rational motive - a motive that can be defended by reasoning or logical argument

occasion - reason; "there was no occasion for complaint"

score, account - grounds; "don't do it on my account"; "the paper was rejected on account of its length"; "he tried to blame the victim but his success on that score was doubtful"

wherefore, why - the cause or intention underlying an action or situation, especially in the phrase `the whys and wherefores'

explanation, account - a statement that makes something comprehensible by describing the relevant structure or operation or circumstances etc.; "the explanation was very simple"; "I expected a brief account"

faculty, mental faculty, module - one of the inherent cognitive or perceptual powers of the mind

saneness, sanity - normal or sound powers of mind

justification - a statement in explanation of some action or belief

fact - a piece of information about circumstances that exist or events that have occurred; "first you must collect all the facts of the case"

indication - (medicine) a reason to prescribe a drug or perform a procedure; "the presence of bacterial infection was an indication for the use of antibiotics"

contraindication - (medicine) a reason that makes it inadvisable to prescribe a particular drug or employ a particular procedure or treatment

cerebrate, cogitate, think - use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments; "I've been thinking all day and getting nowhere"

induce - reason or establish by induction

deduce, derive, infer, deduct - reason by deduction; establish by deduction

syllogise, syllogize - reason by syllogisms

feel, find - come to believe on the basis of emotion, intuitions, or indefinite grounds; "I feel that he doesn't like me"; "I find him to be obnoxious"; "I found the movie rather entertaining"

deduce, infer - conclude by reasoning; in logic

gather - conclude from evidence; "I gather you have not done your homework"

extrapolate, generalize, infer, generalise - draw from specific cases for more general cases

re-argue - argue again; "This politician will be forced into re-arguing an old national campaign"

present, lay out, represent - bring forward and present to the mind; "We presented the arguments to him"; "We cannot represent this knowledge to our formal reason"

expostulate - reason with (somebody) for the purpose of dissuasion

defend, fend for, support - argue or speak in defense of; "She supported the motion to strike"

cerebrate, cogitate, think - use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments; "I've been thinking all day and getting nowhere"

rationalise away, rationalize away - substitute a natural for a supernatural explanation of; "you can rationalize away all the strange noises you hear--there is no poltergeist in the house!"

theorize - form or construct theories; "he thinks and theorizes all day"

theorize - construct a theory about; "Galileo theorized the motion of the stars"

ratiocinate - reason methodologically and logically

compute, calculate, cipher, cypher, figure, reckon, work out - make a mathematical calculation or computation

categorise, categorize - place into or assign to a category; "Children learn early on to categorize"

speculate - talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion; "We were speculating whether the President had to resign after the scandal"