 This is easily confirmed by looking briefly at some of their main convictions concerning knowledge, starting with Thomas Hobbes (1588–1679). As Hobbes points out in the chapters Of Philosophy and Of Method in the first part (Computation or Logic) of the first section (Concerning Body) of his Elements of Philosophy (1655), knowledge is the result of the manipulation of sensory input based on the employment of logical rules of reasoning (ratiocination) in acts of what he calls “computation”. He describes the details of this process most succinctly in a short passage in chapter 6 of the first part (Human Nature) of his The Elements of Law, Natural and Politic (1640), his first major philosophical work. After distinguishing what he calls “sense, or knowledge original” from “knowledge … which we call science”, he goes on to “define” knowledge “to be evidence of truth, from some beginning or principle of sense” and formulates four principles that are constitutive of knowledge: