Signs of the master spirit : Richard Ollard admires the forthright erud ition that fills the letters of Thomas Hobbes : The Correspondence of Thomas Ho bbes Ed Noel Malcolm Clarendon Press £20

The historical alarm clock of the 17th century seems to have had something wrong with it. So many of its greatest figures, in England at least, seem only to have woken to their true vocation when life was well into its afternoon. Cromwell is the m ost obvious example, both as soldier and statesman. What about Milton, turning to epic poetry in what was then old age? Hobbes is surely the supreme example. His masterpiece, in a branch of study that he had not even entered until he was middle-aged, bur st onthe world virtually unheralded, when he was 63.

What had he been doing all these years? We know he cannot by his very nature have been idle. His was "A working head" in Aubrey's telling phrase. His early brilliance as a classical scholar had secured him a tutorship that was to ripen into a lifelong family connection with the Earls of Devonshire. Chatsworth and Hardwick with their libraries, and the grand tours with his young charges that were to bring him the acquaintance of the leading minds of Europe from Galileo down, all contributed to the enrichment of a mind of exceptional fertility.

And so, it most interestingly appears, did intercourse with the Cavendish family. Those of us who have thought of William Cavendish, Earl of Newcastle, as the Captain Mark Phillips of the 17th century should read Hobbes's letters to him. In 1633 he bought him a copy of Galileo's Dialogue. In Paris in the same year he combined inspecting a dressage horse with scientific discussion. The freedom of their relationship is summarised in Hobbes's own words: "though I honour you as my lord, yet my love to you is just of ye same nature that it is to Mr Payne [a scientist, soon to return to Oxford, but then in the Earl's service] bred out of private talk, without regard to your purse".

The same forthrightness is even more remarkably displayed in a letter to the 18-year-old Charles Cavendish whose brilliant career was to be cut short in the first year of the Civil War. Hobbes warns him against sarcasm and tells him how to behave like a gentleman: "To encourage inferiours, to be cheerful with ones equals and superiors, to pardon the follies of them one converseth withall, and to help men, that have fallen into ye danger of being laught at, these are signes of noblenesse and of the master spirit."

The charm of the young royalist officer and his popularity with his men, both well attested, suggest that these words fell on good ground. They are the more interesting as coming from the least sententious of men, indeed one generally regarded as a cynicand a mocker.

It is clear from these two superbly edited volumes that Hobbes recognised his own commanding stature. "The Leviathan," wrote Michael Oakeshott, "is the greatest, perhaps the sole, masterpiece of political philosophy written in the English language." Its author would placidly have acknowledged his assent. Even more remarkably, so would the leading scholars of both the left and the right today.

Yet for all his eminence and for all the extraordinary span of his life - he was born in 1588 and died, still in full possession of his faculties, in 1679 - it is surprising how difficult it is to see him in the round. On the evidence of Noel Malcolm's editorship of these volumes his forthcoming biography should go as far as intelligence and sympathy and erudition can take us.

Hitherto much the most illuminating description of him has been by his friend John Aubrey. That and the painting in the National Portrait Gallery both convey the geniality and wit that must have made him such enchanting company. But the engraving of him reproduced on the back of the jacket emphasises the sternness, the force, the steel that overcame so timorous a temperament and swept it through a dangerous and violent age to such avowals of horrifying and alarming originality.

Apart from Aubrey, Hobbes hardly figures in the main contemporary accounts of Restoration England. He is not even mentioned in Pepys. He is just mentioned in Evelyn, who called on him in Paris during the Interregnum and again in London after his return.

On both occasions Evelyn claims long friendship but he says nothing about him and certainly did not share his views on politics and religion. Clarendon knew him before the Civil War as a fellow guest of Lord Falkland at Great Tew. They met again in Pariswhen Hobbes was mathematics tutor to the exiled Prince of Wales and it was Clarendon to whom Hobbes showed the manuscript of Leviathan before publication. Clarendon's instant disapproval strengthened with the years and led him shortly before his death to write a powerful critique which was published posthumously.

Hobbes's surviving English correspondence, though often lively, is comparatively small beer. There are no exchanges with Selden or Ben Jonson, both of whom he knew. There is far too much about his tedious squabbles with mathematicians such as Dr Wallis who were better versed in their subject than he. For all his deserved reputation as a savant of European stature Hobbes could descend to the meanest pettinesses of academic disputation.

In his European correspondence, on the other hand, he is courteous, learned, acute and even, rarest of his virtues, humble. Marin Mersenne, whose cell in the Palais Royal seems to have been the clearing house of early modern scientific ideas, features prominently, as does the more worldly and adventurous Samuel Sorbiere. The great bulk was with a circle of highly educated Huguenots from the Bordelais, whose careers and personal histories Noel Malcolm has teased out with exemplary editorial patience. The se men were chiefly involved in the translation and publication of Hobbes's works. It was through them that he came on to the list of the great Dutch publisher, Blaeu, now largely known for his sumptuous atlases.

Hobbes's letter to Samuel Sorbiere written in Latin from Paris in May 1646, shows that he had mastered the essentials of learned authorship. He emphasises the importance of what are now called in the trade "advance quotes". He warns against the surly jealousy of tenured academics. "For their public reputation demands that in the subject which they teach no one should have discovered anything which they have not already discovered".

The fluency and elegance of this translation is a fair sample of Noel Malcolm's skill. He has rounded off his Herculean labours with a biographical register that will be of value to all students of 17th-century culture and indispensable to anyone interested in Hobbes.