_ Source: _Volume 62, Issue 1, pp 69 - 89 Galen’s physiology—his theory of elements, mixtures and the emergence of natural capacities—compels him to conceive of each part of the soul as a peculiar mixture of elementary qualities in the material substance of the organ in which it is located. The reason why Galen, nevertheless, refrains from making a dogmatic assertion about the substance of the soul, or of human nature in general, is the acknowledged failure to account for two (...) goal-directed activities—the formation of bodily organs and human intelligence—in terms of elementary qualities and their mixtures. (shrink)