ON HUMAN UNDERSTANDING. 345 



perceived by sensible phantasms, thing's intelligible are perceived by intelligi- 

 ble phantasms; and consequently that virtue and vice, truth and falsehood, 

 time, space, and numbers, have all their pictures and phantasms, as well as 

 plants, houses, and animals. 



Epicurus admitted a part of this hypothesis, and taught it contemporane- 

 ously at Mitylene, but the greater part he openly opposed and ridiculed. He 

 concurred in the doctrine that the mind perceives sensible objects by means 

 of sensible images ; but he contended that those images are as strictly mate- 

 rial as the objects from which they emanate ; and that if we allow them to 

 possess material qualities, we must necessarily allow them at the same time 

 to possess the substance to which such qualities appertain. Epicurus, there- 

 fore, believed the perceptions of the mind to be real and substantial effigies, 

 and to these effigies he gave the name of ettu>\a (idola), or SPECIES, in contra- 

 distinction to the unsubstantial PHANTASMS of Aristotle, and the intellectual or 

 formative IDEAS of Plato. He maintained that all external objects are per- 

 petually throwing off fine alternate waves of different flavours, odours, co- 

 lours, shapes, and other qualities ; which, by striking against their appropriate 

 senses, excite in the senses themselves a perception of the qualities and 

 presence of the parent object ; and are immediately conveyed by the sentient 

 channel to the chamber of the mind, or sensory, without any injury to their 

 texture : in the same manner as heat, light, and magnetism pervade solid sub- 

 stances, and still retain their integrity. And he affirmed, farther, that instead 

 of the existence of an imaginary intelligible world, throwing off intelligible 

 images, it is from the sensible or material world alone that the mind, by the 

 exercise of its proper faculties, in union with that of the corporeal senses, 

 derives every branch of knowledge, physical, moral, or mathematical. 



If this view of the abstruse subject before us be correct, as I flatter myself 

 it is, I may recapitulate in few words, that the external perceptions of the 

 mind are, according to Plato, the primitive or intellectual patterns from which 

 the forms and other qualities of objects have been taken ; according to Aris- 

 totle, unsubstantial pictures of them, as though reflected from a mirror; and, 

 according to Epicurus, substantial or material effigies ;*?uch perceptions be 

 ing under the first view of them denominated IDEAS ; under the second, PHAN- 

 TASMS; under the third, idola, or SPECIES. 



While such were the fixed and promulgated tenets of Plato. Aristotle, and 

 Epicurus, there were other philosophers of Greece, or who at least have been 

 so denominated, that openly professed themselves to be without tenets of any 

 kind ; who declared that nothing was known or could be known upon any 

 subject ; and who, consequently, inculcated a universal skepticism. Of this 

 delirious class of disputants, who were suffered to wander at large without a 

 strait waistcoat, there are two that are pre-eminently entitled to our atten- 

 tion, Pyrrho and Arcesilas. Pyrrho studied first in the atomic school of De- 

 mocritus, and seems to have lost his senses upon the question of the infinite 

 divisibility of matter, a question which has not unfrequently given birth to the 

 same disease in modern times. He first doubted the solidity of its elemen- 

 tary atoms, he next found out, that if these be not solid, every thing slips 

 away from the fingers in a moment the external world becomes a mere show 

 and there is no truth or solidity in any thing. He was not abio to prove the 

 solidity of the elementary atoms of matter. He hence doubted of every 

 thing ; advised aU the world to do the same ; and established a school for the 

 purpose of inculcating this" strange doctrine. In every other respect he was 

 a man of distinguished accomplishments, and so highly esteemed by his 

 countrymen, as to have been honoured with the dignity of chief priest, and 

 exempted from public taxation. But to such a formidable extreme did this 

 disease of skepticism carry him, that one or more of his friends, as we are 

 gravely told in history, were obliged to accompany him wherever he went, 

 that he might not be run over by carriages, or fall down precipices. Yet he 

 contrived, by some means or other, to live longer than most men of caution 

 and common sense ; for we find him at last dying of a natural death, at the 

 good old age of ninety. 



