Book excerpt: First published in 2006. The ambitious role cast for scientists in public affairs has been matched by an equal coyness on the part of scientists to play it. Yet in spite of themselves, they have been virtually dragged on to the political stage because of their 'collectivities' - groups formed over the last four centuries often more fugitive than institutional - which have helped modify the human environment, thereby enabling men to emancipate themselves from the tyranny of the present and plan for the future. The byproducts of such plans, from the great botanical gardens to the seed beds of physical scientists like the Ecole Polytechnique, have also incubated further ideas about the relation of science and society that are ecumenical in scope. Indeed the positivist overtones of the Polytechnique herald the transition from platocracy to technocracy, for the technical intelligentsia trained its German, Russian and American counterparts have effected a quasi-religious synthesis of physics and politics. In this 'planning' was the central theme. The social history of such planning (with the concomitant views on the social organisation of science) is the subject of the book Pressurising it is the conviction that " we can identify a particular thing only by pointing to the various things it successively was before it became that particular thing that it will presently cease to be", and the story, which begins four hundred years ago and ends in 1964.