Pluralitas non est ponenda sine necessitate. A plurality (of reasons) should not be posited without necessity.

It is vain to do with more what can be done with less.

Of two equivalent theories or explanations, all other things being equal, the simpler one is to be preferred.

3 is a prime, 5 is a prime, and 7 is a prime. Why bother with non-prime numbers when the primes can do everything?

Simpler explanations are, other things being equal, generally better than more complex ones.

Intuitive cognition of a thing is cognition that enables us to know whether the thing exists or does not exist, in such a way that, if the thing exists, then the intellect immediately judges that it exists and evidently knows that it exists, unless the judgment happens to be impeded through the imperfection of this cognition.

God's existence cannot be deduced by reason alone.