The phrase "per se" is a Latin phrase meaning "of, in, or by itself". The "se" part is what contributes the "itself" to that.
Atheist writers note well: It is not "per say".
If you're going to use it like that, you'll sound like a moron, or even worse, a fundie.
per freaking se
Don't even get me started on "voilà". Voila is okay, since English doesn't do graves and accents and cedillas and umlauts and such but so often incorrectly written viola, or walla or wallah. If I get going on that one, I am liable to insert a "viola" in someone's nose.