Question about a proposition of Spinoza's Ethics

Question

In Proposition 29 of Spinoza Ethics, he says that "In nature there is nothing contingent"

My questions: What does it mean for something to be contingent? and what follows from the claim that nothing is contingent?

Answer 1

The word “contingent” in broader usage means subject to chance or depending on the way things are.

However, philosophers use the word “contingent” and “necessary” specifically to describe ways of being or existing (for both things and properties). Something exists contingently if and only if it does not exist necessarily. Something exists necessarily if and only if it must exist—if it cannot fail to exist. Something necessarily has a property if and only if it must have that property and cannot fail to. So, in contrast, something exists contingently if and only if it can fail to exist, under some circumstances. Philosophers say of such things that they are contingent. The term implies that the things existing or failing to exist depends on other things, on circumstances, or the like.

If nothing is contingent, then everything is necessary, meaning that everything that exists must necessarily exist and could not have failed to exist. This is equivalent to the thesis called “determinism.” (In turn the thesis of determinism is often thought to have the implication that actual free choices are impossible—that there is, that is to say, no free will.) If you are interested in learning more about Determinism, you might try the SEP article on causal determinism.