Editing New riddle of induction (section)

==== Habit formation ====
Induction itself is essentially [[Classical conditioning|animal expectation]] or habit formation. [[Ostensive definition|Ostensive learning]]{{sfn|Quine|1974|loc=Sect. 11}} is a case of induction, and a curiously comfortable one, since each man's spacing of qualities and kind is enough like his neighbor's.{{sfn|Quine|1970|p=47}} In contrast, the "brute irrationality of our sense of similarity" offers little reason to expect it being somehow in tune with the unanimated nature, which we never made.{{efn|Quine seems to allude to Vico's [[Giambattista Vico#The verum factum principle|verum factum principle]] here.}} Why inductively obtained theories about it should be trusted is the perennial philosophical [[problem of induction]].  Quine, following [[Satosi Watanabe|Watanabe]],{{sfn|Watanabe|1965|p=41}} suggests [[Charles Darwin|Darwin]]'s theory as an explanation: if people's innate spacing of qualities is a gene-linked trait, then the spacing that has made for the most successful inductions will have tended to predominate through [[natural selection]].{{sfn|Quine|1970|p=48}} However, this cannot account for the human ability to dynamically refine one's spacing of qualities in the course of getting acquainted with a new area.{{efn|Demonstrated by psychological experiments e.g. about classification of previously unseen artificial objects, like "[[Greeble (psychology)|Greebles]]".}}