The sixth cause of absurdity in reason, Hobbes says ( Leviathan Publisher: Penguin Classics , 1.5) is “the use of Metaphors, Tropes, and other Rhetoricall figures, in stead of words proper.” Metaphors are lawful in common speech, but “in reckoning [i.e., in reasoning mathematically conceived], and seeking of truth, such speeches are not to be admitted.” Stern stuff.

Flip the page and you read this: “The light of humane minds is Perspicuous Words, but by exact definitions first snuffed, and purged from ambiguity; Reason is the pace; Encrease of Science, the way; and the Benefit of man-king, the end.” Metaphors along with “senselesse and ambiguous words” are ” ignes fatui ” and to reason with such is “wandering amongst innumerable absurdities.”

To which one wants to respond: “Light”? “Snuffed and purged”? “Pace . . . way . . . end”? “Wandering”? Ignes fatui ?

Is he joking?