Logic

Logic (from the Ancient Greek: λογική, logike) originally meaning the word, or what is spoken, (but coming to mean thought or reason) is generally held to consist of the systematic study of the form of arguments. A valid argument is one where there is a specific relation of logical support between the assumptions of the argument and its conclusion. (In ordinary discourse, the conclusion of such an argument may be signified by words like 'therefore', 'hence', 'ergo' and so on.) The form of an argument type is a schematic way of representing what is common to all arguments of that type.