NEW YORK — One of the most important men you probably never heard of died July 17. Immersed in a bustle of events that no one will remember tomorrow, we tend to pay less attention to people who take on the issues of eternity — philosophers, moralists, sages who try to turn our minds to higher things.

Yet, in the long run, it is the latter who matter most, and their importance persists when other preoccupations turn out to be transitory. Such men and women change the world around them, even if others do not see it until much later.

Leszek Kolakowski was one of these people. He was a world-renowned philosopher, a professor at great universities — Oxford, Yale, Chicago — and someone who was respected and admired by his colleagues around the world. He wrote about Spinoza, the theological controversies of 17th-century Holland, and other esoteric subjects.