see one quality in an object, feel another, hear a third; thou must, therefore, be able to distinguish sight from touch, and both from hearing?
I. Without doubt.
Spirit. Thou maintainest further, that thou seest this object red, that blue; and feelest this smooth, that rough. Thou must therefore be able to distinguish red from blue, smooth from rough?
I. Without doubt.
Spirit. And thou maintainest that thou hast not discovered this difference by means of reflection and comparison of these sensations in thyself. But perhaps thou hast learnt, by comparing the red or blue colours, the smooth or rough surfaces of objects out of thyself, what thou shouldst feel in thyself as red or blue, smooth or rough?
I. This is impossible; for my perception of objects proceeds from my perception of my own internal condition, and is determined by it, but not the contrary. I first distinguish objects by distinguishing my own states of being. I can learn that this particular sensation is indicated by the wholly arbitrary sign, red;—and those by the signs, blue, smooth, rough; but I cannot learn that the sensations themselves are distinguished, nor how they are distinguished. That they are different, I know only by being conscious of myself, and being conscious of internal change. How they differ, I cannot describe; but I know that they must differ as much as my self-consciousness differs; and this difference of sensations is an immediate, and by no means an acquired, distinction.
Spirit. Which thou canst make independently of all knowledge of the objects themselves?
