At Physics IV,8, 216a26-7, Aristotle cracks a joke. It is one of the relatively few deliberate jokes in the corpus, and its occurrence here is not without significance. Aristotle in these chapters is arguing against those who believe in the existence of the void, or vacuum, or empty space; he says, ‘even if we consider it on its own merits the so-called vacuum will be found to be really vacuous.'
To be sure, this is not a very funny joke; what is interesting about it, though, is that it underlines the general attitude of dismissive flippancy that seems to run through Aristotle's consideration of the void. He seems to refuse to take the hypothesis of the void at all seriously. He never argues directly that the void does not or cannot exist, but contents himself with criticizing the arguments that other thinkers had advanced in its favour.