james young simpson (born june 7, 1811 in scotland) was a qualified doctor by the age of 21 but changed to work as a clerk, due to his traumatic reaction to witnessing mastectomies during his medical training. he sat in several lecture courses as a student, but the anatomical lecture by a doctor knox made him choose the career path of midwifery and obstetrics. he became a qualified professor of midwifery at the age of 29, in 1840.