Spinoza's Ethics: III.P4

Nulla res nisi a causa externa potest destrui.

There is no thing able to be destroyed unless it is by an external cause.

DEMONSTRATIO: Hæc propositio per se patet; definitio enim cujuscunque rei ipsius rei essentiam affirmat sed non negat sive rei essentiam ponit sed non tollit. Dum itaque ad rem ipsam tantum, non autem ad causas externas attendimus, nihil in eadem poterimus invenire quod ipsam possit destruere. Q.E.D.

This proposition is evident through itself: for the definition of whatsoever thing itself affirms the essence of the thing but it does not deny or it places the essence but does not remove it. Thus as long as we attend so to the thing itself, moreover not to external causes, we are able to find nothing in the same which is able to destroy itself. 

In this proposition, Spinoza describes a tendency of a thing to persist - only externals remove or alter a thing. This inherent quality of things to persist provides a key part of the fabric of the material world. A thing whose essence is not to persist would be self-contradictory and form an unstable system. This certainly seems true at the visible scale of our world. However, it does seem like some sub-atomic dynamics contradict this proposition.