Athenian hoplite as they were for an English knight. Both, when encased in their armour, were conspicuous figures incapable of any very nimble movements, and needing an attendant squire to take charge of their war panoply. With both physical conditions led to a moral code of ‘noblesse oblige,’ and for a time war became almost a gentlemanly diversion. In neither case it is true did these conditions last long: the moral degeneration caused by the Peloponnesian War destroyed the one, and the physical changes brought about by the invention of gunpowder put an end to the other. Ancient as distinguished from modern warfare really ends with the fifth century B.C., for the next age brought a revolution to Greece. War ceased to be an art and became a science. The end of the Peloponnesian War coincided with the spread of the Sophistic spirit; warfare was subjected to the same sort of investigation and criticism as the other departments of life; and specialization, with all its advantages and disadvantages, began. The later years of the Peloponnesian War had shown the importance of cavalry and its proper functions in the attack and support of infantry; but the first great change came when Iphicrates the Athenian discovered that a hoplite force was not invincible by light armed troops, if these latter were properly handled. His defeat of a detachment of Spartan heavy armed infantry was in itself an insignificant event, but it created a revolution in military tactics comparable to that brought about by the success of the English archers over the French knights at Creçy. Up till that time the hoplite in popular estimation held much the same position as a battleship does in modern sea warfare; it was considered as hopeless for peltasts to engage hoplites as it would be for a light cruiser to attack a Dreadnought. With the fall of the citizen soldier came the rise of the mercenary and the professional fighting man. A Greek force ceased to be a homogeneous unit and split up into the component elements of a modern army. ‘The light armed men are the hands, the horse the feet, the infantry the breast, and the general the head’; such was the saying of Iphicrates; and the Theban tacticians, notably Epaminondas, followed him in combining cavalry and light infantry with the heavy armed phalanx. Philip of Macedon improved upon his Theban teacher’s example and soon a standing army was established which disregarded all the old traditions of chivalry. The Greeks had their first warning in the ruthless destruction of Olynthus and the two systems met in final conflict at Chæronea. The professional soldier won, and by the end of the fourth century the ancient ideals had disappeared.