As part of a seminar on historiography I had to read Sidney Hook's book with this title. Still have the paperback somewhere in the house, and I can remember the crimson cover, but not anything of its contents.
The issue is and was whether the individual can influence the course of history. The answer I give now, whether or not it represents Hook's conclusions: it depends, sometimes "yes", sometimes "no".
It partly depends on the level of analysis. A story today in the Post on the death and burial of a WWII paratrooper, who fought heroically and was part of the force liberating a slave labor/concentration camp, where he formed a connection with a 17-year old inmate. He began working for peace. Did he change the world? No,
Gorbachev died the other day--he changed history. You can safely say the Cold War would not have ended in the way it did if any other communist leader had been in office.