  The ethics exposed in the 9th book of De rerum natura is strictly naturalist. The only objective which Telesio ascribes to the spirit is self-preservation and self-improvement, the former lying in its ability to react suitably to influences from the external world, the latter in its capability of finding means to improve its state of being. This comes about through theoretical knowledge, specifically through natural philosophy and medicine (cf. DRN book VIII, ch. XXI) and through learning to control one's own emotions and desires. According to Telesio, we can voluntarily provoke and suppress affections and their related actions (DRN book IX, ch. I; vol. III, p. 332f.); what is more, we are able to master the degree to which we desire and are affected (DRN book IX, ch. II; vol. III, p. 334). The principle of moral virtue is said to be a knowledge of what is helpful and what is damaging for survival and well-being in human society. All virtues and vices are reduced to self-conservation.