*The Sceptical school of philosophy* claims in this connection a brief notice. Though so identified in common speech with the name of a single philosopher, that Pyrrhonism is a synonyme for Scepticism, it was much older than Pyrrho, and greatly outnumbered his avowed followers. It was held by the teachers of this school that objective truth is unattainable. Not only do the perceptions and conceptions of different persons vary as to every object of knowledge; but the perceptions and conceptions of the same persons as to the same object vary at different times. Nay, more, at the same time one sense conveys impressions which another sense may negative, and not infrequently the reflective faculty negatives all the impressions derived from the senses, and forms a conception entirely unlike that which would have taken shape through the organs of sense. The soul that seeks to know, is thus in constant agitation. But happiness consists in imperturbableness of spirit, that is, in suspense of judgment; and as it is our duty to promote our own happiness, it is our duty to live without desire or fear, preference or abhorrence, love or hatred, in entire apathy,—a life of which Mohammed’s fabled coffin is the fittest symbol.
The *New Academy*, whose philosophy was a hybrid of Platonism and Pyrrhonism, while it denied the possibility of ascertaining objective truth, yet taught that on all subjects of speculative philosophy probability is attainable, and that, if the subject in hand be one which admits of being acted upon, it is the duty of the moral agent to act in accordance with probability,—to pursue the course in behalf of which the more and the better reasons can be given. There are moral acts and habits which seem to be in accordance with reason and the nature of things. We may be mistaken in thinking them so; yet the probability that they are so creates a moral obligation in their favor. The New Academy professed a hypothetical acquiescence in the ethics of the Peripatetic school, maintaining, therefore, that the mean between two extremes is probably in accordance with right and duty, and that virtue is probably man’s highest good, yet probably not sufficient in itself without the addition of exterior advantages.