1 system of reasoning
ADJ. formal | deductive, inductive
VERB + LOGIC apply, use Philosophers use logic to prove their arguments.
2 use of reason
ADJ. compelling, exquisite, impeccable, inexorable There is a compelling logic to his main theory. | strict | internal, underlying | commercial, economic, political, scientific There is sound commercial logic in never giving credit to retailers.
VERB + LOGIC accept, follow, understand I can't follow the logic of what you are saying. | defy It's a stupid decision that completely defies logic. | apply, use You can't use the same logic in dealing with children.
PREP. ~ behind What's the logic behind this decision? | ~ in There doesn't seem to be any logic in the move.