Kant’s Transcendental Idealism: A Deep Dive
Theory of Sensitivity: The Transcendental Aesthetic
Kant addressed the first faculty of reason, the power to sense perceptions, in the Transcendental Aesthetic. All knowledge, according to Kant, is a synthesis between matter and form. Matter is the content, and form is what the transcendental subject imposes. Matter and form make scientific knowledge possible.
Sensible Knowledge
Sensible knowledge is a synthesis between sensations and the a priori forms of sensibility: space and time.
Synthetic A Priori Judgments in Mathematics
Kant relates mathematics to sensible knowledge, explaining this reasoning as follows:
- Geometry and arithmetic deal with space and time, respectively.
- The judgments of mathematics predate experience; both are universal and necessary.
- They are also synthetic.
Analysis of Understanding: The Transcendental Analytic
Intellectual Knowledge
The function of understanding, according to Kant, is to understand empirical intuitions. With sensible knowledge, we perceive a variety of individual objects in space and time, but we do not understand them or know what they are because they lack unity. Kant considered categories to be necessary conditions for understanding empirical phenomena. Thus, intellectual knowledge is the result of a second synthesis: between sensible intuitions in space and time (given by the sensitivity of the subject) and categories (set by the understanding, its form).
Synthetic A Priori Judgments in Physics
These judgments are a priori, and therefore universal and necessary, because they utilize a priori categories. They are also synthetic. These judgments of physics are based on the category of cause and effect.
Phenomenon and Noumenon
The phenomenon is the thing *for me*, what appears to the knowing subject. The noumenon, rather, is the thing *in itself*, the object as known beyond its relationship with sensibility. Kantian philosophy is a transcendental idealism.
Role of Reason: The Transcendental Dialectic
Kant studies reason as the power to make arguments in the Transcendental Dialectic.
The Transcendental Ideas of Reason
Reason seeks general judgments that serve as a basis for other, more particular judgments. Reason tends to seek universal judgments, thus crossing the barrier of experience. Transcendental ideas, according to Kant, are produced when reason tries to know the thing in itself. These ideas correspond to the three objects of rationalist metaphysics: the self, the world, and God. Kant called the transcendental idea of God a *pure idea of reason* and stated that it is impossible to prove its existence or nonexistence.
Practical Knowledge and Morality
Moral Conscience and Goodwill
Conscience is an internal activity that provides humans with principles of conduct and judges whether their actions are good or bad, freely. Moral conscience presupposes freedom and will, which is the power every rational being has to propose moral law to itself. Therefore, only the will can be classified as good or bad from a moral perspective.
Duty and the Categorical Imperative
The criterion to determine whether a will is good lies in what *should be*, which comes from practical reason. For Kant, the good will can be of two types:
- Will that acts according to duty, but from inclination.
- Will that acts according to duty *and for duty’s sake* (only this makes it good).
Kant defined duty as the necessity of an action out of respect for the law, a mandate expressed in the form of an imperative. There are two kinds of imperatives:
- Hypothetical: These determine the will as a means to an end different from that duty.
- Categorical: These determine the will without any condition, because it is an end in itself.