
...and I avoid contact with other people
on general PRINCIPLE.
The Big Bang Theory Season 3, Episode 15

of Heisenberg's
uncertainty PRINCIPLE,
The Big Bang Theory Season 5, Episode 5

That's sort of like
the uncertainly PRINCIPLE.
The Big Bang Theory Season 4, Episode 20

In PRINCIPLE, you have a point.
The Big Bang Theory Season 1, Episode 15

should avoid espousing
the PRINCIPLE
The Big Bang Theory Season 7, Episode 22