Rasional

Rasional is an adjective used in Indonesian and Malay to describe reasoning-based or logically grounded attributes, explanations, or actions. It denotes adherence to reason, evidence, or good judgment, rather than impulse or superstition. In everyday speech, something described as rasional is considered sensible or well thought out, and a person who acts in a rasional way is acting rationally.

Etymology and usage: The word derives from Latin rationalis, related to ratio meaning reasoning or calculation. In Indonesian and Malay, rasional is widely used in academic, scientific, and formal contexts to contrast with emotional or irrational approaches. The term can modify statements, methods, or decisions, as in rasional hujah (logical argument) or tindakan rasional (rational action).

In mathematics: In Indonesian, bilangan rasional refers to rational numbers—numbers that can be expressed as a ratio p/q, where p and q are integers and q is not zero. This class includes integers, fractions, and repeating decimals that terminate or repeat. Rational numbers are contrasted with irrational numbers, which cannot be expressed as such a ratio.

In philosophy and social sciences: Rasional often appears in discussions of rationalism, rational choice theory, or rational decision-making, where reasoning and evidence are emphasized in acquiring knowledge or making choices. The concept underpins methods that seek to optimize outcomes under given constraints.

See also: rationality, rationalism, rational decision-making, rasionalisasi (rationalization).