Arthur was educated at Clongowes, and at the Catholic University, Dublin, qualifying M.B., BCh., B.A.O., R.U.I. He received a commission in the medical services at the rank of Lieutenant on 31st July 1905, then served in Malta from 1907 to 1908 and in India from 1908 to 1912. During this time he gained promotion to Captain on 1st March 1909. In 1913, Arthur became a specialist in physical training. When war was declared he was stationed in Aldershot. He entered the war in France on 13th August 1914 as the Medical Officer of the 2nd Bn. Royal Munster Fusiliers but became a prisoner of war until 1915, when he was repatriated back to the UK. In 1915, Arthur was posted to serve in Salonika and remained there until 1918. During this time he was promoted to temporary Major on 16 August 1916, but served under the rank of acting Lieutenant Colonel from 22nd August 1916 to 8th June 1918. He received the full rank of Major on 31st July 1917. From 1920 to 1924 he was posted to India, and from 1929 - 1930 he was posted to China. On the 30th July 1930 he was promoted to Lieutenant Colonel, then retired on pay. He ceased to be on the Roll of Officers on 2nd November 1932.