Not only philosophic logic — which R. B. Braithwaite says is "concerned primarily with distinguishing between necessary and contingent propositions" —¹ but logic in general serves a function in relation to psychology and behavior which, while noted even by David Hume,² is often neglected: the satisfaction of emotional and cognitive ³ needs. While it is true that logical principles do not describe psychological processes,⁴ formal logic does nevertheless play an important social-psychological role: it provides grounds for holding linguistically expressed beliefs which would otherwise be doubtful.