Peter Mark Roget, the British physician, inventor, scientist, and lexicographer who late in life published his enduring magnum opus Roget’s Thesaurus, died on September 12, 1869, at the age of 90, while on vacation in the Malvern Hills.
Roget was a remarkable Victorian figure with wide interests and a long list of medical and scientific achievements even before he became a household word in 1852 after publishing his Thesaurus at the age of 73. (Roget himself has by now basically become a synonym for Thesaurus.)
The son of a Geneva-born pastor, Roget grew up in London’s tight-knit French-speaking Huguenot Protestant community.
His family, unfortunately, had a strong strain of mental illness on his mother’s side. His grandmother, mother, sister, and daughter all suffered from versions of paranoia, schizophrenia or depression.
After his father’s death, when Roget was only four years old, he was taken under the wing of his mother’s brother, Samuel Romilly, a prominent member of Parliament who led anti-slavery and pro civil rights campaigns.
Romilly also suffered from depression and died in Roget’s arms by suicide, having cut his throat shortly after his wife’s death.
Roget himself suffered from life-long depression and paranoia. He also seems to have suffered from Obsessive Compulsive Disorder, as shown by his ritual counting and obsession with symmetry.
Some people suggest that were he alive today Roget might be considered to be on the high-functioning end of the Asperger’s Syndrome spectrum.
Making lists and elaborate cross-classifications became an important coping mechanism for Roget from childhood on. It helped him combat his darker periods, and allowed him to make order out of the chaos around him.
His obsessions with classification and order were also assets in Roget’s medical and scientific careers.
Roget played a part in the invention of the slide rule, which uses his algorithm to calculate the roots and powers of numbers.
He had an interest in the study of optics, and his paper showing that the human eye can retain images for up to 16 seconds, despite interuptions, helped in the later invention of motion picture photography. (He also improved the kaleidoscope.)
He retired from his medical and scientific pursuits at the age of 60 to re-dedicate himself to the enormous undertaking that he had first begun in his 20s — compiling his Thesaurus, a cross-referenced list of related words and synonyms.
He finally published his book, under the full title Thesaurus of English Words and Phrases, Classified and Arranged so as to Facilitate the Expression of Ideas and Assist in Literary Composition, 12 years later.
It was an immediate success and went through 28 printings by the time of Roget’s death. It hasn’t been out of print since then and by its 150th anniversary in 2002 had sold 32 million copies.
The Thesaurus was regularly updated for years by Roget’s son and grandson and continues to grow with each successive edition.
The calculator killed the slide-rule in the 1970s, but Roget’s Thesaurus continues to live on even in the Internet era.