Critique of Pure Reason and Moral Philosophy
Critique of Pure Reason
2.1 The Problem of Metaphysics
Critique of Pure Reason deals with knowledge and theoretical philosophy. The problem of unquestioned metaphysics arises against the possibility of sciences. Reason appears indifferent to the objects of these themes. Kant observes a natural tendency of reason to question itself. The key point is the validity of unquestioned science. It is a fact, but how is it possible after unknowingly engaging with metaphysics?
2.2 Kantian Conception of Knowledge
2.2.1 Empirical and A Priori Knowledge
All knowledge begins with experience, but not all impressions matter for knowledge. Our cognitive faculty plays a role. Empirical knowledge is a posteriori, while knowledge from our faculty is a priori. Referencing Hume, necessity and universality come by the faculty of knowledge. The investigation of a priori elements is called transcendental a priori.
2.2.2 Copernican Revolution in Knowledge
The object does not modify the subject, but the subject modifies the object. This doesn’t mean the object is created by the subject. Rather, the subject forms the object according to its way of viewing. This subject-object relationship involves phenomena and noumena.
2.3 Synthetic A Priori Judgments
How is science possible? Analytical judgments are preached in the concept (explanation), while synthetic judgments expand beyond the concept (amplification). Synthetic a priori judgments connect subject and predicate, are universal and necessary, and expand knowledge.
2.4 Structuring the Problem in KRV
- Transcendental Aesthetic: Synthesis of empirical and a priori.
- Transcendental Analytic: Synthesis of experience at the level of understanding. Possible synthetic a priori judgments in physics.
- Transcendental Dialectic: Study of reason. Results from the Transcendental Aesthetic.
2.5 Transcendental Metaphysics
Kant calls sensitivity the ability of a subject to be affected by external reality. Sensations are the effects of objects, given a posteriori, and are matter of knowledge. The level of form is a priori sensibility, which is in the spirit. We perceive things ordered by space-time, which are the conditions of possibility of experience and a priori forms of sensibility. Space relates to geometry, and time to arithmetic.
2.6 Transcendental Analytic
Knowledge results from cooperation between sensibility and the rules of understanding. If aesthetic sensibility is the form, the law of understanding is logical. Kant divides transcendental logic into analytic truth and the logic of dialectics (logic of appearance), which are the foundation of physics.
2.7 Transcendental Dialectic
This section addresses the broader problem of understanding and metaphysics. It is not a negative critique of metaphysics. Three main ideas are:
- Soul (thinking subject): Permanent substance.
- World: Concatenation of phenomena.
- God (comprehensive causal): First condition of possibility of all being.
These constitute psychology, cosmology, and theology, respectively, in Wolff’s metaphysics. Kant doesn’t deny these concepts but questions their role in knowledge.
- Rational Psychology: Based on the self as a permanent substance. Kant calls its arguments based on “fallacy.”
- Cosmology: Falls into antinomies, where contradictory propositions can be shown with equal truth.
- Theology: All proofs are fallacious.
That the science of the soul, world, and God are dialectical doesn’t mean that the science of reason is dialectical. These ideas are useful as practical ideas, which Kant calls “governing ideas.”
3. Moral Philosophy
Pure reason and practical reason are not two different reasons, but two uses of the same reason: theoretical and moral.
3.1 The Problem of Morality
The goal is to find the foundation of morality and the principles for judging an action as morally right or wrong. Moral judgments carry duty, an obligation not from society but a priori. Moral judgments are universal and necessary, regardless of experience.
3.2 The Concept of Good Will
Kant begins Groundwork of the Metaphysics of Morals with the concept of good will. A good will is good in itself. He distinguishes between acting according to duty and acting from duty. True moral action must be from duty.
3.3 Moral Law
One should always act so that their behavior could become universal law. Moral concepts originate in a priori reason. The moral law is formal because it is a priori.
3.4 Imperatives
Two types of imperatives exist: hypothetical and categorical. Hypothetical imperatives see action as necessary to achieve a purpose. Categorical imperatives…
3.5 Autonomy
The will is autonomous when it chooses to follow behaviors based on universal laws. It is not subject to any law other than the one it gives itself. The opposite is a heteronomous will.
3.6 Postulates of Practical Reason
These postulates are freedom, immortality, and the existence of God. Freedom is negatively defined as the capacity to act freely, and positively as the capacity to act according to laws other than those given by nature. Man is both phenomenon and noumenon.