What is perhaps most striking about "De rerum natura" is Telesio's attempt to mechanize as much as possible. Telesio clearly strives to explain everything in terms of matter informed by hot and cold and to keep his arguments as simple as possible. When his discussions turn to human beings he introduces an instinct of self-preservation to account for their motivations. And when he discusses the human mind and its ability to reason in the abstract about immaterial and divine topics, he adds a soul. For without a soul, all thought, by his reasoning, would be limited to material things. This would make God unthinkable and clearly this was not the case, for observation proves that people think about God.