Chapter 119 - The Production of Man's Body

Man's true nature includes the substance derived from nutriment, inasmuch as it is identified with flesh and bone; and we must reject the opinion that man's true nature has only to do with the matter created at the beginning in the first man and derived from him to all others. Nutriment is a kind of stimulus to resist loss, as alloy is to the precious metals. Multiplication of bodies is therefore made by nutriment, which becomes part of human nature, as we see in the case of animals and plants. The opinion is to be rejected which teaches that the matter which is at first received by the soul belongs to human nature, and that because this was not sufficient other matter was added through the change of nutriment into the substance nourished to make up the necessary quantity, and hence that such matter belongs to human nature only secondarily. This opinion cannot stand; because if the nutriment were not changed into the substance, generation would not take place according to individual likeness. Nutriment is not meant only for increase, but to restore, and thus it makes up for loss, and belongs to the one individual nature, as what is lost belonged to it also.