Josef Pieper (German: [ˈpiːpɐ]; May 4, 1904 – November 6, 1997) was a German Catholic philosopher, at the forefront of the Neo-Thomistic wave in twentieth century Catholic philosophy. Among his most notable works are The Four Cardinal Virtues: Prudence, Justice, Fortitude, Temperance; Leisure: the Basis of Culture; The Philosophical Act and Guide to Thomas Aquinas (published in England as Introduction to Thomas Aquinas).