[1] He is commemorated by the annual Thewlis Lecture on Gerontology and Geriatrics, established at the University of Rhode Island.
[3] Thewlis was born on December 4, 1889, in Wakefield, Rhode Island, the son of James E. Thewlis and Viola (née Wilcox),[4] and received his MD from the Bowdoin Medical School of Maine in 1911.
[5][6] He married Miss Christiane Cherfils (1895 – 1978[7]) of Paris, France on December 10, 1919, and they had a son, Harold, who became a professor of politics at University of Rhode Island.
[8] Thewlis was one of the few physicians to take note of Ignatz Leo Nascher's 1914 book, Geriatrics: The Diseases of Old Age and Their Treatment, and devoted his life's work to care of the elderly and research into the diseases of old age.
Thewlis was also an accomplished amateur magician,[10] and a member of the International Brotherhood of Magicians:[4] he recommended the practice of conjuring tricks to keep the mind and hands supple.