I mentioned a few posts back that I have been reading Richard J. Connell's Matter and Becoming. I ran across an excellent passage that I thought I'd share.
Let me put the matter another way. The ordinary experience of men leads them to declare that they know real things and not [merely] images, concepts, or the impressions within their knowing powers. The burden of proof, therefore, is on him who opposes this view, and we may legitimately inquire as to how he is going to verify his statement that "we do not know realities (but only images, etc.)." How is he going to show this to be true? It seems to me that the proponents of this doctrine have too often escaped being made responsible for their declaration. It is, after all, true that positions which go counter to the experience of men must be established and not gratuitously stated. How then, unless truth is to be redefined so that it does not imply an extrinsic standard, is such a position to be verified?
That last sentence is very elegantly put! To unpack: truth is the correspondence between our minds and (exterior) reality, so we need exterior reality to confirm any claim; unless we redefine "truth" to omit the reference to exterior reality, there can be no (coherent) way to confirm the claim that we don't know exterior reality. Of course, philosophers ever since Descartes have been trapped in their heads and unable to speak of truth except by redefining truth as mere consistency.
It seems philosophers are sometimes led to deny or doubt the fact that we know the exterior world because they cannot explain how. In so doing they fail to distinguish the fundamentally different questions which the mind can ask (or at least they fail to make use of these distinctions). It is especially true that certain epistemological difficulties have arisen because the question whether something is has often gone undistinguished from the questions asking what, how, or why it is. This point needs elaboration.
Everyone knows that some things are living; but most people will declare that they do not know what life is. Similarly, everyone is aware that he understands, sees, moves his arms, etc.; but the largest part of mankind is ignorant (even in part) of what these activities are and how they occur. As Professor DeKoninck of Laval University pointed out, this was Descartes' error with regard to motion: that there is motion is very evident; but what motion is, is very obscure. Thus, because it is evident that there is motion, Descartes thought it was also clear what movement is; he confused the two questions.
The last two sentences allude to Descartes' derision of Aristotle's definition of motion (Physics III.1) as superfluous: for example, in Rules for the Direction of the Mind, 24, 426, he calls them "magic words" and not understandable.
Actually the few pages in which this passage occurs are wholly excellent. I can't wait to get to the rest of the book.
Richard J. Connell, Matter and Becoming (Chicago: The Priory Press, 1966), 7.