Photo source: Wikimedia Commons, John G. Murdoch
Charles Darwin (1809-1882) was an English biologist best known for his analysis of evolution and the theory of natural selection. Mahatma Gandhi said,
"Darwin for the greater part of his book On the Origin of Species, has simply massed fact upon fact without any theorising, and the only towards the end has formulated his conclusion which, because of sheer weight of testimony behind it, becomes almost irresistible." (Quoted in The Teachings of Mahatma Gandhi by Jag Parvesh)The rest of this post is some quotes from Darwin.
Natural selection
"...any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new modified form." (On the Origin of Species, 1859)
"I have called this principle, by which each slight variation, if useful, is preserved, by the term of natural selection, in order to mark its relation to man's power of selection." (On the Origin of Species, 1859)
"The expression often used by Herbert Spencer of the 'survival of the fittest' is more accurate and is sometimes equally convenient." (On the Origin of Species, 1859)
"...I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed by the Creator." (The Descent of Man, 1871)
Animal intelligence
"As I was lead to keep in my study during many months worms in pots filled with earth, I became interested in them, and wished to learn how far they acted consciously and how much mental power they displayed." (The Formation of Vegetable Mould through the Action of Worms, 1881)
"In this case, therefore, the worms judged with a considerable degree of correctness how best to draw the withered leaved of this foreign plant into their burrows; notwithstanding that they had to depart from the usual habit of avoiding the foot-stalk." (The Formation of Vegetable Mould through the Action of Worms, 1881)
"The lower animals, like man, manifestly feel pleasure and pain, happiness and misery... Even insects play together..." (The Descent of Man, 1871)