Thus Socrates pulled away all the foundations on which a false science had been erected, and indicated the mode by which alone the true could be established. Here he was not unlike Bacon, who pointed out the way whereby science could be advanced, without founding any school or advocating any system; but the Athenian was unlike Bacon in the object of his inquiries. Bacon was disgusted with ineffective _logical_ speculations, and Socrates with ineffective _physical_ researches. He never suffered a general term to remain undetermined, but applied it at once to particulars, and by questions the purport of which was not comprehended. It was not by positive teaching, but by exciting scientific impulse in the minds of others, or stirring up the analytical faculties, that Socrates manifested originality. It was his aim to force the seekers after truth into the path of inductive generalization, whereby alone trustworthy conclusions could be formed. He thus struck out from his own and other minds that fire which sets light to original thought and stimulates analytical inquiry. He was a religious and intellectual missionary, preparing the way for the Platos and Aristotles of the succeeding age by his severe dialectics. This was his mission, and he declared it by talking. He did not lecture; he conversed. For more than thirty years he discoursed on the principles of morality, until he arrayed against himself enemies who caused him to be put to death, for his teachings had undermined the popular system which the Sophists accepted and practised. He probably might have been acquitted if he had chosen to be, but he did not wish to live after his powers of usefulness had passed away. The services which Socrates rendered to philosophy, as enumerated by Tennemann, "are twofold,--negative and positive. _Negative_, inasmuch as he avoided all vain discussions; combated mere speculative reasoning on substantial grounds; and had the wisdom to acknowledge ignorance when necessary, but without attempting to determine accurately what is capable and what is not of being accurately known. _Positive_, inasmuch as he examined with great ability the ground directly submitted to our understanding, and of which man is the centre."