Reason

Reason (also called rationality, intellect, or reasoning) is the cognitive capacity by which people hold ideas and arrive at conclusions derived from them. In general usage, something reasonable refers to what is agreeable to intellect and not contradictory.

The word originally comes from Arabic "caql", meaning mind or understanding. In philosophy, reason is typically defined as the means by which one distinguishes truth from falsehood, or evaluates choices, following verifiable steps that do not rely solely on feeling or custom.

Reasoning and its forms

Reasoning is the process of moving from premises (accepted statements) to a conclusion. Two main types are commonly distinguished. The first is deductive reasoning, in which, if the premises are true, the conclusion must necessarily be true. The second is inductive reasoning, in which many examples give rise to a general rule, but the conclusion is never fully guaranteed.

Reason and logic

Logic is the science that studies the principles of correct reasoning. Reason is a capacity; logic is a codified method for testing whether an argument is formally valid. An argument may be formally valid yet have a false conclusion if its premises are false.

Disputes over its limits

Philosophers have disagreed on how much reason alone can achieve. Some hold that fundamental knowledge comes from intellect only, emphasizing mathematics and logical laws. Others hold that knowledge depends on sense experience, with reason merely as a tool for processing information. The comparison between reason and sensation or belief remains an enduring topic in the history of thought.