It was necessary that the very noble form of man, which is the image and likeness of God... should be joined to the substance of dust and darkness, the source of all defect and loss. For these reasons the Creator gave to the form of man power, rule, and dominion over the substance;—the form can subdue the substance, refuse the fulfillment of its desires, and reduce them, as far as possible, to a just and proper measure.

Ch.8 - Guide for the Perplexed (c. 1190) - Part III