REASON

I. noun Etymology: Middle English resoun, from Anglo-French raisun, from Latin ration-, ratio ~, computation, from reri to calculate, think; probably akin to Gothic rathjo account, explanation Date: 13th century 1. a statement offered in explanation or justification , a rational ground or motive , a sufficient ground of explanation or of logical defense, the thing that makes some fact intelligible ; cause , 2. a. the power of comprehending, inferring, or thinking especially in orderly rational ways ; intelligence , proper exercise of the mind, sanity , the sum of the intellectual powers, treatment that affords satisfaction, II. verb (~ed; ~ing) Date: 15th century intransitive verb 1. to take part in conversation, discussion, or argument, to talk with another so as to influence actions or opinions , to use the faculty of ~ so as to arrive at conclusions, transitive verb to justify or support with ~s, to persuade or influence by the use of ~, to discover, formulate, or conclude by the use of ~ , see: think ~er noun