Kant's Philosophy: Understanding, Reason, and Transcendental Ideas

Categories: Unifying Intuitions of Sensibility

Which is a category? All knowledge is to judge, that is, to unify the intuitions of sensibility by means of pure concepts or categories. Categories are the possibilities we have to make claims about what has not affected us. According to Kant, the understanding is capable of making judgments in 12 different ways, and if we are able to do this, it is because, a priori, without obtaining the experience, we have twelve categories or ways to meet phenomenal reality. Kant insists that we know reality itself, that the categories are the way the world is comprehensible to humans. Among the most important categories is that of causality. The categories allow us to make judgments about the physical world and make possible empirical science.

Reason as the Supreme Power of Knowledge

Define reason as the supreme power of knowledge. In the last part of the Critique of Pure Reason, "Transcendental Dialectic," Kant addresses the third of the powers of knowledge: reason. Reason completes the process of unifying the knowledge gained. Reason is, therefore, the supreme unifying power of knowledge. It tends to unify phenomenal reality in concepts, increasingly general and abstract, until it reaches the first principles that are not subject to any preconditions. Its function is to reduce the enormous range of knowledge to the smallest number of principles. The principles of reason are not provided early, but initial conditions which are unconditional.

Ideals of Reason: Soul, World, and God

Which are the ideals of reason? These unconditioned principles are called by Kant "ideas" and "ideals of reason." They are not judgments or propositions, but a priori concepts, which he also calls "pure concepts of reason" or "transcendental ideas." Kant distinguishes three:

• The soul or self: The ideal of reason that unifies all the phenomena of inner experience.
• The world: The ideal of reason that unifies all the phenomena of external experience.
• God: The ideal of reason that integrates the absolute unity of all phenomena.

The ideas of soul, world, and God unify all the phenomena that the understanding structures by categories. These ideas lead us to believe all phenomena in a unified fashion, but shed no light on the whole. This lack of empirical support is the reason why metaphysics cannot be considered as a science.

Transcendental Illusion: Limits of Metaphysics

What is the transcendental illusion? Categories can only be applied to the material provided by experience, and this is not the case with concepts such as soul, world, or God. The ideals of reason are tools to unify knowledge; they are guiding principles of knowledge, and in this sense, they are indispensable. When metaphysics doubts this regularity and considers the soul, world, and God as objects given by sensitivity, on which we can use categories such as cause and substance, it falls into the transcendental illusion. This explains why science progresses, but not philosophy.