He had every motive, not merely from ambition, of conquest, but even from the necessities of defence, to turn them to account: and he brought to the task military genius and aptitude of the highest order. In arms, in evolutions, in engines, in regimenting, in war-office arrangements, he introduced important novelties; bequeathing to his successors the Macedonian military system, which, with improvements by his son, lasted until the conquest of the country by Rome, near two centuries afterwards. [116] Isokrates, in several of his discourses, notes the gradual increase of these mercenaries—men without regular means of subsistence, or fixed residence, or civic obligations. Or. iv. (Panegyr.) s. 195; Or. v. (Philippus), s. 112-142; Or. viii. (De Pace), s. 31-56. [117] Xenoph. Magist. Equit. ix. 4. Οἶδα δ᾽ ἐγὼ καὶ Λακεδαιμονίοις τὸ ἱππικὸν ἀρξάμενον εὐδοκιμεῖν, ἐπεὶ ξένους ἱππέας προσέλαβον· καὶ ἐν ταῖς ἄλλαις πόλεσι πανταχοῦ τὰ ξενικὰ ὁρῶ εὐδοκιμοῦντα. Compare Demosth. Philippic. i. p. 46; Xenoph. Hellenic. iv. 4, 14; Isokrates, Orat. vii. (Areopagit.), s. 93. [118] For an explanation of the improved arming of peltasts introduced by Iphikrates, see Vol. IX. Ch. lxxv. p. 335 of this History. Respecting these improvements, the statements both of Diodorus (xv. 44) and of Nepos are obscure. MM. Rüstow and Köchly (in their valuable work, Geschichte des Griechischen Kriegswesens, Aarau, 1852, B. ii. p. 164) have interpreted the statements in a sense to which I cannot subscribe. They think that Iphikrates altered not only the arming of peltasts, but also that of hoplites; a supposition, which I see nothing to justify. [119] Besides the many scattered remarks in the Anabasis, the Cyropædia is full of discussion and criticism on military phænomena. It is remarkable to what an extent Xenophon had present to his mind all the exigencies of war, and the different ways of meeting them. See as an example, Cyropæd. vi. 2; ii. 1. The work on sieges, by Æneas (Poliorketica), is certainly anterior to the military improvements of Philip of Macedon: probably about the beginning of his reign. See the preface to it by Rüstow and Köchly, p. 8, in their edition of Die Griechischen Kriegs-schriftsteller, Leips. 1853. In this work, allusion is made to several others, now lost, by the same author—Παρασκευαστικὴ βίβλος, Ποριστικὴ Βίβλος, Στρατοπεδευτικὴ, etc.