Stage 1 — Infancy (birth to two years).
We are born capable of sensation and from
birth are affected in diverse ways by the objects around us. As soon as
we become conscious of our sensations, we are inclined to seek or avoid
the objects which produce them . . . These inclinations (to seek
or avoid) extend and strength the growth of sensibility and intelligence,
but under the pressure of habit they are changed to some extent with our
opinions. The inclinations before this change are what I call our nature.
In my view everything ought to be in conformity with these original inclinations.
(Emile, Book 1, 1956)