Notes on PSR

1) Even if the principle of sufficient reason (PSR) is not subject to direct demonstration, it can nevertheless be shown to be true by appeal to various forms of reductio ad absurdum:

• Denial of the PSR is unscientific, and leads to skepticism regarding our ability to know the world. Science could not proceed without admitting that our direct observations reveal an order of efficient causality to which the world is subject; more specifically, the PSR is ubiquitous in the practice of inductive reasoning, whereby we infer the principle from particular causal instances.
• If we renounce the PSR — and what reasons do we have for doing so, other than to avoid the conclusions of cosmological arguments? — then we will have effectively undercut our ability to account for the regularities of nature. For any physical state of affairs P, it would be permissible to say: P came to be from nothing, that is, uncaused. And if, after all, the universe can come to be without a cause, then less grand suppositions are surely feasible.
• If it is possible for something to come to be out of nothing, then why do we not see things spontaneously coming into being all the time? Absent some conditional or limiting factor — something which conditions or limits Nothing from sometimes producing Something, sometimes not — we would have no reason to assume that this could not happen. And, given that there is no intermediary between Being and Non-Being, it is hard to see what such a factor would consist of. But then the converse would seem to be true also. If things can come into being from nothing, then surely they can also instantly return to nothing. For what has the power to create should have an equal power to destroy. So, why do we not find existing things blipping away into nothing?

2) To say of something that exists that it is uncaused just is to say that it has its reason of being within itself; it exists of its own nature. Now, what exists of its own nature cannot fail to exist. But the universe, according to modern cosmology, came to be; hence, it does not possess within itself its reason of being.

3) Does the Heisenberg uncertainty principle give us reasons to doubt the principle that ex nihilo nihil fit? It does not. For although the principle admits the possibility of the spontaneous arising of virtual particles out of the quantum vacuum, this vacuum bears no resemblance to the void of Newton: the quantum vacuum is a landscape of energy and particles in constant interaction; it is very much something concrete. So, whatever the full causal account of these virtual particles, their coming to be is not ex nihilo.

4) If God existed to cause himself, then he would not need to cause himself, since he would already exist. And if he did not exist, then he would not be anything such as to be able to cause himself. Either scenario is, of course, absurd. Hence, we have good reason to deny the concept of causa sui, not just with respect to God, but with respect to anything at all. For what is it about things in the natural order which renders their self-causation coherent in a way that it isn’t for God?

5) Take the PSR to be the claim that reality is intelligible, together with the claim that the concept of magic denotes any power or cause that is intrinsically unintelligible. We may offer the following argument:

S1. If PSR is false, then magic is real.
S2. But magic is not real.
S3. So, PSR is true.

This post is dedicated to Margaret Peters.