the latter, or non-apprehending, that which does not proceed from any real object, or, if it does, fails to agree with the reality itself, not being clear or distinct. Dialectic, they said, is indispensable and is itself a virtue, embracing other particular virtues under it.° Freedom from precipitancy is a knowledge when to give or withhold the mind's assent to impressions. By wariness they mean a strong presumption against what at the moment seems probable, so as not to be taken in by it. Irrefutability is strength in argument so as not to be brought over by it to the opposite side. Earnestness (or absence of frivolity) is a habit of referring presentations to right reason. Knowledge itself they define either as unerring apprehension or as a habit or state which in reception of presentations cannot be shaken by argument. Without the study of dialectic, they say, the w r ise man cannot guard himself in argument so as never to fall ; for it enables him to distinguish between truth and falsehood, and to discriminate what is merely plausible and what is ambiguously expressed, and without it he cannot methodically put questions and give answers. Overhastiness in assertion aifects the actual course of events, so that, unless we have our perceptions well trained, we are liable to fall into unseemly conduct and heedlessness ; and in no other way will the wise man approve himself acute, nimble- witted, and generally skilful in argument ; for it belongs to the same person to converse well and to argue well, to put questions to the purpose and to respond to the questions put ; and all these qualifications are qualifications belonging to the skilled dialectician.