 The crucial premise (italicized above) purports to reveal a contradiction that follows from the assumption that something exists without a sufficient reason. Since “nothing” cannot both be something and nothing at the same time (according to PC), the conclusion (or PSR) is claimed to follow. This proof was the subject of an incisive critique by Wolff’s contemporary and critic, Christian August Crusius (1715–75), who (among other things) accuses Wolff of an equivocation with the term “nothing”, and once the two different meanings of this term are identified (viz. nothing as the opposite of something, on one hand, and nothing as a non-being, on the other), the supposed contradiction, purported to follow from the assumption, cannot be established (Crusius 1741).