(Inner) and EXOTERIC (Outer). These words have been much discussed with reference to the Greek philosophy, and especially to the system of Aristotle. Esoteric. They have also been applied to various other schools, but always enveloped in some kind of obscurity and doubt, which philology has vainly attempted entirely to dissipate. There are particularly three schools of ancient philosophy with respect to which these words have been employed—those of Pythagoras, Plato, and Aristotle.

Little is known with certainty of the school of Pythagoras; but according to the historians of philosophy the adepts of the Pythagorean institution were divided into several classes according to the degree of their attainments; the Esoteric were those who had learnt more completely the doctrines of their master, and were received into the bosom of the society. The Exoteric were the more simple inquirers who waited without till by enduring trials and privations (among others, silence for five years), they were fitted for reception into the inner communion.

In the doctrine of Plato these two words have a meaning different from this. As they are not applied to the disciples but to the opinions of the master, it has been said that Plato had two sets of doctrines, the one to be communicated only to the more intelligent and faithful disciples, the other to be made known to the vulgar. If this were true, it would be a grave charge against the philosophy of the time of Pericles if it had dissembled its true convictions on the great questions which have always occupied the human mind; if the disciple of Socrates, frightened by the punishment of his master, had veiled the truth to give us in his dialogues only a faint and insincere reflection of his philosophic faith. But the admirable dialogues which have come down to us afford irrefragable evidence that Plato as well as his master has concealed nothing, but has given us his entire views in all their fulness and all their depth, and that all the regrets about losses and concealments are perfect chimeras.

Some have thought that the allusion made by Aristotle (Physica, lib. iv. c. 2) to the unwritten opinions of Plato, ἐν τοῖς ἀγροῦσιν ἀπόρρητοις δόγμασι, referred to concealed doctrines; but it is much more likely that those unwritten dogmas were those which were but orally communicated, and not found in the dialogues only because they were less important than those which were written. Pythagoras, in the midst of a hostile and barbarous people, held a mysterious and double doctrine; Plato, in the groves of the Academy, taught such as were perfectly accessible to all, and which we now possess in his works. In these it is impossible to distinguish between the esoteric and exoteric.

This distinction is still less applicable to Aristotle than to Plato, although relatively it may appear more so, for Aristotle himself separates his works into exoteric and acroamatic or esoteric. There are many passages in which Aristotle speaks of his exoteric works; and it is in studying these carefully that we may ascertain the true meaning of the word, at least as far as relates to the Peripatetic philosophy. The result of a strict analysis will show that Aristotle never held a concealed doctrine that had any resemblance to that of Pythagoras.

In what sense then is the word esoteric in Aristotle to be taken if the exoteric works are not those which were delivered to the profane or vulgar, and the philosophic or acroamatic works those which were confided to the approved disciples? The difference does not refer to the nature of the teaching, much less to the readers, but only to the forms and processes of the expositions.

The exoteric and the philosophic works treat of the same subjects; in the first he only gives the elements that are more superficial and more easily understood by the less intelligent, but for the second he reserves the arguments that are difficult and weighty and most deserving the meditation of the philosopher. This we hold to be the most plausible explanation of the words esoteric and acroamatic or esoteric when used in relation to the Peripatetic philosophy. words esoteric and exoteric are sometimes applied to the religious sentiment as prevailing at certain times and in various states. It was a necessary result of the position occupied by the ancient world, that in proportion as scientific culture came to be more generally diffused, the opposition noticed by Polybius between the subjective conviction of the individual and the public religion of the state became more strongly marked. The wiser part endeavoured to maintain the popular religion, merely because they recognised in it a necessary means to political ends. Strabo, who lived in the age of Augustus Caesar, says "The multitude of women and the entire mass of the common people cannot be led to piety by the doctrines of philosophy; to effect this, therefore, superstition is necessary, which may call in the aid of myths and tales of wonder." And Seneca, in his treatise against superstition, writes, "The whole of that vulgar crowd of gods which, for ages past, a Protean superstition has been accumulating, we shall worship so as never to forget that the worship we pay them is due rather to good manners than to their own worth. All such rites the sage will observe because they are commanded by the laws, not because they are pleasing to the gods." It was impossible on any grounds of truth to establish a fellowship of religious interest between the cultivated class and the uneducated; and thus the philosophic class, while outwardly professing devotion to the popular religion, inwardly despised it as a system of superstition.

The Essenes among the Jews mingled the Chaldaic, Parsee, and Platonic doctrines, with an allegorical interpretation of the Old Testament, and it was only those who had undergone a noviciate of three years that were admitted into full communion in the mystical and ascetic rites of the society. The various sections of the Gnostics in the second and third century of the Christian church adopted the same secret mysteries to which the initiated only were admitted. (Brandis Manuel de l'Histoire de la Philosophie Grceque et Romaine; Ritter's History of Philosophy; Dictionnaire des Sciences Philosophiques; Neander's History of the Christian Church.)