Reason and science are not separate things. Aristotle's argument was possibly valid, however it was not sound, as (at least) one of his premises were incorrect

Reason and science are not separate things. Aristotle's argument was possibly valid, however it was not sound, as (at least) one of his premises were incorrect. http://en.wikipedia.org/wiki/Soundness http://en.wikipedia.org/wiki/Soundness I think the point the author is trying to make is that sometimes one must assume that their premises are correct, using one's intuition. However, one should test argument premises as soon as possible because, hey, our intuition could be wrong (just like Aristotle's was).