And the perception of their contrast or relation quickens and sets in motion the mind, which is puzzled by the confused intimations of sense, and has recourse to number in order to find out whether the things indicated are one or more than one.

Number replies that they are two and not one, and are to be distinguished from one another.

Again, the sight beholds great and small, but only in a confused chaos, and not until they are distinguished does the question arise of their respective natures; we are thus led on to the distinction between the visible and intelligible.
That was what I meant when I spoke of stimulants to the intellect; I was thinking of the contradictions which arise in perception.

The idea of unity, for example, like that of a finger, does not arouse thought unless involving some conception of plurality; but when the one is also the opposite of one, the contradiction gives rise to reflection; an example of this is afforded by any object of sight.

All number has also an elevating effect; it raises the mind out of the foam and flux of generation to the contemplation of being, having lesser military and retail uses also.