This study deals with the philosophical approaches of thirteenth-century thinkers to concrete manifestations of 'quantum ad naturalia' in human lives and to the practical outlines and peculiarities of humanity in their commentaries on Aristotle's works on natural philosophy.

Theodor W. Köhler, Ph. D. (1969, Pontificio Ateneo S. Anselmo, Rome) is Professor emeritus of Philosophical Anthropology at Salzburg University. His publications include numerous studies on medieval philosophy including Grundlagen des philosophisch-anthropologischen Diskurses im dreizehnten Jahrhundert (Brill, 2000).