 As might be expected, given this background, the Mohists’ logical investigations focus on analogical reasoning, and indeed they tend to treat all argumentation as fundamentally analogical in nature. They do not investigate formal logic or deductive inference, nor formulate an explicit notion of logical consequence. They do apply versions of the laws of excluded middle and non-contradiction, along with concepts of logical “permissibility” (kě 可) and “perversity” (bèi 悖, 誖) that are intertwined with a rough notion of logical  consistency.[22]  They also employ a rigorous system of quantifiers and conjunctions of implication. Still, none of these logical notions is addressed as an explicit topic of investigation, nor are they organized and presented in a systematic way. The Mohists’ discussion focuses on semantics and analogical argumentation.