What's the meaning when we say "per se"? [closed]
Solution 1:
It's supposed to show that the preceding part should be considered on its own merits without anything external, but it's often used to just emphasise that the preceding part is (not) really enough to explain the proceeding part or, as in your example, used as a high brow version of not really.
In your example, 1 and 3 are interchangeable. by definition is used in the opposite scenario.
per se is usually used in a negative construction, whereas by definition is usually used in positive constructions.