Usually, if we hate, it is the shadow of the person that we hate, rather than the substance. We may hate a person because he reminds us of someone we feared and disliked when younger; or because we see in him some gross caricature of what we find repugnant in ourself; or because he symbolizes an attitude that seems to threaten us.
"Hate Is Rarely a Personal Matter" - The Best of Sydney J. Harris (1975)