God's existence cannot be deduced by reason alone.

Entities are not to be multiplied beyond necessity.

Never increase, beyond what is necessary, the number of entities required to explain anything.

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

Plurality should not be assumed without necessity.

Entities must not be multiplied beyond necessity.

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