It appears, then, that we cannot prove that our senses are ever faithful to the things they profess to report about; but we do know they often produce erroneous impressions of them. Here then is room for endless doubt; for why may they not deceive us in cases in which we cannot detect the deception? It is certain they often act irregularly; is there any consistency at all in their operations, any law to which these varieties may be referred?
It is undeniable that an object often varies in the impression which it makes upon the mind, while, on the other hand, the same impression may arise from different objects. What limit is to be assigned to this disorder? is there any sensation strong enough to assure us of the presence of the object which it seems to intimate, any such as to preclude the possibility of deception? If, when we look into a mirror, our minds are impressed with the appearance of trees, fields, and houses, which are unreal, how can we ascertain beyond all doubt whether the scene we directly look upon has any more substantial existence than the former?[160]
From these reasonings the Academics taught that nothing was certain, nothing was to be known (καταληπτὁν). For the Stoics themselves, their most determined opponents, defined the καταληπτικἡ φαντασἱα (the phantasy or impression which involved knowledge[160a]) to be one that was capable of being produced by no object except that to which it really belonged.[161]
Since then we cannot arrive at knowledge, we must suspend our decision, pronounce absolutely on nothing, nay, according to Arcesilas, never even form an opinion.[162] In the conduct of life, however, probability[163] must determine our choice of action; and this admits of different degrees. The lowest kind is that which suggests itself on the first view of the case (φαντασἱα πηθανἱ, or persuasive phantasy); but in all important matters we must correct the evidence of our senses by considerations derived from the nature of the medium, the distance of the object, the disposition of the organ, the time, the manner, and other attendant circumstances. When the impression has been thus minutely considered, the phantasy becomes απερἱσπαστος, or approved on circumspection; and if during this examination no objection has arisen to weaken our belief, the highest degree of probability is attained, and the phantasy is pronounced unembarrassed with doubt, or απερἱσπαστος.[164]
Sextus Empiricus illustrates this as follows:[165] If on entering a dark room we discern a coiled rope, our first impression may be that it is a serpent—this is the persuasive phantasy. On a closer inspection, however, after walking round it (περιοδεὑσαντες), or on circumspection, we observe it does not move, nor has it the proper colour, shape, or proportions; and now we conclude it is not a serpent; here we are determined in our belief by the περιωδεμἑνι φαντασἱα, and we assent to the circumspective phantasy. For an instance of the third and most accurate kind, viz., that with which no contrary impression interferes, we may refer to the conduct of Admetus on the return of Alcestis from the infernal regions. He believes he sees his wife; everything confirms it; but he cannot simply acquiesce in that opinion, because his mind is embarrassed or distracted περισπἁται from the knowledge he has of her having died; he asks, "What! do I see my wife I just now buried?" (Alc. 1148.) Hercules resolves his difficulty, and his phantasy is in repose, or απερἱσπατος.
The suspension then of assent (εποχἡ) which the Academics enjoined, was, at least from the time of Carneades,[166] almost a speculative doctrine;[167] and herein lay the chief difference between them and the Pyrrhonists; that the latter altogether denied the existence of the probable, while the former admitted there was sufficient to allow of action, provided we pronounced absolutely on nothing.
Little more can be said concerning the opinions of a sect whose fundamental maxim was that nothing could be known, and nothing should be taught. It lay midway between the other philosophies; and in the altercations of the various schools it was at once attacked by all,[168] yet appealed to by each of the contending parties, if not to countenance its own sentiments, at least to condemn those advocated by its opponents,[169] and thus to perform the office of an umpire.[170] From this necessity, then, of being prepared on all sides for attack,[171] it became as much a school of rhetoric as of philosophy,[172] and was celebrated among the ancients for the eloquence of its masters.[173] Hence also its reputation was continually varying: for, requiring the aid of great abilities to maintain its exalted and arduous post, it alternately rose and fell in estimation, according to the talents of the individual who happened to fill the chair.[174] And hence the frequent alterations which took place in its philosophical tenets; which, depending rather on the arbitrary determinations of its present head, than on the tradition of settled maxims, were accommodated to the views of each successive master, according as he hoped by sophistry or concession to overcome the repugnance which the mind ever will feel to the doctrines of universal scepticism.
And in these continual changes it is pleasing to observe that the interests of virtue and good order were uniformly promoted; interests to which the Academic doctrines were certainly hostile, if not necessarily fatal. Thus, although we find Carneades, in conformity to the plan adopted by Arcesilas,[175] opposing the dogmatic principles of the Stoics concerning moral duty,[176] and studiously concealing his private views even from his friends;[177] yet, by allowing that the suspense of judgment was not always a duty, that the wise man might sometimes believe though he could not know;[178] he in some measure restored the authority of those great instincts of our nature which his predecessor appears to have discarded. Clitomachus pursued his steps by innovations in the same direction;[179] Philo, who followed next, attempting to reconcile his tenets with those of the Platonic school,[180] has been accounted the founder of a fourth academy—while, to his successor Antiochus, who embraced the doctrines of the Porch,[181] and maintained the fidelity of the senses, it has been usual to assign the establishment of a fifth.
7.
We have already observed that Cicero in early life inclined to the doctrines of Plato and Antiochus, which, at the time he composed the bulk of his writings, he had abandoned for those of Carneades and Philo.[182] Yet he was never so entirely a disciple of the New Academy as to neglect the claims of morality and the laws. He is loud in his protestations that truth is the great object of his search: "For my own part, if I have applied myself especially to this philosophy, through any love of display or pleasure in disputation, I should condemn not only my folly, but my moral condition. And, therefore, unless it were absurd, in an argument like this, to do what is sometimes done in political discussions, I would swear by Jupiter and the divine Penates that I burn with a desire of discovering the truth, and really believe what I am saying."[183] And, however inappropriate this boast may appear, he at least pursues the useful and the magnificent in philosophy; and uses his academic character as a pretext rather for a judicious selection from each system than for an indiscriminate rejection of all.[184] Thus, in the capacity of a statesman, he calls in the assistance of doctrines which, as an orator, he does not scruple to deride; those of Zeno in particular, who maintained the truth of the popular theology, and the divine origin of augury, and (as we noticed above) was more explicit than the other masters in his views of social duty. This difference of sentiment between the magistrate and the pleader is strikingly illustrated in the opening of his treatise de Legibus; where, after deriving the principles of law from the nature of things, he is obliged to beg quarter of the Academics, whose reasonings he feels could at once destroy the foundation on which his argument rested. "My treatise throughout," he says, "aims at the strengthening of states and the welfare of peoples. I dread therefore to lay down any but well considered and carefully examined principles; I do not say principles which are universally received, for none are such, but principles received by those philosophers who consider virtue to be desirable for its own sake, and nothing whatever to be good, or at least a great good, which is not in its own nature praiseworthy." These philosophers are the Stoics; and then, apparently alluding to the arguments of Carneades against justice, which he had put into the mouth of Philus in the third book of his de Republicâ, he proceeds: "As to the Academy, which puts the whole subject into utter confusion, I mean the New Academy of Arcesilas and Carneades, let us persuade it to hold its peace. For, should it make an inroad upon the views which we consider we have so skilfully put into shape, it will make an extreme havoc of them. The Academy I cannot conciliate, and I dare not ignore."[185]