"Descartes had before Locke observed that the Peripatetics, intrenching themselves behind the obscurity of words, were not unlike a blind man, who, in order to be a match for his clear-sighted antagonist, should draw him into a dark cavern. 'Now,' added he, 'if this man can introduce light into the cavern, and compel the Peripatetics to fix clear ideas to their words, the victory is his own. In imitation of Descartes and Locke, I shall show that, both in metaphysics and morality, the abuse of words, and the ignorance of their true import, is a labyrinth in which the greatest geniuses have lost themselves; and, in order to set this particular in a clear light, instance, in some of those words which have given rise to the longest and sharpest disputes among philosophers: such, in metaphysics, are Matter, Space, and Infinite. It has at all times been alternately asserted that Matter felt, or did not feel, and given rise to disputes equally loud and vague. It was very late before it came into the disputants! heads to ask one another, what they were disputing about, and to annex a precise idea to the word Matter. Had they at first fixed the meaning of it, they would have perceived, if I may use the expression, that men were the creators of Matter; that Matter was not a being; that in nature there were only individuals to which the name of Body had been given; and that this word Matter could import no more than the collection of properties common to all bodies. The meaning of this word being determined, all that remained was to know, whether extent, solidity, and impenetrability, were the only properties common to all bodies; and whether the discovery of a power, such for instance as attraction, might not give rise to a conjecture that bodies had some properties hitherto unknown, such as that of sensation, which, though evident only in the organized members of animals, might yet be common to all individuals! The question being reduced to this, it would have appeared that if, strictly speaking, it is impossible to demonstrate that all bodies are absolutely insensible, no man, unless instructed by a particular revelation, can decide the question otherwise than by calculating and comparing the verisimilitude of this opinion with that of the contrary...." Instructed by the errors of great men who have gone before us, we should be sensible that our observations, however multiplied and concentrated, are scarcely sufficient to form one of those partial systems comprehended in the general system; add that it is from the depth of imagination that the several systems of the universe have hitherto been drawn; and, as our informations of remote countries are always imperfect, so the informations philosophers have of the system of the world are also defective. With a great genius and a multitude of combinations, the products of their labors will be only fictions till time and chance shall furnish then? with a general fact, to which all others may be referred.