are thought.

Here a new faculty appears: sensibility.

This distinction corresponds to an intuitive idea: we receive various sensations from the external world—a sensation of cold, a colour, a smell, and so on—which are then analysed by the intellect.

Kant's terminology, however, is precise: he does not speak of sensations received by our senses—which would give his analysis a largely biological character—but of intuitions provided by our sensibility. Likewise, he does not refer to ideas of the intellect but to concepts of the understanding.

It is this terminology that adds to the difficulty of the work and often discourages readers. Today, we use the terms intuition, sensibility, and aesthetic in quite different ways.

We now speak of intuition, for instance, as a kind of almost mystical premonition; sensibility and aesthetic belong to the artistic domain—we say that we are more or less sensitive to a painting or a piece of music, and aesthetics is the discipline that studies works of art.

These meanings, however, are entirely absent from Kant's use of these terms.

When Kant speaks of intuition, it is important to understand that he is referring to nothing other than sensations. He chooses a different term—most likely to avoid the biological connotation associated with the notion of sensation (Kant's reflection on the faculty of knowledge is not a physiological study of the anatomy of the eye, for instance). His is a different approach—transcendental, as we have seen—one that examines the a priori conditions of knowledge, and this difference in approach requires a specific terminology.

Similarly, sensibility and aesthetic had no artistic connotations in Kant's time. It was only later, following the work of philosophers such as Schiller and Hegel, that these terms acquired their modern artistic meaning.

We must therefore take these terms in the precise sense Kant assigns to them, bearing in mind that they are more accurate and better suited to the theory he wishes to develop.

Sensibility, as a passive faculty, is that through which objects are given to us in intuitions; the understanding is that through which they are thought by means of concepts.

Intuition and concept are complementary. Taken in isolation, neither can produce knowledge. Later, in the Introduction to the Transcendental Logic, Kant sums this up as follows:

Thoughts without content are empty; intuitions without concepts are blind.

We must begin by studying sensibility, as it comes first chronologically: an object is received before it is thought. As Kant states: The conditions under which objects of human knowledge are given must precede those under which the same objects are thought.

It is in the first paragraph of the Transcendental Aesthetic that this faculty is described.

¹ Our translation. The references for the quotations are available in the book Kant: A Close Reading