Rationalism vs. Empirism?
Kant's intellectual development can be considered a remarkable summary of all the philosophy that precedes him, particularly empiricism and rationalism according to the approach of the philosophers of modernity.
rationalism postulates the possibility of knowledge through the only help of reason. For rationalism, a knowledge truly deserved by man, must be necessary and universal. But experience shows something different, since the knowledge it provides is neither necessary nor universal, but on the contrary, contingent and particular, therefore, for rationalism, empirical knowledge is not true but only that reason can reach by itself. The reason is, therefore, not the ability to achieve phenomena but reality (the ultimate background of things). This faculty would allow to know things like the existence of God, the immortality of soul or the infinitude of the world, etc. Empirism, on the other hand, postulates that the only legitimate knowledge is that which comes from experience in such a way that reason lacks competence beyond information provided by the senses.
Rationalism and empiricism are presented as essentially opposite theoretical approaches. Kant, will observe that despite this obvious confrontation, lies a coincidence in which its criticism will fundamentally affect: rationalism and empiricism are two forms of realism (theory that argues that for the act of knowing the determinant is the object - lat. res (thing) = realism-) The cognitive subject is comparable to a mirror in which things are reflected, this' mirror 'would be for rationalists reason and for empiricists, the senses, but in any of these cases, the scheme is basically the same. And so, while rationalists will say that what is done is to copy the ultimate foundation of things, empiricists will limit themselves to the phenomenal, the apparent, but in both cases, knowledge is reduced to a passive attitude on the part of the cognitive subject.
The gnoseological problem therefore consisted in determining whether the subject is only receptive as realism implies or whether, on the contrary, it is an action, a sort of praxis. Kant will be inclined to the idea of an active subject building the scope of objectivity. What does this mean? It means that the subject processes reality according to his possibilities. H.J.Paton proposes a comparison as an explanation: let us imagine for a moment that all human beings were born with blue lenses that filter that are part of our visual organ and suppose, moreover, that we were not aware of the filter that this organ assumes. Then we would believe, indeed that things are blue, that reality is bluish. In this way, knowing is not limited to reflecting reality but involves an operation on it for its subsequent transformation. This conception implies a turning point in the history of philosophy while for all thinkers before Kant knowledge was pure contemplation. Kant, revolutionarily, postulates that the subject performs a certain transformative operation on the object and elaborates it.
This approach leads us to consider that Kant is the antecedent of Hegel (which will conclude by stating that knowing is equivalent to creating the object of knowledge or reality itself) and that without Hegel, there would not have been Marx either.
In synthesis, Kant will observe that knowledge involves two factors:
The very structure of our reason that is independent of experience but that requires in order to be able to “transform” objects requires...
A modelable material: prints. ... neither concepts without intuition that somehow corresponds to them, nor intuition without concepts can give knowledge (because) thoughts without content are vations, intuitions without concepts are blind Kant, Critique of pure reason.
There is no doubt that all our knowledge begins with experience. For where would the faculty of knowing, for its exercise, be awakened, except through objects that hurt our senses and porvacate by themselves representations, or put in motion our intellectual capacity to compare, link or separate them and thus produce, with the raw material of sensitive impressions, a knowledge of objects called experience? Therefore, in the temporal order, no knowledge precedes experience in us and all knowledge begins with it. (...) But even though all our knowledge begins with experience, that is not why all of it originates from (from) experience. It may well be that our knowledge of experience is composed of what we perceive through impressions and what our own ability to know (on occasion only sensitive impressions) provides for itself. Criticism of pure reason, Kant
Indeed, according to Kant, for knowledge to be possible, it is necessary:
The structure of our 'reason', which is independent of experience
A modelable material, which the structure of reason will deal with elaborating: neither concepts without intuition that somehow corresponds to them, nor intuition without concepts can give knowledge (because) thoughts without contents are empty, intuitions without concepts are blind Critical to pure reason, Kant
In this way, the reason is composed of:
Pure forms of sensitivity (pure intuitions): space and time
Categories: Pure concepts of understanding such as substance, causality, unity, plurality...
According to this scheme, it is understood that space, time and categories are nothing but instruments or molds by which the subject elaborates the world of objects. The material input on which reason will activate will be the impressions or sensations, which are nothing but the content.
Kant will therefore state that if one tried to know using such only reason (i.e. the subject 'a priori' forms) one would only obtain empty forms, so knowledge of objects would not be possible. It is necessary that the 'instruments' have a material to mold. The origin of the moldable material will be none other than that of experience and in this sense, Kanto coincides with empiricism in that he maintains that consciousness is only possible within the conditions of experience so he will declare the impossibility of metaphysics since in order for it to be attainable, objects such as God, soul ( metaphysical objects) should be accessible to experience.
But despite this approach to empiricism, Kant observes that impressions alone do not make knowledge. Because these, without the forms imposed by rationalization (forms that cannot come from impressions but from the subject itself) are just chaos and disorder.