All 3 Uses

contrary
in
The Voyage of the Dawn Trader
(Edited)

"Secondly," said Caspian, "I want to know why you have permitted this abominable and unnatural traffic in slaves to grow up here, contrary to the ancient custom and usage of our dominions."
Chpt 4

contrary to = in opposition to
And the service they ask of her is in no way contrary to her Majesty's honour, but a noble and heroical act.
Chpt 9 *
On the contrary he liked him very much and was therefore frightened about him, and being frightened put him in a bad temper — just as your mother is much angrier with you for running out into the road in front of a car than a stranger would be.
Chpt 15 *

on the contrary = an expression used to intensify denial of an idea

Definitions:

(1) (contrary as in: a contrary idea)
different (perhaps opposite or mutually exclusive)

In formal logic, contrary propositions or contrary arguments describe two things that cannot both be true. They might be described as mutually exclusive. For example, a pet cannot be both a cat and a dog. It doesn't need to be either, but if it is one, it cannot be the other. So the statement that a pet is a cat and the statement that the same pet is a dog, are contrary statements.
(2) (contrary as in: a contrary personality)
disagreeable -- typically in reference to someone's personality
(3) (contrary to as in: contrary to)
in opposition to

You could also think of this as meaning, despite, or in spite of, or in conflict with; but since a common meaning of contrary is opposite, you many find it easiest to think of contrary to as in opposition to.
(4) (on the contrary as in: on the contrary)
an expression used to intensify denial of an idea
(5) (to the contrary as in: to the contrary)
with an opposite or different effect; or something with an opposite or different effect
(6) (meaning too rare to warrant focus)