Arthur was educated at the Bolton High School for Boys; at Epworth College, Rhyl; and at Edinburgh University - where he graduated M.B., Ch.B. in 1907. He then went to Berlin to study ear, nose and throat work, and from there was appointed house-surgeon to the Birmingham Ear, Nose and Throat Hospital. He then went to the King Edward VII Hospital in Cardiff, where he acted as house-surgeon to the ear, nose and throat department for two years, and as house-surgeon in the surgical wards for 6 months. He continued practice in Cardiff as an ear, nose and throat specialist, and was appointed by the corporation to attend ear, nose and throat cases notified for treatment by the school medical officer. He became secretary of the Cardiff Division of the British Medical Association, which post he had to relinquish on accepting a commission in the R.A.M.C. He took a significant role in getting a large number of medical men to accept commissions in the army. He died after a prolonged illness. He was the son of Dr and Mrs Thornley of Bolton.