After five centuries of remarkable discovery science is still at its beginning - what we already know is but a tiny fraction of what we still have to understand. In this extraordinary book John Maddox, editor of Nature for 21 years, investigates how science will change the world and our place in it and what remains to be found out to make our outstanding of the world more complete. Each chapter will deal with a different field of science, describing in general language the problems now in the front of working scientists' minds and those lying at a greater distance ahead. As the book progresses, it will emerge that the problems still unsolved compare in their challenge with those now counted among the greatest triumphs of research and in their importance with the way in which five centuries of modern science have already given us an awesome glimpse of the world which we live in, of our competence and of our vulnerabililty.