Complex sentence: He was introduced to anthroposophy through his classmate, Walter Johannes Stein (1891-1957), and in 1914 first attended lectures given by Rudolf Steiner, the founder of anthroposophy.
Split into simpler sentences: He was introduced to anthroposophy through his classmate, Walter Johannes Stein (1891-1957). In 1914 he initially attended lectures given by Rudolf Steiner, the founder of anthroposophy.