  These spirits are never at rest. In the Novum Organum, then, Bacon  rejected the “existence of eternal and immutable atoms and the reality of the void” (Kargon 1966, 47). His new conception of matter was therefore “close to that of the chemists” in the sense of Bacon's semi-Paracelsian cosmology (Rees 2000, 65–69). The careful natural philosopher tries to disclose the secrets of nature step by step; and therefore  he says of his method:  “I propose to establish progressive stages of certainty” (Bacon IV [1901], 40: Novum Organum, Preface). This points towards his inductive procedure and his method of tables, which is a complicated mode of induction by exclusion. It is necessary because nature hides her secrets. In Aphorism XIX of Book I in his Novum Organum Bacon writes: