Brian Barry was one of the most influential British political philosophers of the postwar era. He had been an academic wanderer, holding positions at the universities of Birmingham, Keele, Southampton, Oxford and Essex, before moving to posts in Canada and the US at British Columbia, Chicago and the California Institute of Technology.

After a short stay at the European University Institute, Florence, he returned to England to spend 11 years as professor of political science (1987-98) at the London School of Economics. There, perhaps, he found his true intellectual home as well as personal happiness in his second marriage, and in these years produced some of his most important work. His last post was as the Lieber Professor of Political Philosophy at Columbia University, New York.

Brian Barry was born in London in 1936 before moving as a child to Southampton. From grammar school there he went to take a first in philosophy, politics and economics at The Queen’s College, Oxford, before studying under H. L. A. Hart for his doctorate. Even before he achieved his doctorate he was awarded a post-doctoral fellowship by the Rockefeller Foundation, which he took at Harvard largely so that he could meet John Rawls, who was then at MIT.

In the event Rawls made less of an impression on Barry at that time than did Edward Banfield and Thomas Schelling whose courses on the economic approach to the study of politics and game theory respectively convinced him that political science could be a discipline in its own right, rather than simply contemporary history.

Barry’s DPhil was published as Political Argument in 1965. It argued that political philosophy could be about fundamental moral issues rather than the dry analysis of political concepts into which British political theory had largely fallen. And it also engaged in that process of political argument. The last two chapters evaluated ideas he had encountered while at Harvard.

His sustained critique of Pareto optimality — a situation in which economic resources cannot be re-allocated without someone being made worse off — as a fundamental justifying concept for constitutional provisions could, had more notice been taken, have destroyed new Right thinking before it had really begun.

Rawls’s A Theory of Justice, published six years later, revitalised political philosophy along precisely the lines argued for by Barry. Realising its importance, Barry wrote a book-length critique, Liberal Theory of Justice (1973), while travelling on a tramp steamer for three months.

Ironically, in his later works Barry can be seen as the foremost defender of Rawlsian liberal egalitarianism. In his Theories of Justice (1989) and Justice as Impartiality (1995) he provided the strongest defence of Rawls’s “difference principle” that constrains complete equality; and defended universalistic liberal principles of equality based on reasonable agreement.

In 2001 Barry published Culture and Equality, a sustained critique of multiculturalism. He realised that the universalistic principles of justice he defended could be institutionalised in different ways in different cultures, but those cultures had to remain cultures with their own ways of doing things — we cannot mix and match different conventions within a single polity. He argued that multicultural practices can coexist alongside each other only if they do not conflict at some fundamental moral level, and that some cultural practices are simply incompatible with liberalism and principles of equality.

His last book, Why Social Justice Matters (2005), was a coruscating critique of new Labour and left-leaning ideas around it. In recent years egalitarians have argued that egalitarian institutions must allow for individual responsibility and choice.

It was obvious to Barry that the ill health and deprivation of the poor were the fault of capitalism, regulators and government, and that assertions of individual responsibility thrust upon the suffering came loudest from those keen to avoid their own responsibility for society’s ills.

It is for these major works on justice along with myriad articles — some collected in his Democracy, Power and Justice: Essays in Political Theory (1989) — and for the training he provided for several generations of students that Barry will be academically remembered. His friends and colleagues will also remember the man. Sometimes ferocious, he could deflate the most erudite of arguments with a single quip. His ferocity was generated because he believed everything he wrote, about reason, about justice, about equality, about our duties to others now and in the future. If he was harsh on people at times it was because he cared: it mattered to him that the argument before him was wrong in some way; it mattered to him that misleading claims led society astray.

Academic writing was not simply a job or a game for him; it was a vocation, and a vocation that was urgent and important. He despised the hypocrisy he saw in some academics and politicians, and railed against inefficiency and stupidity which he saw, perhaps too often, all around him. But he was also generous in thought and deed, as generations of students and a wide circle of devoted friends can testify.

Barry was elected to fellowships of the American Academy of Arts and Sciences (1976) and the British Academy (1988). The Political Studies Association three times awarded him the W. J. M. Mackenzie prize for the best book published in the previous year, and acknowledged his lifetime achievement in 2000. He had been, indeed, a key player in the history of the PSA, helping to turn it from amateur club to professional organisation. He co-founded the British Journal of Political Science which remains the only general British politics journal of outstanding international quality.

His editorship of Ethics is credited with saving it as a top political philosophy journal. In 2001 he became the first, and to date the only, British winner of the Johan Skytte Prize in Political Science — the highest honour for a political scientist — recognising, in the words of the prize citation, “his profound contribution to normative political theory performed with passion as well as clarity in the grand tradition from Enlightenment”.

Barry suffered ill-health in his final years, after retiring from his post in New York in 2005 and returning to the UK. He is survived by his wife, Anni, by his first wife and his son.

Professor Brian Barry, philosopher and political scientist, was born on August 7, 1936. He died from a heart attack on March 10, 2009, aged 72