ETYM Cf. French logique, Latin logicus, Greek logikos.
1. Based on known statements or events or conditions.
2. Capable of or reflecting the capability for correct and valid reasoning.

ETYM Old Eng. resonable, French raisonnable, from Latin rationabilis. Related to Reason.
1. Marked by sound judgment; SYN. sane.
2. Showing reason or sound judgment; SYN. sensible.

ETYM Old Eng. logike, French logique, Latin logica, logice, Greek logike (sc. technh), from logikos belonging to speaking or reason, from logos speech, reason, legein to say, speak. Related to Legend.
1. A system of reasoning; SYN. logical system, system of logic.
2. Reasoned and reasonable judgment.
3. The branch of philosophy that analyzes inference.
4. The principles that guide reasoning within a given field or situation.
Branch of philosophy that studies valid reasoning and argument. It is also the way in which one thing may be said to follow from, or be a consequence of, another (deductive logic). Logic is generally divided into the traditional formal logic of Aristotle and the symbolic logic derived from Friedrich Frege and Bertrand Russell.
Aristotle’s Organon is the founding work on logic, and Aristotelian methods, as revived in the medieval Christian church by the French scholar Peter Abelard in the 12th century, were used in the synthesis of ideas aimed at in scholasticism. As befitted the spirit of the Renaissance, the English philosopher Francis Bacon considered many of the general principles used as premises by the scholastics to be groundless; he envisaged that in natural philosophy principles worthy of investigation would emerge by “inductive” logic, which works backward from the accumulated facts to the principle that accounts for them.
The concept of fuzzy logic was proposed 1965 to enable computer controlled devices to deal with vague concepts. + prikaži više

ETYM Old Eng. resoun, French raison, from Latin ratio (akin to Goth. rathjô number, account, garathjan to count, German rede speech, reden to speak), from reri, ratus, to reckon, believe, think. Related to Arraign, Rate, Ratio, Ration.
1. A fact that logically justifies some premise or conclusion.
2. A rational motive for a belief or action; SYN. ground.
3. An explanation of the cause of some phenomenon.
4. The capacity for rational thought or inference or discrimination; SYN. understanding, intellect. + prikaži više