Ruin was the son of Professor Waldemar Ruin and Flora Henrika Lindholm. He married Karin "Kaisi" Sievers (1894) in 1917, daughter of physician and
Freifrau Karin von Bonsdorff. He had two children, Martina and Olof, and is maternal grandfather to
David and
Marika Lagercrantz. His grandchild was also named and became a philosopher. Ruin graduated from in 1909. He received his Candidate of Philosophy degree from the
University of Helsinki in 1913, followed by his Licentiate in 1921 and Doctor of Philosophy in 1923. His academic dissertation was titled
Erlebnis und Wissen. In his dissertation, Ruin was critical of behaviourism, viewing humans as intellectual beings, a conviction he never abandoned. Ruin was a varied writer, who authored works on topics ranging from continental philosophy to art and literature, as well as autobiographical pieces.
Analytical philosophy, an increasingly dominating subject within philosophy at the time, felt foreign to him however. This was one of the reasons why he left Finland and moved to Sweden to pursue the study of
aesthetics. Subsequently he obtained Swedish citizenship. His time in Sweden began as a Nordic docent fellow at
Stockholm University College (1944–1945) and
Lund University (1945–1947). He subsequently became a docent of aesthetics at Lund University from 1947 to 1952, and was a research docent there from 1952 to 1957. Ruin was also active in several cultural organizations. He was a contributor to the journal from 1920 to 1946, chairman of the from 1930 to 1931, a board member of the (1934–1945), serving as its chairman in 1936 and again from 1944 to 1945. He also served on the board of the
Society of Swedish Literature in Finland from 1934 to 1946. In Sweden, Ruin became one of the most popular public cultural speakers, admired especially in student circles. During 1952–1957 he served as inspector of
Malmö nation at
Lund University. His essays became increasingly free in form, which, while perhaps academically less valued, was central to his role as an opinion-forming cultural critic with an exceptional ability to articulate aesthetic experience to broad audiences.
Svenska kulturfonden sponsored an award in 2003 called the Hans Ruin essay contest for essay writers. The contest is arranged every three years. == Awards ==