Let a man heat one band and cool the other; the same water will, at the same time, seem both hot and cold, according to the disposition of the different organs.

A small degree of any quality, succeeding a greater, produces the same sensation, as if less than it really is, and even sometimes as the opposite quality.

Any gentle pain, that follows a violent one, seems as nothing, or rather becomes a pleasure; as on the other hand a violent pain, succeeding a gentle one, is doubly grievous and uneasy.
This no one can doubt of with regard to our passions and sensations.

But there may arise some difficulty with regard to our ideas and objects.
When an object augments or diminishes to the eye or imagination from a comparison with others, the image and idea of the object are still the same, and are equally extended in the retina, and in the brain or organ of perception.

The eyes refract the rays of light, and the optic nerves convey the images to the brain in the very same manner, whether a great or small object has preceded; nor does even the imagination alter the dimensions of its object on account of a comparison with others.