  Already in Temporis Partus Masculus (1603) Bacon had displayed a “facility of shrewd observation” (Sessions 1999, 60) concerning his ideas on induction. In his Novum Organum the nature of all human science and knowledge was seen by him as proceeding most safely by negation and exclusion, as opposed to affirmation and inclusion. Even in his early tracts it was clear to Bacon that he had to seek a method of discovering the right forms, the most well known of which was heat (Novum Organum II, Aph. XI–XII) or “the famous trial investigation of the form of heat” (Rees 2000, 66; see Bacon IV [1901], 154–5).