“The fox knows many things, but the hedgehog knows one big thing.” When Isaiah Berlin, as a young Oxford don in the late 1930s, first encountered this tantalising fragment of verse by the 7th-century BC Greek poet Archilochus, it became an entertaining way by which Berlin and his circle could categorise their friends: as hedgehogs or foxes. However, this mysterious shard of wisdom stuck in Berlin’s mind and eventually became the animating principle for an extraordinary essay on Tolstoy, dictated in the course of two days, and originally entitled Lev Tolstoy’s Historical Scepticism. (It was the publisher George Weidenfeld who suggested the substitution.) As well as interrogating the text of War and Peace, Berlin explored the fundamental distinction that exists between those who are fascinated by the infinite variety of things (foxes) and those who relate everything to a central, all-embracing system (hedgehogs).

By then, and in subsequent critical discourse, the division of humanity into hedgehogs and foxes had become not only a witty means of classification, but also an existential way of confronting reality. Foxes, for instance, will come to understand that they know many things, that a coherent worldview is probably beyond them and that they must be reconciled to the limits of what they know. In his life of Isaiah Berlin, the biographer Michael Ignatieff quotes Berlin thus: “We are part of a larger scheme of things than we can understand; we ourselves live in this whole and by it, and are wise only in the measure to which we make our peace with it.”

The distinction between the pluralistic fox and the single-minded hedgehog has become a staple of cultural analysis

Berlin’s hedgehog, by contrast, never makes peace with the world and remains unreconciled. His or her purpose is to know one big thing and, in Ignatieff’s words, “strive without ceasing to give reality a unifying shape. Foxes settle for what they know and may live happy lives. Hedgehogs will not settle and their lives may not be happy.”

Berlin’s famous essay, however, is not about wildlife. Addressing the supreme creative artist’s intellectual personality, he begins with an act of division, describing Dante, Pascal, Ibsen and Proust (inter alia) as hedgehogs and Shakespeare, Herodotus, Aristotle, Montaigne, Balzac, Goethe and Joyce as foxes.

From here, passing through a catalogue of great Russian writers – Pushkin, Dostoevsky, Turgenev, Chekhov and Gogol – Berlin arrives at the curious case of Count Lev Nikolayevich Tolstoy and confesses himself to be baffled. Ask whether Tolstoy’s ”vision is of one or of many, whether he is of a single substance or compounded of heterogenous elements” and, he admits, “there is no clear or immediate answer”.

Here, The Hedgehog and the Fox becomes an essay about Tolstoy’s philosophy of art and history (as expressed in War and Peace), a dazzling tour de force of fewer than a hundred pages. It was acclaimed from the first. “This little book,”wrote the Observer, “is so entertaining as well as acute that the reader hardly notices that it is learned too.” Across the Atlantic, the New York Times declared: “Not only does Mr Berlin command all the materials of erudition, literary and philosophical, for his task, but he has a deep and subtle feeling for the puzzle of Tolstoy’s personality, and he writes throughout with a wonderful eloquence.”

In correspondence with the great American critic Edmund Wilson, Berlin summarised his essay quite simply thus: “Tolstoy I maintain was by nature and gifts a fox who terribly believed in hedgehogs and wished to vivisect himself into one. Hence the crack inside him which everyone knows.” This “crack” is universal: humanity will always be reconciled to life as it is while, at the same time, longing for a simple, unitary truth, underlying existence, that provides a deep and consoling explanation.

The heroism of the hedgehog is that he or she rejects limitations and will probably never be reconciled to quotidian restriction. As Ignatieff has written, Tolstoy was contemptuous of all kinds of doctrine, both religious and secular, yet could never quite give up on the possibility of an ultimate explanation. “Tolstoy’s sense of reality,” writes Berlin, “was until the end too devastating to be compatible with any moral ideal which he was able to construct out of the fragments into which his intellect shivered the world, and he dedicated all of his vast strength of mind and will to the lifelong denial of this fact.”

The distinction between the pluralistic fox and the single-minded hedgehog has become a staple of modern cultural analysis. The ultimate accolade: Berlin’s brilliant exploitation of the concept has also inspired parody. In Punch (24 February 1954), John Bowle, with apologies to Edward Lear, divided the world into “owls” and “pussycats”, the former “wise, ghostly and detached”, the latter “round, fluffy and predacious”.

Berlin’s great essay endures because it is a rhetorical masterpiece, an intellectual firework display by a modern master, a brilliant investigation of a great writer and his work and perhaps because almost everyone is divided between living like foxes or hedgehogs. Berlin, who later said: “I am very sorry to have called my own book The Hedgehog and the Fox. I wish I hadn’t now”, ultimately accepted that he was “probably a fox”.

A signature sentence

“There exists a great chasm between those, on one side, who relate everything to a single central vision, one system, less or more coherent or articulate, in terms of which they understand, think and feel – a single, universal, organising principle in terms of which alone all that they are and say has significance – and, on the other side, those who pursue many ends, often unrelated and even contradictory, connected, if at all, only in some de facto way, for some psychological or physiological cause, related to no moral or aesthetic principle.”

Three to compare

George Steiner: Tolstoy or Dostoevsky, An Essay in Contrast (1960)

Isaiah Berlin: Against The Current, Essays in the History of Ideas (1979)

Edmund Wilson: The Fifties: From Notebooks and Diaries of the Period, ed Leon Edel (1986)

The Hedgehog and the Fox is available from W&N (£8.99). Click here to order a copy for £7.37