Kant’s Critique of Pure Reason: Metaphysics, Reason, and Morality
In this text, Kant sets out his proposal to solve a methodological problem that is the basis of metaphysics, aiming for it to become a science. He refers to traditional metaphysics, which handles concepts like God and the soul, which are outside all possible experience. Compared to other sciences like mathematics, Kant sees that the solution to the problem must be the imitation of metaphysics and a methodological turn, as both sciences have advanced since their revolutions in method. In this situation, Kant poses the critical method, intending to critique reason to discover the principles, laws, and ultimate goals that reason imposes upon itself. It deals with the possibility of any science in general and of metaphysics.
The Transcendental Dialectic deals with the possibility of metaphysics, as well as the nature and operation of Reason. There are two uses of the term Reason for Kant: certain knowledge and the ability to proceed using mere concepts, which will be criticized in this section. For Kant, human thought has an irresistible tendency to go beyond experience, leading the human mind to fall into error. Kant called the dialectic of these errors and illusions of reason and the critical study of them. Reason is not a faculty of knowledge but the supreme power of the unification of knowledge. Knowledge of understanding refers to something first and unconditional. Kant calls it the faculty of principles. Such initial conditions are called pure ideas or concepts of reason.
From the three types of syllogism: categorical, hypothetical, and disjunctive, Kant obtains the three ideas of pure reason: soul, world, and God. They are the specific objects of the three traditional parts of the metaphysics of Wolff (Psychology, Cosmology, and Theology). These ideas can unify all our knowledge of phenomena. All our knowledge about the phenomena of inner experience is unified by the idea of the soul; the best of our knowledge about the phenomena of external experience is unified by the idea of the world; and finally, the idea of God serves as absolute unity and supreme condition for all objects of thought generally.
Using these ideas, we think about the totality of phenomena, but we cannot know the reality of the soul, the world, or God because we do not have any intuition of such realities. The ideas are pure concepts without reference to reality. We cannot assume they represent things in themselves. They can only be used to unify the knowledge of understanding.
They have a regulative use for research in the phenomenal world in two ways: positively, they become ideals that drive us to broaden and not to restrain investigation, and negatively, they point out the limits that cannot be transgressed.
The conclusions concerning the soul, Kant calls the dialectical paralogisms of Pure Reason. The ‘I think’ is part of transforming it into ontological unity. ‘I think’ applies to the category of substance in the wrong way because it is not an empirical object. The dialectical conclusions about the world are the antinomies of reason. The thesis of each antinomy reflects the dogmatic positions of the world, while the antithesis reflects the empiricist position. The most famous is the third antinomy, freedom, because it is important not only for speculative thought about nature but also for practical reasoning, moral and religious. Thesis: There is freedom, and Antithesis: There is no freedom; only the laws of nature determine events.
The fourth antinomy leads to the question of God, the idea that there is a condition of all conditions (Thesis: There is a necessary being as the cause of the world; Antithesis: There is no such being). The dialectical conclusions concerning God are the Ideal of Pure Reason (all-encompassing fullness). It is the absolutely unconditioned condition while encompassing all things. It is the ultimate ideal of reason. There have been several attempts to prove its existence (ontological proof, cosmological proof, and theological proof.)
Thus, for Kant, all knowledge is knowledge of phenomena, while those realities that cannot be experienced, i.e., noumena, are beyond the realm of science. However, it appears that the three traditional objects of study in Metaphysics (soul, world, and God) are noumena. So, according to the conclusion above, metaphysics cannot be a science since these objects are not given in experience. Thus, Kant denies that we can have any scientific knowledge of these three realities, denying that metaphysics can become a science. Consequently, the Critique of Pure Reason shows a negative consequence for Metaphysics, as it limits its claims to absolute knowledge. However, this limitation is positive for reason in its practical and moral aspects, posing these ideas as necessary and fundamental tenets. Thus, we can say that true morality is Kantian metaphysics since it requires three factors: the existence of freedom, the immortality of the soul, and the existence of God.
One of the main results of the Critique of Pure Reason is precisely to enable theoretical reason (science) and practical reason (morality) not to invade each other and to allow the latter to occupy the place it deserves. Thus, the Critique of Pure Reason prepares the way for the next work, the Critique of Practical Reason.