Plurality is not to be posited without necessity.

Entities must not be multiplied beyond necessity.

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

When you have two competing theories that make exactly the same predictions, the simpler one is the better.

For nothing ought to be posited without a reason given, unless it is self-evident (literally, known through itself) or known by experience or proved by the authority of Sacred Scripture.

What can be explained by the assumption of fewer things is vainly explained by the assumption of more things.

Entities are not to be multiplied beyond necessity.