the child is father of the man
The personality traits that one displays as an adult form in childhood. He's always been a quiet, analytical person—the child is father of the man, after all.
child is father of the man
and child is father to the manProv. People's personalities form when they are children; A person will have the same qualities as an adult that he or she had as a child. (From William Wordsworth's poem, "My Heart Leaps Up.") In Bill's case, the child was father of the man; he never lost his childhood delight in observing nature.