Practical reason in the context of Optics

The modern division of philosophy into theoretical philosophy and practical philosophy has its origin in Aristotle's categories of natural philosophy and moral philosophy. The one has theory for its object, and the other practice.

Practical philosophy concerns itself mainly with subjects that have applications in life, like the study of values, norms, politics, art, etc. The modern division of philosophy into theoretical philosophy and practical philosophy has its origin in Aristotle's categories of natural and moral philosophy. The one has theory for its object, and the other practice.

In philosophy and argumentation, a reason is a consideration that counts in favor of a conclusion, action, attitude or fact, or that explains why something is so. Reasons typically answer a why? question and are often introduced by expressions such as because, since, as, in virtue of, or in order to. They are central to accounts of practical reason, epistemic justification, moral evaluation, and everyday explanation, and they figure prominently in law and deliberative discourse.

Philosophers commonly distinguish three roles for reasons. Normative (or justifying) reasons are considerations that count in favor of responding one way rather than another (e.g., that it is raining is a reason to take an umbrella). Motivating reasons are the considerations in light of which an agent acts—what the agent treats as counting in favor at the time, whether or not it in fact does. Explanatory reasons cite what explains an event or action; when agents are involved, these often refer to psychological states (for example, that someone believed they were late explains why they ran).

Traditionalist conservatism, often known as classical conservatism, is a political and social philosophy that emphasizes the importance of transcendent moral principles, manifested through certain posited natural laws to which it is claimed society should adhere. It is one of many different forms of conservatism. Traditionalist conservatism, as known today, is rooted in Edmund Burke's political philosophy, as well as the similar views of Joseph de Maistre, who designated the rationalist rejection of Christianity during previous decades as being directly responsible for the Reign of Terror which followed the French Revolution. Traditionalists value social ties and the preservation of ancestral institutions above what they perceive as excessive rationalism and individualism. One of the first uses of the phrase "conservatism" began around 1818 with a monarchist newspaper named "Le Conservateur", written by Francois Rene de Chateaubriand with the help of Louis de Bonald.

The concepts of nation, culture, custom, convention, religious roots, and tradition are heavily emphasized in traditionalist conservatism. Theoretical reason is regarded as of secondary importance to practical reason. The state is also viewed as a social endeavor with spiritual and organic characteristics. Traditionalists think that any positive change arises based within the community's traditions rather than as a consequence of seeking a complete and deliberate break with the past. Leadership, authority, and hierarchy are seen as natural to humans. Traditionalism, in the forms of Jacobitism, the Counter-Enlightenment and early Romanticism, arose in Europe during the 18th century as a backlash against the Enlightenment, as well as the English and French Revolutions. More recent forms have included early German Romanticism, Carlism, and the Gaelic revival. Traditionalist conservatism began to establish itself as an intellectual and political force in the mid-20th century.

A rational agent or rational being is a person or entity that always aims to perform optimal actions based on given premises and information. A rational agent can be anything that makes decisions, typically a person, firm, machine, or software.

The concept of rational agents can be found in various disciplines such as artificial intelligence, cognitive science, decision theory, economics, ethics, game theory, and the study of practical reason.

In ethics, two values (or norms, reasons, or goods) are incommensurable (or incommensurate, or incomparable) when they do not share a common standard of measurement or cannot be compared to each other in a certain way.

There is a cluster of related ideas, and many philosophers use the terms differently. On one common usage: