Despite his lack of worldly success Koechlin was apparently a loved and venerated figure in French music, his long flowing beard contributing to his patriarchal image. Following his 1888 illness the need to build up his strength led him to become an enthusiastic mountaineer, swimmer and tennis player. He was also an amateur astronomer and an accomplished photographer. He was one of the great nature-mystics among French composers, whose personal creed was pantheistic rather than Christian.