Johannes Jacobus (Johan) Degenaar (7 March 1926 - 22 July 2015) is a South African philosopher, and Emertitus Professor at the Stellenbosch University, who is considered "one of the most respected and influential philosophers in South Africa."
Degenaar started to study theology and philosophy in 1943 at the University of Stellenbosch, where he obtained his MA degree in 1948 with a thesis entitled Kennis as Lewe (Life of knowledge), advised by Professor Freddie Kirsten. He continued to study Dutch, and graduated with a doctoral dissertation on Max Scheler's ethics advised by Helmuth Plessner. In 1951 he obtained his PhD under the supervision of Kirsten Bosch for the thesis entitled "Die herhaling van die vraag na die filosofie" (Repeating the question of philosophy). In 1949 he started as lecturer in philosophy at the University of Stellenbosch. In 1969 he was appointed as Professor and later also as Head of Department. Among his PhD students was Paul Cilliers (PhD, 1994). These roles he fulfilled until his retirement in 1991.
In 1984 he was awarded the Stalsprys; in 1998 the NP van Wyk Louw medal; and in 2004 the Order of Ikhamanga for his "excellent contribution to philosophy and literature, his intellectual honesty and principled role in the broad struggle to resist conformity to the apartheid ideology." The University of Port Elizabeth (1997) and the University of Stellenbosch (2001) granted him honorary doctorates. He is married to Jetty Maria, born Houtman, and has two sons, Hans and Marc. They live in Stellenbosch.
In the 1950s Degenaar was primarily concerned with phenomenological-existential, aesthetic and theological work in philosophy. He lectures on the works of Søren Kierkegaard, and through his courses and writings of Albert Camus and Martin Heidegger he introduced South Africans to existentialism. His motto in life and work was the Socratic statement "'n Ongeëksamineerde lewe is nie die moeite werd om te leef nie" (An unexamined life is not worth living).