To all the world he was the man of violence, half animal and half demon; but to her he always remained the little wilful boy of her own girlhood, the child who had clung to her hand. Evil indeed is the man who has not one woman to mourn him.

It is of the highest importance in the art of detection to be able to recognise out of a number of facts which are incidental and which are vital.

I had hardly expected so dolichocephalic a skull or such well-marked supra-orbital development. Would you have any objection to my running my finger along your parietal fissure? A cast of your skull, sir, until the original is available, would be an ornament to any anthropological museum. It is not my intention to be fulsome, but I confess that I covet your skull.

Our ideas must be as broad as Nature if they are to interpret Nature.

"I should have more faith," he said; "I ought to know by this time that when a fact appears opposed to a long train of deductions it invariably proves to be capable of bearing some other interpretation."

He seems to have declared war on the King’s English as well as on the English king.

At the moment our human world is based on the suffering and destruction of millions of non-humans. To perceive this and to do something to change it in personal and public ways is to undergo a change of perception akin to a religious conversion. Nothing can ever be seen in quite the same way again because once you have admitted the terror and pain of other species you will, unless you resist conversion, be always aware of the endless permutations of suffering that support our society.