An Enquiry Concerning Human Understanding - pg. 96

SECTION 2
OF THE ORIGIN OF IDEAS

EVERY one will readily allow, that there is a considerable difference between the perceptions of the mind, when a man feels the pain of excessive heat, or the pleasure of moderate warmth, and when he afterwards recalls to his memory this sensation, or anticipates it by his imagination. There faculties may mimic or copy the perceptions of the senses; but they never can entirely reach the force and vivacity of the original sentiment. The utmost we say of them, even when they operate with greatest vigour, is, that they represent their object in so lively a manner, that we could almost say we feel or see it: But, except the mond be disordered by disease or madness, they never can arrive at such apitch of vivacity, as to render these perceptions altogether undistinguishable. All the colours of poety, however splendid, can never paint natural obkects in such a manner as to make the description be taken for a real landscape. The most lively thought is still inferior to the dullest sensation.