Philo: "[W]herever you depart, in the least, from the similarity of the cases, you diminish proportionally the evidence, and may at last bring it to a very weak analogy, which is confessedly liable to error and uncertainty." (P 74a)

"[S]urely you will not affirm that the universe bears such a resemblance to a house that we can with the same certainly infer a similar cause, or that the analogy is here entire and perfect. The dissimilitude is so striking that the utmost you can here pretend to is a guess, a conjecture, a presumption concerning a similar cause . . ." (P 74b)

"Every alteration of circumstances occasions a doubt concerning the event; and it requires new experiments to prove certainly that the new circumstances are of no . . . importance . . . The slow and deliberate steps of philosophers here, if anywhere, are distinguished from the precipitate march of the vulgar, who, hurried on by the smallest similitude, are incapable of all discernment or consideration." (P 76a)