To achieve accurate knowledge of others, if such a thing were possible, we could only ever arrive at it through the slow and unsure recognition of our own initial optical inaccuracies. However, such knowledge is not possible: for, while our vision of others is being adjusted, they, who are not made of mere brute matter, are also changing; we think we have managed to see them more clearly, but they shift; and when we believe we have them fully in focus, it is merely our older images of them that we have clarified, but which are themselves already out of date.