Plato had assimilated naming to cutting and burning. Aristotle denies the analogy: he says that cutting and burning are the same to all, or are by nature: naming is not the same to all, and is therefore not by nature.
We find here the test pointed out to distinguish what is by nature (that which Plato calls the οὐσίαν βέβαιον τῶν πραγμάτων — p. 386 E), — viz. That it is the same to all or among all. What it is to one individual, it is to another also. There are a multitude of different judging subjects, but no dissentient subjects: myself, and in my belief all other subjects, are affected alike. This is the true and real Objective: a particular fact of sense, where Subject is not eliminated altogether, but becomes a constant quantity, and therefore escapes separate notice. An Objective absolute (i.e., without Subject altogether) is an impossibility.
In the Aristotelian sense of φύσει, it would be correct to say that Language, or Naming in genere, is natural to man. No human society has yet been found without some language — some names — some speech employed and understood by each individual member. But many different varieties of speech will serve the purpose, not indeed with equal perfection, yet tolerably: enough to enable a society to get on. The uniformity (τὸ φύσει) here ceases. To a certain extent, the objects and agencies which are named, are the same in all societies: to a certain extent different. If we were acquainted with all the past facts respecting the different languages which have existed or do exist on the globe, we should be able to assign the reason which brought each particular Nomen into association with its Nominatum. But this past history is lost.
Reply of Protagoras to the Platonic objections.
Protagoras would have agreed with Plato as to combustion — that there were certain antecedent conditions under which he fully expected it, and certain other conditions under which he expected with confidence that it would not occur. Only he would have declared this (assuming him to speak conformably to his own theory) to be his own full belief and conviction, derived from certain facts and comparisons of sense, which he also knew to be shared by most other persons. He would have pronounced farther, that those who held opposite opinions were in his judgment wrong: but he would have recognised that their opinion was true to themselves, and that their belief must be relative to causes operating upon their minds. Farthermore, he would have pointed out, that combustion itself, with its antecedents, were facts of sense, relative to individual sentients and observers, remembering and comparing what they had observed. This would have been the testimony of Protagoras (always assuming him to speak in conformity with his own theory), but it would not have satisfied Plato: who would have required a peremptory, absolute affirmation, discarding all relation to observers or observed facts, and leaving no scope for error or fallibility.
Sentiments of Belief and Disbelief, common to all men — Grounds of belief and disbelief, different with different men and different ages.
Those who agree with Plato on this question, impugn the doctrine of Protagoras as effacing all real, intrinsic, distinction between truth and falsehood. Such objectors make it a charge against Protagoras, that he does not erect his own mind into a peremptory and infallible measure for all other minds.[24] He expressly recognises the distinction, so far as his own mind is concerned: he admits that other men recognise it also, each for himself. Nevertheless, to say that all men recognise one and the same objective distinction between truth and falsehood, would be to contradict palpable facts. Each man has a standard, an ideal of truth in his own mind: but different men have different standards. The grounds of belief, though in part similar with all men, are to a great extent dissimilar also: they are dissimilar even with the same man, at different periods of his life and circumstances. What all men have in common is the feeling of belief and the feeling of disbelief: the matters believed or disbelieved, as well as the ideal standard to which any new matter presented for belief or disbelief is referred, differ considerably. By rational discussion — by facts and reasonings set forth on both sides, as in the Platonic dialogues — opinions may be overthrown or modified: dissentients may be brought into agreement, or at least each may be rendered more fully master of the case on both sides. But this dialectic, the Platonic question and answer, is itself an appeal to the free action of the individual mind. The questioner starts from premisses conceded by the respondent. He depends upon the acquiescence of the respondent for every step taken in advance. Such a proceeding is relative, not absolute: coinciding with the Protagorean formula rather than with the Platonic negation of it.[25] No man ever claimed the right of individual judgment more emphatically than Sokrates: no man was ever more special in adapting his persuasions to the individual persons with whom he conversed.
[24] To illustrate the impossibility of obtaining any standard absolute and purely objective, without reference to any judging Subject, I had transcribed a passage from Steinthal’s work on the Classification of Human languages; but I find it too long for a note.
Steinthal, Charakteristik der Hauptsächlichen Typen des Sprachbaues, 2nd ed. Berlin, 1860, pp. 313-314-315.
[25] See the striking passages in the Gorgias, pp. 472 B, 474 B, 482 B; Theætêtus, p. 171 D.