The quote below is from Spinoza’s Ethics, Part 4. For those unfamiliar with the term, “final cause” refers to the purpose for which something is done – the end goal. Spinoza is saying quite clearly here that Nature, or God, has no final cause. There is no purpose to be found in existence other than existence itself. All Spinoza is difficult, and the quote below is one of the easier passages!
“He who has undertaken something and has brought it to completion will say that the thing is completed; and not only he but everyone who rightly knew, or thought he knew, the intention and aim of the author of that work. For example, if anyone sees a work (which I assume is not yet finished) and knows that the aim of the author is to build a house, he will say that the house is imperfect. On the other hand, as soon as he sees that the work has been brought to the conclusion that its author had intended to give it, he will say that it is perfect. But if anyone sees a work whose like he had never seen before, and he does not know the artificer’s intention, he cannot possibly know whether the work is perfect or imperfect.
This appears to have been the original meaning of these terms. But when men began to form general ideas and to devise ideal types of houses, buildings, towers, and so on, and to prefer some models to others, it came about that each called “perfect” what he saw to be in agreement with the general idea he had formed of the said thing, and “imperfect” that which he saw at variance with his own preconceived ideal, although in the artificer’s opinion it had been fully completed. There seems to be no other reason why even natural phenomena (those not made by human hand) should commonly be called perfect or imperfect. For men are wont to form general ideas both of natural phenomena and of artifacts, and these ideas they regard as models, and they believe that Nature (which they consider does nothing without an end in view) looks to these ideas and holds them before herself as models. So when they see something occurring in Nature at variance with their preconceived ideal of the thing in question, they believe that Nature has then failed or blundered and has left that thing imperfect. So we see that men are in the habit of calling natural phenomena perfect or imperfect from their own preconceptions rather than from true knowledge. For we have demonstrated that Nature does not act with an end in view; that the eternal and infinite being, whom we call God, or Nature, acts by the same necessity whereby it exists. So the reason or cause why God, or nature, acts, and the reason or cause why he exists, are one and the same. Therefore, just as he does not exist for an end, so he does not act for an end; just as there is no beginning or end to his existing, so there is no beginning or end to his acting. What is termed a “final cause” is nothing but human appetite insofar as it is considered as the starting point or primary cause of some thing.”
Spinoza – The Ethics Part 4 Preface