Aristotle was the father of logic, and Hegel and Kant think there has been no improvement upon it since his day. And this became to him the real organon of science. "He supposed it was not merely the instrument of thought, but the instrument of investigation." Hence it was futile for purposes of discovery, although important to aid the processes of thought. Induction and syllogism are the two great instruments of his logic. The one sets out from particulars already known to arrive at a conclusion; the other sets out from some general principle to arrive at particulars. The latter more particularly characterized his logic, which he presented in sixteen forms, showing great ingenuity, and useful as a dialectical exercise. This syllogistic process of reasoning would be incontrovertible, if the _general_ were better known than the _particular_. But it is only by induction, which proceeds from the world of experience, that we reach the higher world of cognition. We arrive at no new knowledge by the syllogism, since the major premise is more evident than the conclusion, and anterior to it. Thus he made speculation subordinate to logical distinctions, and his system, when carried out by the schoolmen, led to a spirit of useless quibbling. Instead of interrogating Nature, as Bacon led the way, they interrogated their own minds, and no great discoveries were made. From a want of a proper knowledge of the conditions of scientific inquiry, the method of Aristotle became fruitless. [Footnote: Maurice, _Anc. Phil_. See Whewell, _Hist. Ind. Science_.] Though Aristotle wrote in a methodical manner, yet there is great parsimony of language. There is no fascination in his style. It is without ornament, and very condensed. His merit consisted in great logical precision, and scrupulous exactness in the employment of terms. [Sidenote: The Skeptics.] Philosophy, as a great system of dialectics, as an analysis of the power and faculties of the mind, as a method to pursue inquiries, as an intellectual system merely, culminated in Aristotle. He completed the great fabric of which Thales laid the foundation. The subsequent schools of philosophy directed attention to ethical and practical questions, rather than to intellectual phenomena. The skeptics, like Pyrrho, had only negative doctrines, and had a disdain of those inquiries which sought to penetrate the mysteries of existence. They did not believe that absolute truth was attainable by man. And they attacked the prevailing systems with great plausibility. Thus Sextus attacked both induction and definitions. "If we do not know the thing we define," said he, "we do not comprehend it because of the definition, but we impose on it the definition because we know it; and if we are ignorant of the thing we would define, it is impossible to define it." Thus the skeptics pointed out the uncertainty of things and the folly of striving to comprehend them.