implicit - implied values
explicit - values made apparent more bluntly, ie "throwing them in the readers face"
eg. lets take religion as an example
if a character were to state "God, whose wretched creations upon this earth inhabit" it could be considered as implicitly saying "Religion is bad"
on the other hand,
if a character were to say "I don't like the values of religion", it could be regarded as explicitly expressing the characters views on religion
the examples arent that great but you get the jist of it