Lieutenant-Colonel Thomas Edward Knowles Stansfield, CBE (born 1862; died 19 February 1939) was a British pathologist of mental illness and medical officer.

Thomas Edward Knowles Stansfield was born in 1862,^[1] the son of Thomas Stansfield (1831–1908), of Langfield in Yorkshire, and his wife Hannah, daughter of William Knowles; he had a brother, William Knowles Stansfield (born 1856), of Roomfield, Todmorden.^[2] The family were well-established in the area, which straddled the Lancashire and Yorkshire borders, and were reputedly connected with the Stansfields of Stansfield Hall.^[3] Stansfield's entry into the profession came late. After one year of study at Owen's College, Manchester (1884–85), he transferred to the University of Edinburgh, graduating with a bachelor of medicine (MB) degree in 1889.^[4]

With an interest in pathology, Stansfield spent the last few months of his time in Edinburgh working at the Royal Infirmary. In time for his graduation in 1889, the London County Council (LCC) was established and took over the running of several London mental asylums; in the process, it advertised for a Fourth Assistant Medical Officer and Pathologist at Banstead Asylum, essentially a junior assistant with pathological duties which often related to postmortems. While there he became interested in both the pathology of mental illness and in asylum administration. Accustomed to the laboratories at Edinburgh and drilled with rigorous note-taking skills, he set about instilling similar facilities and ethos at Banstead under the auspices of its superintendent, Dr T. Claye Shaw. Each ward would also have its own fixed notebook for medical officers, a practice which over time spread to all other asylums in the country. Thanks to this and his enjoying good relations with its steward, F. Alderton, Stansfield was was made Banstead's Second Assistant Medical Officer in 1890 and, when Claybury Asylum opened in 1892–93, he was transferred there as First Assistant Medical Officer, helped by Dr Claye Shaw's influence at the LCC. Over the course of the 1890s, he visited numerous domestic and foreign institutions, travelling to Germany and the United States.^[4]

In 1898, Stansfield was appointed Superintendent at Bexley Mental Hospital and advocated the cottage or villa system of dispersed accommodation unconnected by corridors; this was, in his opinion, more economical and made classification and separation of recent cases easier. He also recommended an significant increased in the number of medical staff, and the use of parole and rewards for "practicable or industrious" patients. He was able to influence the LCC enough that they added villas to Bexley and subsequently used them at the new Hellingly Hospital (opened in 1903). Stansfield remained superintendent at Bexley until 1921 and his tenure witnessed the institution of his parole system and the construction of a hospital wing for men.^[4] The post-war years and their changes frustrated him and it was this which spurred his retirement. For the 1921–22 year, he was President of the Kent Branch of the British Medical Association.^[4]

During the First World War, Stansfield served with the Royal Army Medical Corp, eventually as a Lieutenant-Colonel, and was appointed Consultant for Nervous and Mental Diseases to the Eastern Command (1915–22); it was thanks to these services that he was appointed Commander of the Order of the British Empire in 1922.^[1] Like many other superintendents, his attitude towards war patients was less than sympathetic and he claimed that, of the 61 soldier patients admitted to Bexley, only 5 had served abroad; many others were suffering from pre-existing or general psychiatric problems (something he reiterated in a 1919 letter to The Times. In his words, a Board of Control Service Patient schem to deal with war-related psychological trauma employed "extravagent and unjust [means to] make such a distinction between soldier patients and the hundreds of patients who are far more genuinely the victims of the battle of everyday life".^[5]

Stansfield had long felt uncomfortable with the idea of medical officers marrying. Louise Hind, in Gender and Class in English Asylums, 1890–1914, hints that this might have been the result of misogynist tendencies, although is obituary-writer preemptively defended him against these claims.^[6] Stansfield nevertheless married twice; firstly, in 1908 to Mary Caroline (died 1926), a daughter of the Hon. John Dever, a Canadian senator from St John, Newfoundland. After her death, he married (in 1929) Marie, second daughter of Alexander Effremoff, of Moscow. There were no children from either marriage. He was a fond rose-gardener and it was the gardens at Southmead in Wimbledon which attracted him and his first wife. In later years he moved to Castello Devachan in San Remo, Italy, with his second wife, and it was there that he lived his last years, until moving to Paris to seek treatment for an illness; he died there on 19 February 1939.^[1][4]