The world has changed irrevocably in the last century. Fifty years ago, it looked completely different; and the way the world looked to the great thinkers of the time still holds surprises. J. Robert Oppenheimer helped to invent the bomb that was dropped on Nagasaki and Hiroshima, which ultimately changed international politics forever. Northrop Frye took a new and challenging look at Canada in the changing international world. And Edward Togo Salmon understood the rise and fall of empire like nobody else. Who else to remind us of the complicated world in the cold-war period, and to look forward to the challenges of the future? We are that future, and looking back to their thinking is very worthwhile. Drawn from a high-profile series of lectures given at McMaster University from 1956 to the present, these three lectures were chosen for their fascinating reflections on the human world, past, present, and future. Take a whirlwind tour of the Roman Empire, find out about physics from Isaac Newton to the splitting of the atom, and consider Canada's position as it stood poised to enter a new modern century. An engaging introduction by Professor Jonathan Hart gives all that background you need to enjoy these explorations of science, culture, and empire in a rapidly changing world as it looked some fifty years ago to three brilliant thinkers.