Say that you are reading book six of Aristotle’s physics, where he gives a proof that all things in motion must have extension. You then consider some finding in experimental physics that shows that particle X is in motion, but it has no extension. The following exhaust your options:
1.) Aristotle is wrong.
2.) Experimental physics is wrong.
For whatever reason, option #1 seems to be the knee-jerk response. I’ve met a number of people who would take route #2, but it isn’t a very fertile path. #3, of course, provides for more than one answer, like:
a.) “Extension” means more than one thing.
b.) “Motion” means more than one thing.
c.) What Aristotle calls “motion” can be called this, but what experimental physics calls motion cannot be called motion, except metaphorically (or vice versa).
d.) What Aristotle calls “extension” can be called this, but what experimental physics calls extension cannot be called extension, except metaphorically (or vice versa).
Options a and b assume that both Aristotle and the experimental sciences are using their terms properly; c and d hold out the possibility that one of them uses the term improperly. Figuring out the proper senses of a term is not the easiest thing to do (for example, Aristotle and St. Thomas say that “possible”, when said in logic or mathematics, is a sheer metaphor, while others seem to think that all possibility is contained and revealed in logic by way of “possible worlds”) nevertheless, there doesn’t seem to be any way of avoiding the problem. Our use of terms can’t be separated from the dispute.