I am actually weary of telling people that I do not pretend to adduce [direct] evidence of one species changing into another, but I believe that this view is in the main correct, because so many phenomena can thus be grouped end explained.

I have deeply regretted that I did not proceed far enough at least to understand something of the great leading principles of mathematics, for men thus endowed seem to have an extra sense.

The voyage of the Beagle has been by far the most important event in my life and has determined my whole career; yet it depended on so small a circumstance as my uncle offering to drive me 30 miles to Shrewsbury, which few uncles would have done, and on such a trifle as the shape of my nose.

Multiply, vary, let the strongest live and the weakest die.

Blushing is the most peculiar and the most human of all expressions. Monkeys redden from passion, but it would require an overwhelming amount of evidence to make us believe that any animal could blush.

Nothing exists for itself alone, but only in relation to other forms of life

[Alexander von Humboldt was the] greatest scientific traveller who ever lived.