This volume concerns education of the physical, moral and spiritual nature, in addition to contemplating what knowledge is worth. Herbert Spencer was the pre-eminent philosopher and sociologist of the Victorian era in Britain; his views on "social Darwinism" are largely discredited today, but still latent.

It is the end of the nineteenth century, and Sherlock Holmes, the world-famous detective, lives at 221B Baker Street in London. The great capital is a rainy, foggy city, where the police often have difficulty in catching criminals. Luckily, Holmes is there to help them, but only if a case is interesting enough.

Holmes is extremely intelligent, and intelligent people are often impatient with their friends. 'Think, Watson!' he says sharply to the good doctor, who is not as clever or as quick as he is. But he sometimes needs Dr Watson's help, and is grateful for it, especially in a dangerous situation.

Sir Arthur Ignatius Conan Doyle (22 May 1859 – 7 July 1930) was a Scottish writer and physician, most noted for his fictional stories about the detective Sherlock Holmes, which are generally considered milestones in the field of crime fiction.

He was a prolific writer whose other works include fantasy and science fiction stories, plays, romances, poetry, non-fiction and historical novels.