It has been 25 years since Lord John Vaizey, the English economist and educationist passed away in July 1984. Today, Vaizey is almost a forgotten figure in modern British history and even more in the fields of political economy and economics of education where he first made his mark. His work is now rarely cited and, even in political histories of the Thatcher decade, or the travails of the Labour governments before then, his name rarely reappears. This paper reassesses his life, especially the last decade of his life when Vaizey, basked in the limelight, and enjoyed some of the glittering prizes. It was a decade when Vaizey took some major ideological turns, one of the most controversial being his decision to leave the Labour party after 30 years of membership. The paper revisits the reasons why Vaizey renounced democratic socialism, Keynesianism and, along with that, the beguiling promises of social science. It reflected his peculiar interest in political failure along with disillusionment in democratic socialism. The switch meant that this Cambridge-trained economist who described himself once as ‘a deeply flawed puritan, dedicated to work, self improvement, the cultivation of the intellect, goodness and truth’ had to convert, albeit reluctantly, to monetarism and ditch the post-war Keynesian consensus.