Personal connections would have drawn Aristotle to Macedonia, for his father had been a doctor at the court of King Amyntas III; Philip had also been friendly with his former patron Hermeias, who maintained an impressive local tyranny on the western coast of Asia and had married his daughter to the philosopher. Later, men said that he had taken the job to persuade Philip to rebuild his ruined home town Stageira, now annexed to Macedonia's eastern borders, but the story was told of too many philosophers at court to be especially convincing, and the ruin of Stageira was probably an error of legend; the motive may have gained favour as an answer to those who had protested, probably unfairly, that Aristotle had grown to ignore his fellow citizens. Privately, Aristotle did receive a handsome fee for his services, and so as his will proves, he died a rich man: according to rumour, Philip and Alexander also patronized his researches into natural history by giving him gamekeepers to tag Macedonia's wild animals. As the observations for his astonishing works on zoology can be shown to have been made almost exclusively on the island of Lesbos, this rumour is untrue.

'In Aristotle's opinion,' said the most reliable of his biographers, 'the wise man should fall in love, take part in politics and live with a king.' The remark, if authentic, suggests that the Macedonian visit should have made a happy memory. Critics complained that Aristotle had gone to live in a 'home of mud and slime', an allusion to Pella's lakeside site, but before long Alexander and his friends were sent to the lowland town of Mieza where they could learn in a peaceful retreat of grottoes and shaded walks, believed to be sacred in the nymphs; traces of their school surroundings have recently been found near modem Naoussa, but how long this interlude lasted and how continuously the boys were taught is far from certain. After two yean, Alexander became involved in government business, and although Aristotle is known to have been in Macedonia the following summer, it may no longer have been as a tutor.

Whether briefly or not, Alexander spent these school hours with one of the most tireless and wide-ranging minds which has ever lived. Nowadays Aristotle is remembered as a philosopher, but apart from his philosophical works he also wrote books on the constitutions of 158 different states, edited a list of the victors in the games at Delphi, discussed music and medicine, astronomy, magnets and optics, made notes on Homer, analysed rhetoric, outlined the forms of poetry, considered the irrational sides of man's nature, set zoology on a properly experimental course in a compendious series of masterpieces whose facts become art through the love of a rare observer of nature; he was intrigued by bees and he began the study of embryology, although the dissection of human corpses was forbidden and his only opportunity was to procure and examine an aborted foetus. The contact between Greece's greatest brain and her greatest conqueror is irresistible, and their mutual influence has occupied the imagination ever since.

'The young man', Aristotle wrote, 'is not a proper audience for political science; he has no experience of life, and because he still follows his emotions, he will only listen to no purpose, uselessly.' There speaks, surely, a man who had tried philosophy on Alexander and failed, for there is little evidence that Aristotle influenced Alexander either in his political aims or his methods. He did, however, write pamphlets for him, perhaps on request, although none survives to be dated: their titles, On Kingship, In Praise of Colonies,and possibly, too, Alexander's Assemblyand The Glories of Riches,seem valid themes for a man who would become the richest king and the most prolific city-founder in the world, but Aristotle had already shown himself well able to flatter his patrons, and these works may have complimented Alexander's achievements rather than advised him to new ideas. Much has been made of Aristotle's supposed advice to 'treat the barbarians as plants and animals', but the advice may be fictitious. Although he did take the common view of his Greek contemporaries that Greek culture was superior to the ways of the barbarian cast, he cannot be condemned as a thoroughgoing racist; he was interested in Oriental religion and he praised very highly the constitution by which the Carthaginians were governed. When Alexander appointed Orientals to high positions in his empire, it is often said that practice had shown him the narrowness of his tutor's views on foreigners; their differences are not so very marked. Aristotle's political thought was formed from life in a Greek city, and it was these same Greek cities that his pupil planted from the Nile to the slopes of the Himalayas, where they lasted and mattered far longer than any age of kingship whose supposed importance Aristotle is often criticized for failing to anticipate. Not only through his cities, Alexander remained a Greek by culture in the world of the east, and although politics and friendship caused him to include Orientals in his Empire, he never took to Persian religion and may never have learnt an eastern language fluently.

Though politics were not at issue, a boy could not help learning curiosity from Aristotle, and to fourteen-year-old Alexander, he would seem less the abstract philosopher than the man who knew the ways of a cuttlefish, who could tell why wrynecks had a tongue or how hedgehogs would mate standing up, who had practised vivisection on a tortoise and had described the life cycle of an Aegean mosquito. Medicine, animals, the lie of the land and the shape of the seas; these were interests which Aristotle could communicate and Philip had already instanced, and each was a part of adult Alexander. He prescribed cures for snakebite to his friends, he suggested that a new strain of cattle should be shipped from India to Macedonia: he shared his father's interest in drainage and irrigation and the reclaiming of waste land; his surveyors paced out the roads in Asia, and his fleet was detailed to explore the Caspian Sea and the Indian ocean; his treasurer experimented with European plants in a Babylonian garden, and thanks to the expedition's findings, Aristotle's most intelligent pupil could include the banyan, the cinnamon and a bush of myrrh in books which mark the beginnings of botany. Alexander was more than a man of ambition and toughness; he had the wide armoury of interests of a man of curiosity, and in the days at Mieza there had been matter enough to arouse them. 'The only philosopher', a friend referred to him politely, 'whom I have ever seen in arms.'

To Aristotle the meeting may have seemed more irksome. The young, he wrote, are at the mercy of their changeable desires. They are passionate and quick tempered, they follow their impulses: they are ruled by their emotions. They strive for honour, especially for victory, and desire them both much more than money. They are simple-natured and trusting, because they have not seen otherwise. Their hopes fly as high as a drunkard's, their memories are short.

They are brave but conventional and therefore easily abashed. Unchastened by life, they prefer the noble to the useful: their errors are on the grand scale, bora of excess. They like laughter, they pity a man because they always believe the best of him ... unlike the old, they think they know it all already.

Behind such a confident analysis, there must be memories of Alexander and his fellow pupils. 'A child must be punished ...': 'the young do not keep quiet of their own accord', wrote Aristotle, 'but education serves as a rattle to distract the older children,' Discipline, it seems, was none too easy at Mieza.

Alexander was not his only Macedonian pupil. Aristotle began a friendship with Antipater, a man whose varied intelligence is easily forgotten, and Antipater's sons would have come for lessons at Mieza; so would the royal pages, and perhaps also Hephaistion, son of Amyntor to whom Aristotle dedicated a volume of letters. Hephaistion was the man whom Alexander loved, and for the rest of their lives their relationship remained as intimate as it is now irrecoverable: Alexander was only defeated once, the Cynic philosophers said long after his death, and that was by Hephaistion's thighs. There is only one statue that has claims to be of him; short-haired and long-nosed, he does not look unduly impressive, but looks may not have been his attraction. Philip had been away on too many campaigns to devote much time in person to his son and it is not always fanciful to explain the homosexuality of Greek young men as a son's need to replace an absent or indifferent father with an older lover. Hephaistion's age is not known and its discovery could put their relationship in an unexpected light: he may even have been the older of the two, like the Homeric hero with whom contemporaries compared him, an older Patroclus to Alexander's Achilles.