As long ago as 1784 Immanuel Kant showed incomparably just what Enlightenment is. It will never be possible in the same way to show anyone quite what the Enlightenment once was; but David Williams's collection of readings is scarcely one of the more compelling attempts to do so, not least because his 70-page introduction fails completely to pose any clear question, and is correspondingly ill placed to suggest clear answers to any.
The readings themselves, while being, as he says, necessarily arbitrary and incomplete, do at least present excerpts from a number of important texts - by, for example, Jean Barbeyrac, Jean-Jacques Burlamaqui, Friedrich Karl von Moser and Olympe de Gouges, among more familiar figures - that are not readily accessible to most students; and the brisk guidance provided on their provenance is reasonably clear and trustworthy. But the introduction itself is very vaguely organised, historically bland and desultory, and analytically relaxed to a fault.
As a historian of French literature, and an expert particularly on Voltaire, Condorcet and the feminism of the French Enlightenment, Williams has obvious qualifications for addressing the question of how students should conceive the Enlightenment and at least begin to try to gauge its significance. But he does not himself appear to have any coherent conception of what it was, or to anticipate that his readers may need specific assistance when they come to assess that significance.
What it was, to be sure, is in the first place a question for historians, and preferably for historians who combine the energy, intelligence and gusto of a Roy Porter with a somewhat more obsessive concern for analytic focus and clarity. But what it signified or signifies is a question for all of us, and one that still divides intellectual and political judgement today almost as sharply as it did in 1784.
A textbook on the Enlightenment bites off overwhelmingly more than it can hope to chew, and is thus far more threat than promise even in the first instance. It is brave to undertake one at all; but is hard to see how this one could give dependable educational guidance to any reader who seriously required it.
Janet Coleman's two-volume A History of Political Thought from the Greeks to the Renaissance is a very different offering. Coleman herself has an impressive international reputation as a medievalist, and she remains an agreeably compulsive scholar. But what really marks these two volumes out is her passionate and devoted commitment to teaching - and a level of devotion to her own university as a teaching institution.
These volumes cover the scholarship of the last four decades with considerable care and in an impeccably cosmopolitan manner. They also pay extensive attention to the somewhat over-reflexive intellectual and methodological preoccupations of the last few decades with historicising and relativising the cultural sources for the life of the mind in Britain today.
But Coleman has too strong an identity of her own - and too much to teach others - for her to have learned from all this merely a diffuse intellectual nervousness and insincerity.
She could scarcely be more at odds with the culture of assessment and servility that emanates from the Higher Education Funding Council, and she takes an ingenuous but heartening pride in the knowledge that her pupils have been listening, and responding, to her teaching with pleasure and excitement since before that culture was conjured into existence.
While her two volumes share a common preface, they are in other respects clearly just halves of a single whole, even if they could, as the publishers envisage, perfectly well be used independently of one another.
The first takes the reader through the political and social setting of ancient Greek thinking, through the ideas of Socrates, Plato, and Aristotle, to the Roman republic of Cicero, and the personal, episcopal, and intellectual adventures of St Augustine.
The second begins with a striking panorama of the institutional and imaginative matrix of medieval intellectual life, moves through the bracing intellectual efforts of St Thomas Aquinas, Marsilius of Padua, and William of Ockham, and closes with a thoughtful and illuminating depiction of the Italian background to Machiavelli's remarkable imaginative life, and a vivid defence of his claims to remain true to the historical experience and civilisation from which he came. The Machiavellian interpretation is particularly contentious, and in my view seriously underplays his zest for his own intellectual audacity. But it gains greatly in force from being juxtaposed with the sheer wealth of Coleman's analysis of Machiavelli's medieval antecedents, and her balanced presentation of some of the principal classical sources from which he drew so extensively.
Whatever else may be true about Machiavelli's ultimate judgement of what politics is and means, Coleman makes very clear that his thought as a whole was a self-conscious and painstaking commentary on the legacy of a culture that took the requirements for living well together with quite exceptional seriousness.
As Coleman herself emphasises, there remain quite strong national differences in construing the history of political ideas, and often differences not merely over the composition of the canon or cast list, but also over the range of contexts taken to be relevant, or the styles of analysis judged to be intellectually and professionally adequate. For all the geographical breadth of her own educational experience, Coleman's vision of the history of European political ideas is very much that of a British medievalist in its orientation and sense of location.
Her second volume overlaps with excellent recent textbooks like Joseph Canning's A History of Medieval Political Thought 300-1450 (1996) and Antony Black's Political Thought in Europe 1250-1450 (1992), not invariably to its advantage.
Her most striking comparative advantage comes from the depth of her personal engagement with the classical imaginative heritage that lay behind so much of the boldest and most penetrating of medieval social and political thinking.
Coleman herself sees the history of European political thinking more or less throughout as directly continuous with the individual question of how it is good or bad to live one's own life - and in that sense, perhaps rather gloriously, in the end fails to historicise it at all, since she has such pronounced views on the subject.
She is properly humble about the tangled history of greed and cruelty to which we are all heirs - what civilisation is not? But she is also a defiant partisan of Aristotle's vision of the good in living not merely with, but also in part consciously for, many, many other human beings with whom you regularly deal.
This is a historian's history of political thought, written for the edification of a generation of social scientists, who are professionally inoculated, with varying degrees of success, against that Aristotelian vision: a permanent one-woman cultural counter-revolution. It is also, in its second volume, the best single-volume history of medieval political thought to put into the hands of any intelligent and serious student.
In mode, the first volume has all the same virtues. But it is up against much stiffer and more extensive competition. It is not that single-volume "Histories of Ancient Political Thought" have recently proved an especially successful genre - for a variety of reasons, including the protracted American attempt to take the measure of the late Leo Strauss. It is simply that here the great texts have remained at the centre of a continuing tradition of hard thought, and at least intermittently deep feeling, for as long as our collective memory reaches.
Coleman has much of interest to tell her students or readers about Plato or Aristotle. But what she has to convey does not have the incisiveness or the intellectual allure of philosophers like Bernard Williams or Myles Burnyeat. In the end, it is simply tamer, less startling, and altogether less disruptive.
Reading Williams or Burnyeat, like reading Plato himself, you might always find yourself wondering whether you had seriously misjudged how to live your own life. Reading Coleman, probably not. What you certainly may find yourself wondering, however, is whether we have recently somewhat misjudged the requirements for educating each other together, and not least at university level.
Servility and assessment, of course, are both deeply Roman conceptions - as Roman as ruling other people and crushing the proudest of military opponents. But neither is one of our more enticing gifts from the ancient world. It is nice to think of Coleman militating against both of them, deploying the full resources of the tradition to do so, and unleashing these on grateful audiences within one of the leading citadels of British social science.
Coleman's History is a fine achievement and of clear use value throughout. It breathes the spirit of a very different epoch, while providing help for all of us who must deal, in our respective roles, with the ideas that it chronicles. In its second volume, it reaches appreciably higher; and what it achieves there is likely to last rather longer.
John Dunn is professor of political theory, University of Cambridge.
The Enlightenment: First edition
Editor - David Williams
ISBN - 0 521 56373 9 and 56490 5
Publisher - Cambridge University Press
Price - £42.50 and £15.95
Pages - 529