Kant’s Philosophy: Ethics, Future, and Metaphysics
Kant’s Categorical Imperative and Moral Action
What should I do? Instead of pursuing an end, Kant’s ethics focuses on the duty that dictates how we should act. Using a categorical imperative, which is universal, practical reason tells us how we should behave. A moral action is one guided by reason and good will, acting out of duty and respect for the moral law. According to Kant’s categorical imperative (an absolute and unconditional order), we should “act according to that maxim that you want to become, at the same time, a universal law” and “act so that you relate to humanity in your person, or in any other, always as an end and never as a means.”
Kant’s Vision of the Future: Three Purposes
What may I hope for? We can anticipate three “purposes” in the future:
- Happiness: If we behave morally, we can expect happiness, supplemented by a belief in God.
- Triumph of good over evil: Humans possess an “evil principle” that can lead them away from the moral law. However, we can hope for the triumph of moral motivation. This victory will be achieved when individuals live in an “ethical community,” a society governed by the laws of virtue.
- Perpetual peace: Peace is the ultimate goal of progress and history, the aim of the political system. If peace is achieved, it will be through law. Kant advocates for the creation of a federation of peoples and an international authority.
Kant’s Epistemology: Metaphysics as a Science
What can I know? Is Metaphysics a science? Arguments are relations between statements or judgments (attributing qualities to a subject). To determine if they are universally valid, we must examine if their judgments are extensive (expanding our knowledge) and universal (valid in all circumstances). There are several types of judgments:
- Analytical: These are not extensive; the predicate is contained within the subject.
- Synthetic: These are extensive and broaden our knowledge.
- A priori: These are independent of experience.
- A posteriori: These depend on experience.
To establish science, we need a priori synthetic judgments. Hume argued that we must seek truth in nature, and Newton demonstrated that physics is a priori, not solely based on experience. Theoretical physicists formulate a priori hypotheses.
Sensitivity and Understanding
All knowledge begins with experience. The first step is sensitivity, the ability to receive sensory representations of objects through the senses. These representations are called sensible intuitions. Sensory representations can have matter (sensory data) and form (obtained by pure intuition of space and time). Sensitivity depends on our senses and mental structures, which both enable and limit us. We structure everything in space and time, which are a priori forms of sensibility. The phenomenon is the set of sensations in space and time. We can only know something if the phenomenon is given; God is noumenal, a thing in itself, but we cannot know God directly because we lack a phenomenon of God.
A Priori Judgments in Mathematics and Physics
Are synthetic a priori judgments possible in mathematics? Mathematical knowledge is a priori because arithmetic requires understanding time, and geometry requires understanding space. Understanding is the capacity to unify phenomena under concepts. There are two types of concepts:
- Empirical: These come from sensory experience. After observing and comparing common characteristics, we extract and form concepts.
- A priori: These categories are spontaneous creations of understanding that serve to group and organize the intuitions of sensibility. These include quantity (unity, particularity, totality), quality (affirmation, negation, limitation), relation (accident, cause, reciprocal action), and modality (necessity, evidence, contingency).
Are synthetic a priori judgments possible in physics? All physical knowledge is knowledge of phenomena to which the categories are applied.