Born at Wisbech in Cambridgeshire, Godwin's family on both sides were middle-class people, and it was probably only as a joke that he, a stern political reformer and philosophical radical, attempted to trace his pedigree to a time before the Norman Conquest to the great earl, Godwine. Both parents (John and Anne Godwin) were strict Calvinists. His father, a Nonconformist minister, died young, and never inspired love or much regret in his son; but in spite of wide differences of opinion, tender affection always subsisted between William Godwin and his mother, until her death at an advanced age.

William Godwin was educated for his father's profession at Hoxton Academy, where he studied under Andrew Kippis the biographer and Dr Abraham Rees of the Cyclopaedia. He was at first more Calvinistic than his teachers, becoming a Sandemanian, or follower of John Glas, whom he describes as a celebrated north-country apostle who, after Calvin had "damned ninety-nine in a hundred of mankind, has contrived a scheme for damning ninety-nine in a hundred of the followers of Calvin."

He then acted as a minister at Ware, Stowmarket and Beaconsfield. At Stowmarket the teachings of the French philosophers were brought before him by a friend, Joseph Fawcet, who held strong republican opinions. He came to London in 1782, still nominally a minister, to regenerate society with his pen — a real enthusiast, who shrank theoretically from no conclusions from the premises which he laid down. He adopted the principles of the Encyclopaedists, and his own aim was the complete overthrow of all existing institutions, political, social and religious. He believed, however, that calm discussion was the only thing needful to carry every change, and from the beginning to the end of his career he deprecated every approach to violence. He was a philosophic radical in the strictest sense of the term.

His first published work was an anonymous Life of Lord Chatham (1783). Under the inappropriate title Sketches of History (1784), he published under his own name six sermons on the characters of Aaron, Hazael and Jesus, in which, though writing in the character of an orthodox Calvinist, he enunciates the proposition "God Himself has no right to be a tyrant." Introduced by Andrew Kippis, he began to write in 1785 for the Annual Register and other periodicals, producing also three novels now forgotten. The Sketches of English History written for the Annual Register from 1785 onward still deserves study. He joined a club called the "Revolutionists," and associated much with Lord Stanhope, Horne Tooke and Holcroft. His clerical character was now completely dropped.

In 1793, while the French Revolution was in full swing, Godwin published his great work on political science, Enquiry concerning Political Justice, and its Influence on General Virtue and Happiness. Political Justice was extremely influential in its time: after Burke and Paine, Godwin's was the most popular written response to the French Revolution. Prime Minister William Pitt famously said that there was no need to censor it, because at over £1 it was too costly for the average Englishman to buy. However, as was the practice at the time, numerous "corresponding societies" took up Political Justice, either sharing it or having it read to the illiterate members. Eventually, it sold over 4000 copies and brought literary fame to Godwin.

Godwin augmented the influence of the Political Justice with his publication of an equally popular novel, Things as They Are, or the Adventures of Caleb Williams, which tells the story of a servant who finds out a dark secret about Falkland, his aristocratic master and is forced to flee because of his knowledge. Caleb Williams is essentially the first thriller: Godwin wryly remarked that some readers were consuming in a night what took him over a year to write. Not the least of its merits is a portrait of the English justice system at the time and a prescient picture of domestic espionage.

Yet Godwin's strenuous Calvinism still obtains, if in secular form. At the conclusion of the novel, when Caleb Williams finally confronts Falkland, the encounter fatally wounds the Lord, who immediately admits the justness of Williams' cause. Far from feeling release or happiness, Williams only sees the destruction of someone who remains for him a noble, if fallen person. Implicitly, Caleb Williams ratifies Godwin's assertion that society must be reformed in order for individual behavior to be reformed, an emphasis that allies him more with Marxism and anarchism than liberalism.

Later, in response to a treason trial of some of his fellow English Jacobins, Godwin wrote Cursory Strictures on the Charge Delivered by Lord Chief Justice Eyre to the Grand Jury, October 2, 1794 where he forcefully argued that that the prosecution's concept of "constructive treason" allowed a judge to construe any behavior as treasonous. It paved the way for a major, but mostly moral, victory for the Jacobins, as they were acquitted.

However, Godwin's own reputation was eventually besmirched after 1798 by the conservative press, in part because he chose to write a candid biography of his dead wife, Mary Wollstonecraft, including accounts of her two suicide attempts and her affair with Gilbert Imlay, which resulted in the birth of Fanny Imlay. Godwin, consistent in his theory and stubborn in his practice, practically lived in secret for 30 years because of his reputation. However, in its influence, on writers like Shelley, Kropotkin, and others, Political Justice takes its place with Milton's Areopagitica, Locke's Essay on Education and Rousseau's Emile as an anarchist and libertarian text.

By the words "political justice" the author meant "the adoption of any principle of morality and truth into the practice of a community," and the work was therefore an inquiry into the principles of society, of government and of morals. For many years Godwin had been "satisfied that monarchy was a species of government unavoidably corrupt," and from desiring a government of the simplest construction, he gradually came to consider that "government by its very nature counteracts the improvement of original mind," confirming his beliefs as those that would later be widely recognized as anarchist.

Believing in the perfectibility of the race, that there are no innate principles, and therefore no original propensity to evil, he considered that "our virtues and our vices may be traced to the incidents which make the history of our lives, and if these incidents could be divested of every improper tendency, vice would be extirpated from the world." All control of man by man was more or less intolerable, and the day would come when each man, doing what seems right in his own eyes, would also be doing what is in fact best for the community, because all will be guided by principles of pure reason.

Such optimism combined with a strong empiricism to support Godwin's belief that the evil actions of men were solely reliant on the corrupting influence of social conditions, and that changing these conditions could remove the evil in man. This is similar to the ideas of his wife, Mary Wollstonecraft, concerning the shortcomings of women being down to their discouraging upbringings.

Godwin did not believe that all coercion and violence was immoral per se, as Bakunin and Tolstoy did, but rather recognised the need for government in the short term and hoped that the time would come when it would be unnecessary. Neither was he as extreme an egalitarian as most anarchists are, but he simply thought that discrimination on grounds other than ability was immoral; his moral case of saving the Archbishop of Canterbury before his mother from a burning house is seen as abhorrent by many egalitarians.

In 1798 Malthus wrote his An Essay on the Principle of Population partly in response to Godwin's views on the "perfectibility of society". Unlike Godwin, Malthus predicted impending doom from what he believed to be a geometrically rising world-wide population. While Godwin’s Political Justice acknowledged that an increase in the standard of living via his proposals could cause population pressures, he saw an obvious solution to avoiding such a crisis: “project a change in the structure of human action, if not of human nature, specifically the eclipsing of the desire for sex by the development of intellectual pleasures”. Indeed it was this “principle of population” that provoked Malthus’s Essay on the Principle of Population in 1978.

Godwin did not officially respond to Malthus’s for over twenty years. In 1820, Godwin published Of Population: An Enquiry Concerning the Power of Increase in the Numbers of Mankind, as a rebuttal to Malthus’s attack on Political Justice. Godwin refers to Malthus’s theory as a “house of cards” that Malthus “neither proves nor attempts to prove”.

Godwin’s main objection was Malthus’s sweeping ascription of the rate of population growth in America as a worldwide phenomenon. Godwin finds that such a proposition must be accepted solely as a matter faith on the part of Malthus’s reader. On the contrary, Godwin attested to the verifiable fact that much of the Old World was at a stand in population growth. Furthermore, Godwin believed that the abundance of uncultivated land and continued technological advances made fears of overpopulation even more unjustifiable.

In an era where many children did not survive to maturity, Godwin believed that for population to double every twenty-five years as Malthus asserted would require every married couple to have at least eight children. Although, Godwin himself was one of thirteen children, he did not observe the majority of couples having eight children. Godwin concludes his rebuttal with the following challenge: "In reality, if I had not taken up the pen with the express purpose of confuting all the errors of Mr Malthus’s book, and of endeavouring to introduce other principles, more cheering, more favourable to the best interests of mankind, and better prepared to resist the inroads of vice and misery, I might close my argument here, and lay down the pen with this brief remark, that, when this author shall have produced from any country, the United States of North America not excepted, a register of marriages and births, from which it shall appear that there are on an average eight births to a marriage, then, and not till then, can I have any just reason to admit his doctrine of the geometrical ratio.

While his work was considered unacceptably radical at the time, it is surprising how many of his radical ideas are now commonly accepted across the West. Examples include:

1. People should only be judged on their abilities.
2. War should only be allowed to protect a country's liberties or the liberties of another country.
3. Colonialism is immoral.
4. Democracy is more efficient than other forms of government, as it allows everyone to voice their opinion, rather than centralising power in a fallible monarch. However, majority rule places individual liberty of those in the minority in jeopardy.
5. Government close to the people is best.
6. Individuals should give to others in need.
7. Rehabilitation should be provided for criminals.
8. One should have a sphere of private judgement over issues that do not threaten the security of other people, as opposed to the legislated Christianity of his time.
9. Censorship prevents the truth from being recognised and should only be used when there is an immediate security risk.
10. His critique of state education is something that has not been widely accepted, except by libertarians. It also runs counter to Wollstonecraft's own proposal for state supported education in The Vindications of the Rights of Women.

All his radical reforms were to be done by discussion, and matured change resulting from discussion. Hence, while Godwin thoroughly approved of the philosophic schemes of the precursors of the Revolution, he was as far removed as Burke himself from agreeing with the way in which they were carried out. So logical and uncompromising a thinker as Godwin could not go far in the discussion of abstract questions without exciting the most lively opposition in matters of detailed opinion.

An affectionate son, and always ready to give some of his hard-earned income to more than one poor brother, he maintained that natural relationship had no claim on man, nor was gratitude to parents or benefactors any part of justice or virtue. In a day when the penal code was still extremely severe, he argued gravely against all punishments1, not only that of death. Property was to belong to those who most wanted it. However, he still saw a need for some respect for other people's belongings, as this was seen as part of their "right to private judgement", which he valued highly.

Note: Godwin did not call for the immediate end to punishment. He opposed the idea that it was a moral imperative to punish someone, which was the common view of his day, and rejected the religious laws interfering with one's personal life. He spoke of three justifications for punishment: deterrence, rehabilitation and security for the rest of society. He hoped that the day would come when there would be no need to punish on these grounds.