Kant’s Philosophy: Understanding, Phenomena, and Metaphysics
Kant’s Philosophy: Understanding and Synthetic Judgments
Analytical Kant: Understanding and Synthetic Judgments
In his analytical work, Kant addresses two key issues: the nature of understanding and the possibility of synthetic judgments a priori in physics. The first question is addressed through two statements:
- Understanding phenomena involves applying known concepts.
- Pure concepts can only be validly applied to phenomena.
This clarifies Kant’s position relative to empiricism and rationalism:
- Against empiricism: Kant asserts that elements of knowledge are a priori, not derived from experience, and are the foundation of the universality and necessity of scientific knowledge.
- Against rationalism: Kant argues that such a priori concepts cannot be applied beyond experience, but only to phenomena.
Synthetic Judgments A Priori in Physics
Physics, while more “empirical” than mathematics, still relies on universal principles that transcend “real-life experiences.” Physics formulates laws based on experiences with real objects, as exemplified by Galileo and Newton. Experience, being multiple, varied, particular, and contingent, acquires universality and necessity through categories or pure concepts, such as the concept of cause and necessary connection.
In synthetic judgments a priori in physics, the category of cause is the form, and the phenomena are the matter. They are a priori due to the category of cause and synthetic because of the phenomena.
Phenomenon, Noumenon, and the Limits of Knowledge
The Legitimate Use of Categories
According to Kant, categories can be applied to phenomena. Things in themselves, which Kant termed “noumenon,” cannot be known and mark the limit of our knowledge. They are inherently unknowable.
The Copernican Revolution in Philosophy
Kant’s “Copernican revolution” in philosophy mirrors Copernicus’s heliocentric model. Instead of knowledge conforming to the object, it is the object that conforms to the cognitive structure of the subject. This shift in perspective, analogous to the astronomical revolution, posits that the Earth revolves around the Sun, not vice versa. [Cf. Foreword to the 2nd ed. Critique of Pure Reason, ยง 11-12]
In essence, knowledge is possible because the a priori forms of space and time sensitivity, along with pure a priori concepts or categories, are not objective features of things but a priori structures of the subject that enable knowledge. Knowledge originates from the subject, not the object.
The Impossibility of Metaphysics as a Science
Kant does not deny the existence of metaphysical ideas but only the possibility of scientific knowledge of them through theoretical reason. The reasons are straightforward:
- Kant’s metaphysics addresses the world as a whole (cosmology), the soul (psychology), and God (theodicy), aligning with Wolff’s classification and coinciding with the three Cartesian metaphysical substances.
- However, synthetic a priori judgments about these objects are impossible because there can be no sense impressions of them. This is evident for the soul and God. Similarly, we cannot have a sense impression of the world as a whole (we perceive parts of the universe, not the entirety).
- Since the soul, world, and God are not phenomena, understanding cannot apply pure concepts or categories to them, meaning they cannot be known. Pure concepts, in Kant’s view, can only be applied to phenomena and are not applicable to these objects because they are not given in experience.
In conclusion, a priori synthetic judgments are constructed by applying categories to phenomena. Since metaphysical objects do not fit this framework, there can be no scientific judgments about them, rendering metaphysics as a science impossible.
Theoretical and Practical Uses of Reason
Given the impossibility of metaphysics as a science, Kant addresses whether there is another way for reason to respond to its natural inclination towards the unconditioned. His answer is affirmative: the practical use of reason.
The critique of metaphysics has a positive implication: precisely because God and the soul are not phenomena, they may exist and be accessible as postulates of practical reason. We will now delve into Kantian morality, exploring reason in its practical application.