A philosophical view that distinguishes between the world as it appears to us (phenomena) and the world as it is in itself (noumena). It argues that our knowledge is limited to the realm of appearances, which are shaped by our own mental faculties.

The supreme principle of morality, which states that one should act only according to that maxim (rule) that one can will to become a universal law. It emphasizes the importance of acting out of duty and respect for moral law.

Things-in-themselves, or the world as it exists independently of our perception and understanding. Noumena are unknowable to us, as our knowledge is limited to the realm of phenomena.

The appearances of things as they are perceived and understood by our minds. Phenomena are shaped by our own mental faculties, such as space, time, and the categories of understanding.

Knowledge that is independent of experience and derived from reason alone. It is universal and necessary, as opposed to a posteriori knowledge, which is based on empirical observation.

Knowledge that is derived from experience and empirical observation. It is contingent and particular, as opposed to a priori knowledge, which is independent of experience.

Judgments that are both informative (synthetic) and independent of experience (a priori). They provide new knowledge about the world that cannot be derived from mere analysis of concepts. Examples include mathematical truths and the principles of causality.

The faculty of reason that operates independently of experience and is concerned with the a priori principles of understanding and knowledge.

The faculty of reason that is concerned with moral action and the will. It is guided by the categorical imperative and seeks to act in accordance with moral law.

A universal and objective principle that governs moral action. It is expressed in the categorical imperative and is based on the idea of acting out of duty and respect for the dignity of rational beings.

The capacity of rational beings to act in accordance with self-given laws, rather than being determined by external forces or desires. It is the basis of moral responsibility and freedom.

An intellectual movement that emphasized the use of reason and critical thinking to challenge traditional authority and dogmas. Kant's famous motto for the Enlightenment is "Sapere aude!" (Dare to know!).