ABSTRACT
There is something to be said now and then for refusing to take anything for granted, a Cartesian act that suspends assumed knowledge.
For example, we have all had a father, and while we may imagine the way he appeared, or we may recall some particular moment with him, or think of him through the sound of his name, or just sense him as part of ordinary unconscious contemplation, yet all these thinkings will be rendered under the generic concept of `father'. But what exactly is that, we may ask, what is a father? Simply because we have one, can remember moments with him and can name him does not suggest that we know what he is.
