to show how a siege should be resisted, the various kinds of instruments to be used, manœuvres to be practised, ways of sending letters without being detected, and without even the bearers knowing about it (c. 31, a very curious one), &c. It contains a good deal of information on many points in archæology, and is especially valuable as containing a large stock of words and technical terms connected with warfare, denoting instruments, &c., which are not to be found in any other work. From the same circumstance, many passages are difficult. The book was first discovered by Simler in the Vatican library. It was edited first by Isaac Casaubon with a Latin version and notes, and appended to his edition of Polybius. (Paris, 1609.) It was republished by Gronovius in his Polybius, vol. iii. Amsterdam, 1670, and by Ernesti, Leipzig, 1763. The last edition is that of J. C. Orelli, Leipzig, 1818, with Casaubon's version and notes and an original commentary, published as a supplement to Schweighaeuser's Polybius. Besides the Vatican MS. there are three at Paris, on which Casaubon founded his edition, and one in the Laurentian library at Florence. This last is, according to Orelli (Praef. p. 6), the oldest of all. The work contains many very corrupt and mutilated passages. An epitome of the whole book, not of the fragment now remaining, was made by Cineas, a Thessalian, who was sent to Rome by Pyrrhus, 279, B. C. (Aelian, Tact. 1.) This abridgement is referred to by Cicero (Cic. Fam. 9.25). [A. A.]
AENE'lUS or AENE'SIUS (Αἰνήιος or Αἰνήσιος), a surname of Zeus, under which he was worshipped in the island of Cephalenia, where he had a temple on mount Aenos. (Hes. apud . Schol. ad Apollon. Rhod. 2.297.)
[L. S.]
AENESIDE'MUS (Αἰνησίδημος), the son of Pataieus, and one of the body-guards of Hippocrates, tyrant of Gela, was the son of Theron, the ruler of Agrigentum in the time of the Persian war. (Hdt. 7.154, 165.) [THERON.]
AENESIDE'MUS (Αἰνησίδημος), a celebrated sceptic, born at Cnossus, in Crete, according to Diogenes Laertius (9.116), but at Aegae, according to Photius (Phot. Bibl. 212), probably lived a little later than Cicero. He was a pupil of Heracleides and received from him the chair of philosophy, which had been handed down for above three hundred years from Pyrrhon, the founder of the sect. For a full account of the sceptical system see PYRRHON. As Aenesidemus differed on many points from the ordinary sceptic, it will be convenient before proceeding to his particular opinions, to give a short account of the system itself. The sceptic began and ended in universal doubt. He was equally removed from the academic who denied, as from the dogmatic philosopher who affirmed; indeed, he attempted to confound both in one, and refute them by the same arguments. (Sext. Emp. 1.1.) Truth, he said, was not to be desired for its own sake, but for the sake of a certain repose of mind (ἀταραξία) which followed on it, an end which the septic best attained in another way, by suspending his judgment (ἐποχή), and allowing himself literally to rest in doubt. (1.4.) With this view he must travel over the whole range of moral, metaphysical, and physical science. His method is the comparison of opposites, and his sole aim to prove that nothing call be proved, or what he termed, the ἰσοσθένεια, of things. In common life he may act upon Φαινόμενα with the rest of men : nature, law, and custom are allowed to have their influence; only when impelled to any vehemlent effort we are to remember that, here too, there is much to be said on both sides, and are not to lose our peace of mind by grasping at a shadow.
The famous δέκα τρόποι of the sceptics were a number of heads of argument intended to overthrow truth in whatever form it might appear. [PYRRHON.] The opposite appearances of the moral and natural world (Sext. Emp. 1.14), the fallibility of intellect and sense, and the illusions produced upon them by intervals of time and space and by very change of position, were the first arguments by which they assailed the reality of things. We cannot explain what man is, we cannot explain what the senses are: still less do we know the way in which they are acted upon by the mind (2.4-7): beginning with οὐδέν ὁρίζω, we must end with οὐδὲν μᾶλλον We are not certain whether material objects are anything but ideas in the mind: at any rate the different qualities which we perceive in them may be wholly dependent on the percipient being; or, supposing them to contain quality as well as substance, it may be one quality varying with the perceptive power of the different senses. (2.14.) Having thus confounded the world without and the world within, it was a natural transition for the sceptic to confound physical and metaphysical argluments. The reasonings of natural philosophy were overthrown by metaphysical subtleties, and metaphysics made to look absurd by illustrations only applicable to material things. The acknowledged imperfection of language was also pressed into the service; words, they said, were ever varying in their signification, so that the ideas of which they were the signs must be alike variable. The leading idea of the whole system was, that all truth involved either a vicious circle or a petitio principii, for, even in the simplest truths, something must be assumed to make the reasoning applicable. The truth of the senses was known to us from the intellect, but the intellect operated through the senses, so that our knowledge of the nature of either depends upon the other. There was, however, a deeper side to this philosophy. Everything we know, confessedly, runs up into something we do not know: of the true nature of cause and effect we are ignorant, and hence to the favourite method, ἀπὸ τοῦ εἰς ἄπειρον ἐκβάλλειν, or arguing backward fiom cause to cause, the very imperfection of human faculties prevents our giving an answer. We must know what we believe; and how can we be sure of secondary causes, if the first cause be wholly beyond us? To judge, however, from the sketch of Sextus Empiricus (Pyrrh. Hyp.), it was not this side of their system which the sceptics chiefly urged: for the most part, it must be confessed, that they contented themselves with dialectic subtleties, which were at once too absurd for refutation, and impossible to refute.
The causes of scepticism are more fully given under the article PYRRHON. One of the most remarkable of its features was its connexion with the later philosophy of the Ionian school. From the failure of their attempts to explain the phenomena of the visible world, the Ionian philosophers were insensibly led on to deny the order and harmony of
