Principle of Sufficient Reason

The Principle of Sufficient Reason (PSR) is the assertion that everything has an explanation and that nothing can exist or happen without reason or cause.

The PSR exists because it's logically impossible for it not to exist. Without the PSR, there would be no reason for anything to happen at all.

The PSR is nothing, needs nothing and nothing can stop it. Ontologically, the PSR exists as collections of flowing points, i.e. as monads. 

The Anti-PSR

The opposite of the PSR, the "anti-PSR", where things happen for no reason at all is impossible. Nothing would happen in the first place because there would be no reason for anything to happen.

Randomness itself cannot exist ontologically because there would be nothing to start the randomness and nothing to determine the outcome.

100% PSR

The universe cannot be 60% based on reasons and 40% based on nonreasons. This introduces an impossible dualism, how would reasons and nonreasons interact? Either the universe is 100% based on the Principle of Sufficient Reason or it is based on things happening for no reason at all, which is a universe that would never be able to start in the first place as it would have no reason to.

Self-evidently, we exist and events happen. Therefore, everything has a reason.

Perfection

The PSR is perfect. It cannot contain a single error or it would collapse instantly under the weight of its contradictions.

Occam's Razor

There is no reason for existence to do anything more complex than necessary, it would have no reason to do so. Amongst competing explanations, the one that requires the fewest assumptions is always correct.

Principle of Insufficient Reason

When there are multiple possible outcomes and no reason to choose one over another, then we have a reason to treat them as all being equally probable.