Born in Broughton-in-Furness in Cumbria, Philipson was educated in Whitehaven and Dumfries. He enrolled at the Edinburgh College of Art in 1936, where his teachers were David Alison, John Maxwell and William Gillies. Following graduation he served in the army in India and Burma. After demobilisation he joined the staff of ECA in 1947 and remained there for 35 years, the last 22 years as Head of the School of Drawing and Painting balancing the roles of teacher, administrator and painter.
William Gillies was an early influence, but it was a study of the technique of Kokoschka through which Philipson laid the basis for his mature style.
In the course of his career as a painter he executed a series of thematic paintings, starting with his Cockfights and including Rose Windows, Men observed and Poppies. Although he was mainly a figurative painter, some of his work was an abstract exaltation of the qualities of paint. In all his work he delighted in manipulating rich, sensuous colour.
He was the President of the RSA between 1973 and 1983.