Kant's Critique of Pure Reason: Conditions of Science

The Conditions of Possibility of Science

The problem is, can metaphysics become a science? It would require that metaphysics fulfill the same conditions that both existing sciences, mathematics and physics, meet. For a trial to be regarded as scientific, it must meet two conditions: increasing our knowledge and possessing necessary and universal validity. A trial to increase our knowledge has to be a synthetic view, and the character of necessity and universality could not come from experience. Experience only provides contingent truths of fact and individuals. That is, the necessity and universality of a trial can only be established outside of experience, or a priori. In conclusion, scientific judgments must be synthetic a priori judgments.

• An analytical view: a view such that the predicate B is already included in the subject A (analytic judgments do not increase our knowledge).
• A synthetic view is a view such that the predicate B is not included in the concept of subject A (increase our knowledge).

Synthetic judgments are based:

• A posteriori, relying on experience.
• A priori: independent of experience (and only then it may be necessary and universal).

The claim that all scientific opinion must be synthetic a priori is a novelty introduced by Kant. This is the problem that the Critique of Pure Reason arises: How are synthetic judgments possible a priori in mathematics and physics? Is metaphysics possible?

Criticism of the Authority of Knowledge

If we are able to build a priori synthetic judgments, it is because not all our knowledge comes from experience. There must be something that makes our judgments independent of it. The task of the Critique of Pure Reason is to discover those elements, non-empirical or a priori, and justify their use. Kant now attempts some synthesis between rationalism and empiricism. Although all our knowledge begins with experience, not all of it comes from experience.

Indeed, it may be that our empirical knowledge is a composite of what we receive through impressions and of what our faculty of knowing causes (caused by impressions) from itself. The understanding does not start to think for itself; something must be given from the outside to start its operation. First, we are open: we receive sensations. Thanks to them, we have an immediate relationship with an object through the senses (empirical intuition). But something else is set by the knowable subject: that something more being added is an a priori. So the relationship between what is given by the senses and the act of knowing is a relationship that Kant called matter and form. So the explanation of knowledge in Kant has something of empiricism (the subject of knowledge is empirically given) and some of rationalism (the form is set by the subject, therefore, is something a priori. Therefore, in order that we know, it comes from the development of the empirical material provided to us by the senses or cognitive structures forms the subject. In conclusion, the object known to us is the product of an addition of matter and form of empirical data and a priori forms of the given and put.

• Just because we know a priori forms that organize the chaotic material of sense impressions. These forms or cognitive structures are the subjective conditions that make possible our knowledge of reality.

Kant is at a point of view he calls transcendental: he analyzes the knowledge itself to discover there the a priori conditions that make it possible. A priori forms are independent forms of experience.

• The so-called Copernican revolution is explained as follows: we only know a priori of things that we ourselves have placed on them. The a priori is provided to the subject.