Arts and sciences in one and the same century have arrived at great perfection; and no wonder, since every age has a kind of universal genius, which inclines those that live in it to some particular studies; the work then, being pushed on by many hands, must go forward.

However, the small probability of a similar encounter [of the earth with a comet], can become very great in adding up over a huge sequence of centuries. It is easy to picture to oneself the effects of this impact upon the Earth. The axis and the motion of rotation changed; the seas abandoning their old position to throw themselves toward the new equator; a large part of men and animals drowned in this universal deluge, or destroyed by the violent tremor imparted to the terrestrial globe.

If the great story of the last century was the conflict among various political ideologies—communism, fascism and democracy—then the great narrative of this century will be the changes wrought by astonishing scientific breakthroughs

In the past century, there were more changes than in the previous thousand years. The new century will see changes that will dwarf those of the last.
Referring to the 19th and 20th centuries.

John Dalton's records, carefully preserved for a century, were destroyed during the World War II bombing of Manchester. It is not only the living who are killed in war.

Nothing holds me ... I will indulge in my sacred fury; I will triumph over mankind by the honest confession that I have stolen the golden vases of the Egyptians to build up a tabernacle for my God, far away from the confines of Egypt. If you forgive me, I rejoice ; if you are angry, I can bear it. The die is cast; the book is written, to be read either now or by posterity, I care not which. It may well wait a century for a reader, as God has waited six thousand years for an observer.

The improvement of forest trees is the work of centuries. So much more the reason for beginning now.

Truths are immortal, my dear friend; they are immortal like God! What we call a falsity is like a fruit; it has a certain number of days; it is bound to decay. Whereas, what we call truth is like gold; days, months, even centuries can hide gold, can overlook it but they can never make it decay.