The two main tasks of the later Greek philosophy were, as Cicero often insists, the establishment of a criterion such as would suffice to distinguish the true from the false, and the determination of an ethical standard[71].  We have in the Academica Cicero’s view of the first problem:  that the attainment of any infallible criterion was impossible.  To go more into detail here would be to anticipate the text of the Lucullus as well as my notes.  Without further refinements, I may say that Cicero in this respect was in substantial agreement with the New Academic school, and in opposition to all other schools.  As he himself says, the doctrine that absolute knowledge is impossible was the one Academic tenet against which all the other schools were combined[72].  In that which was most distinctively New Academic, Cicero followed the New Academy.

It is easy to see what there was in such a tenet to attract Cicero.  Nothing was more repulsive to his mind than dogmatism.  As an orator, he was accustomed to hear arguments put forward with equal persuasiveness on both sides of a case.  It seemed to him arrogant to make any proposition with a conviction of its absolute, indestructible and irrefragable truth.  One requisite of a philosophy with him was that it should avoid this arrogance[73].  Philosophers of the highest respectability had held the most opposite opinions on the same subjects.  To withhold absolute assent from all doctrines, while giving a qualified assent to those which seemed most probable, was the only prudent course[74].  Cicero’s temperament also, apart from his experience as an orator, inclined him to charity and toleration, and repelled him from the fury of dogmatism.  He repeatedly insists that the diversities of opinion which the most famous intellects display, ought to lead men to teach one another with all gentleness and meekness[75].  In positiveness of assertion there seemed to be something reckless and disgraceful, unworthy of a self-controlled character[76].  Here we have a touch of feeling thoroughly Roman.  Cicero further urges arguments similar to some put forward by a long series of English thinkers from Milton to Mill, to show that the free conflict of opinion is necessary to the progress of philosophy, which was by that very freedom brought rapidly to maturity in Greece[77].  Wherever authority has loudly raised its voice, says Cicero, there philosophy has pined.  Pythagoras[78] is quoted as a warning example, and the baneful effects of authority are often depicted[79].  The true philosophic spirit requires us to find out what can be said for every view.  It is a positive duty to discuss all aspects of every question, after the example of the Old Academy and Aristotle[80].  Those who demand a dogmatic statement of belief are mere busybodies[81].  The Academics glory in their freedom of judgment.  They are not compelled to defend an opinion whether they will or no, merely because one of their predecessors has laid it down[82].