The most energetic workers I have encountered in my world travels are the vegetarian miners of Chile.

In my simplicity, I remember wondering why every gentleman did not become an ornithologist.

It may be conceit, but I believe the subject will interest the public, and I am sure that the views are original.

For I am well aware that scarcely a single point is discussed in this volume on which facts cannot be adduced, often apparently leading to conclusions directly opposite to those at which I have arrived. A fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question.

Man, wonderful man, must collapse, into nature's cauldron, he is no deity, he is no exception.

Free will is to mind what chance is to matter.

Whenever I have found that I have blundered, or that my work has been imperfected, and when I have been contemptuously criticised, and even when I have been overpraised, so that I have felt mortified, it has been my greatest comfort to say hundreds of times to myself that 'I have worked as hard as I could, and no man can do more than this.'