In logic, a contradiction consists of a logical incompatibility between two or more propositions. It occurs when the propositions, taken together, yield two conclusions which form the logical inversions of each other. Illustrating a general tendency in applied logic, Aristotle’s law of noncontradiction states that “One can't say of something that it's and that it isn't in the same respect and at the same time.” By extension, outside of formal logic, one can speak of contra… (More on Contradiction)