reason (suomeksi)

syy (s: that which causes: a cause / motive for an action or determination / excuse, explanation: thought or consideration offered in support of a determination)
järki (s: (the capacity of the human mind for) rational thinking)
kohtuus (s: vanha / something reasonable)
tekosyy (s: excuse, explanation: thought or consideration offered in support of a determination)
pohtia (v: to exercise the rational faculty)
järkeillä (v: to exercise the rational faculty / to carry on a process of deduction or of induction)