This is a translation of Frauwallner's Abhidharmastudien. It analyzes the literary traditions, doctrinal tendencies, and structural methods of the Buddhist Abhidarma canon in order to expose the beginnings of systematic philosophical thought in Buddhism. Frauwallner's insights illuminate the path of meditation toward liberation, the development of Buddhist psychology, and the evolution of the Buddhist view of causality and the problem of time. He provides a clear explanation of the gradual development of Buddhist thought from its early doctrinal beginning to some of the most complex and remarkable philosophical edifices in history.