Read it through once

When I attempt to reason concerning the origin or the use of any of the internal senses, I hesitate, and am embarrassed by a difficulty which I cannot overcome. There is in man, I see, a faculty which I do not possess; and, of course, can neither judge of, nor describe it. In like manner, when I attempt to reason concerning those powers, which affect the imagination, and raise all sorts of passions and emotions, I am embarrassed by a sort of consciousness, that I want principles, or language, to describe properly the varied and subtile operations, which I would explain.