Why is The Origin of Species such a great book? First of all, because it convincingly demonstrates the fact of evolution: it provides a vast and well-chosen body of evidence showing that existing animals and plants cannot have been separately created in their present forms, but must have evolved from earlier forms by slow transformation.

There is grandeur in this view of life... [in which] endless forms most beautiful and most wonderful have been, and are being, evolved.

In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.

And thus, the forms of life throughout the universe become divided into groups subordinate to groups.

For forms existing in larger numbers will always have a better chance, within any given period, of presenting further favourable variations for natural selection to seize on, than will the rarer forms which exist in lesser numbers.

Man could no longer be regarded as the Lord of Creation, a being apart from the rest of nature. He was merely the representative of one among many Families of the order Primates in the class Mammalia.