In 2002, he was one of the five judges who heard the appeal of Abdelbaset al-Megrahi against his conviction for the bombing in 1998 of Pan Am Flight 103.
He was educated at Hutchesons' Boys Grammar School and then at Glasgow University, where he won many prizes and graduated in law in 1967.
His ashes are buried in Dean Cemetery in western Edinburgh, slightly north of the main entrance, facing the eastern path.
In 1994 Macfadyen one of the first people to be appointed a temporary judge of the Court of Session.
In 1995 his promotion was made permanent, when he was appointed as a Senator of the College of Justice.