Nothing can be more improving to a young naturalist, than a journey in a distant country.

...all nature is perverse & will not do as I wish it.

It is a truly wonderful fact - the wonder of which we are apt to overlook from familiarity - that all animals and all plants throughout all time and space should be related to each other in group subordinate to group.

The most important factor in survival is neither intelligence nor strength but adaptability.

You ask about my opinion on vivisection. I quite agree that it is justifiable for real investigations on physiology; but not for mere damnable and detestable curiosity.

Freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science.

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.