Kant’s Transcendental Idealism and A Priori Knowledge
Transcendental Conception of A Priori
Transcendental conception of a priori
A priori knowledge, according to Kant’s theory, is defined as one that is completely independent of experience, not just independent of this or that experience, but of all experience.
Now, between a priori knowledge, those to which nothing empirical has been added are called pure. For example, the proposition every change has its cause is indeed a priori; it is independent of experience. However, it is not pure a priori, since the concept of change can only be derived from information provided by the sensitivity, and in this sense, it is an a priori proposition that has something empirical added to it.
A Priori
A priori forms of sensation, or pure intuition, as Kant calls them, and the categories or pure concepts of understanding, although dependent on sensory experience in order to have something on which to act as such, are completely independent of sensitive data; that is, a priori. However, one must admit that these forms should be universal and necessary. They do not depend on experience and cannot be challenged by any facts in the world. Consequently, they have to apply to all valid knowledge and all human beings (universality), while they are necessary regarding the understanding of the phenomena.
Kant’s Copernican Revolution in Philosophy
Kant explains the Copernican revolution, which is changing his philosophy on the conception of knowledge, based on an analogy with the Copernican revolution. In astronomy, Copernicus realized that he could not understand the motion of celestial objects with the view that the Earth is at the center of the universe and the sun and other celestial objects revolve around it. He realized that to understand the movement of celestial objects, it was necessary to change the relationship by putting the sun in the center and assuming that the Earth is spinning around.
Kant considered that philosophy should undergo a similar Copernican revolution. In philosophy, the problem is to explain synthetic a priori knowledge. The philosophy before Kant supposed that in the experience of knowing, the knower is passive; the object known influences the subject and provokes in him a faithful representation. With this explanation, we can understand, in any case, empirical knowledge, but not a priori knowledge, as the latter is special in that we can know some things before we experience them, that is, before they can influence our mind.
Kant proposes to reverse the relationship and accept that in cognitive experience, the knowing subject is active; in the act of knowing, the knower adjusts the known reality. According to Kant, we can understand synthetic a priori knowledge if we deny that we submit to things, if we accept that it is rather things that must be submitted to us. As an object to view, it first has to comply with the conditions of possibility of all possible experience, i.e., the formal – a priori – imposed by the structure of our cognitive faculties. We can know a priori any of the features that must have when it is present before us precisely the features that depend on these conditions.
For example, a priori, we cannot ever know if the figure that we will see on the chalkboard is a triangle, or the contingent features of that figure (such as its size, its concrete form, …), but we can know a priori that if it is a triangle, it has to possess all the properties described by geometry because, according to Kant, they are a consequence of the peculiar structure of our minds, and they must submit any object which can be experienced.
Kant summarizes these ideas with the following sentence: we can only know a priori of things that we have previously put into them.
In short, the Copernican revolution mentions the fact that we can only understand a priori knowledge if we admit that we only know phenomena and not things in themselves or noumena, if we admit Transcendental Idealism as the true philosophy.