Throughout February, Quentin Skinner, regius professor of modern history at Cambridge, delivered the Ford's Lectures in British History under the title of "Freedom, Representation and Revolution, 1603-51". In the 17th century, according to Skinner, a particular view of freedom gained ground in England. Our liberty, to be true liberty, must be based on more than our ability to exercise our rights and liberties without interference from a discretionary power. (That, according to Skinner, is merely negative liberty.) It must rather be based on our having the status or standing of independent persons, not subject to another's will.
This not so innocent distinction helped cause the English civil war of 1642-51, and the new view of liberty legitimised the setting up of the English Republic. It was despatched in the counter-revolution; the version of freedom we have inherited is that negative, counter-revolutionary one, enshrined in Thomas Hobbes's Leviathan (1651). Our Leviathan is the monarch, to whom we are still beholden for our rights and liberties. This quite unjustifiable state of affairs becomes a lot less remote in applied terms: under her representative Tony Blair, according to the mildly spoken Skinner, our executive is not nearly responsible enough to the legislative. It is, in effect, an elected dictatorship.
When the feeling persists in a democracy, as it does in ours, that we are not truly free, a revival of the view of those 17th-century critics of the crown is overdue, though we should perhaps be careful how we understand our loss of freedom. We inhabit a democracy, yet our expectations have nearly ceased to be of a democratic kind. They are more to do with economic mobility.
The novel has been predicated on its involvement with individual, often political, freedom ever since it lost its religious sense, roughly a century ago. Here one tends to think of Sartre and Camus, and their conspicuously impractical agenda. In fact, by the 1930s, British novelists were way ahead of European existentialists. Freedom has seldom been more coherently and excitingly explored than in the British thrillers of that decade. Graham Greene's It's a Battlefield (1934) and England Made Me (1935) are key works; so are the pre-war novels of Eric Ambler, Uncommon Danger (1937), The Mask of Dimitrios (1939) and Journey into Fear (1940).
The Thirties thriller, with its protagonist cut loose from society, operated a readily understandable code that placed him in a rapidly mutating equation of good and evil.
The ordinary heroes of Ambler's fiction - stringers, writers on holiday, language teachers, stateless persons, all ensnared accidentally and resentfully in a world of menace - are psychologically convincing. Ambler was among the first to notice that glace-haired foreign spies were not always villains. His Russians, for instance, were often sympathetic; it was the agents of capitalism who had to be watched. (Ian Fleming's James Bond fails as a seeker of freedom: he is merely the agent of Leviathan.)
Ambler's novels are prophetic. In his second, Uncommon Danger, a freelance hack named Kenton finds himself up against agents of the Pan-Eurasian Petroleum Company, men who will not stop at murder to destabilise the Romanian government and gain control of the Bessarabian oilfields. In The Mask of Dimitrios, his hero Latimer remarks that "Good Business and Bad Business were the elements of the new theology". What Ambler had identified was a new field of conflict that would determine how free we are: not personal-patriotic, but personal-economic. To his heroes, dignity - and therefore freedom - lies in discovering that the world is dominated more by financial interests than political, and that accepting the smallest amount of cash for the wrong motive can relieve you of your honour. In person, these beliefs turned Ambler into an uncomplicated English anarchist.
When I spoke to him, shortly before his death in 1998, he said: "I don't really think I believe in democracy. Except in wartime, when it's in short supply." Ambler's natural successor, the only thriller writer of any consequence who is interested in freedom, or in the importance of the human act, is James Buchan. In a series of potent, complex novels, he has written about the cold war (Heart's Journey in Winter), the City of London (High Latitudes) and post-revolutionary Iran (A Good Place to Die). In this last book, the hero John Pitt is taken as a spy, tortured, then released to fight as the last and most useless conscript against Saddam's army. Buchan's story, in the ideal tradition of the thriller, is a Bildungsroman that turns Pitt from a spoilt, dreamy youth into a man of humanity, battered and improved by experience.
There, perhaps, lies the reverse of Professor Skinner's coin. For us 21st-century westerners, enjoying both unprecedented material wealth and an ideological passivity originating in our unwillingness to disturb that level of comfort, it may take another war to rediscover what true liberty means. Or, at least, another English revolution.