This guide is intended to help you find your way through the "Appendix to Book I" of Spinoza's masterpiece, The Ethics, in which Spinoza attacks final causes. You should begin by reading the Appendix, and then, on the second reading, go back and forth between this guide and the various sections of the Appendix which it points you to. This will help you to pick out the parts of Spinoza's discourse, and to see what is important about them. There are some exercises along the way which may also help you to understand this difficult reading.
First of all, what is a final cause? One answer is that a final cause is one of Aristotle's fours causes - material, formal, efficient and final. To understand these different kinds of cause, consider a statue. The material - say bronze - of which the statue is made is its material cause. The form of the statue - say Venus - is its formal cause. The efficient cause is the sculptor who makes the statue, and the final cause is the purpose for which he makes the statue - e.g. to amuse the Pope. One might attribute final causes to things, e.g. my heart is beating more rapidly in order to increase circulation; or people, e.g. she is exercising for her health; or on a more cosmic level to God, e.g. He made the seas for fish to live in.
Part of the revolt against Aristotle in the 17th century, involves reducing these four causes, including final causes, to one - efficient causality. Spinoza is part of that revolt. And yet, there is another strand of thought in the 17th and 18th centuries which makes much out of final causes, and is at the heart of the new mechanical philosophy. The teleological argument for the existence of God is an argument which combines final causes with the mechanical philosophy. It says that the world is like a vast machine. Every machine has a maker, the world is a machine, so the world too must have a maker. Every machine is made for a purpose, and the purpose of the world machine is to satisfy the needs of man, the most important creature on the earth. Spinoza clearly intensely dislikes final causes, and since he rejects the notion of a creator God, he has no use for the teleological argument. Part of the Appendix to Book I of the Ethics is an attack on the notion of final causes on which the teleological argument depends.
Spinoza begins by noting that he has stated various truths about God in Book I of the Ethics and that it is his aim to remove various prejudices which prevent people from seeing these truths. All of these prejudices depend on a belief in final causes!
So, Spinoza is going to show 1. Why most people are satisfied that it is true that there are final causes and why nature compels us to embrace this doctrine. 2. That the doctrine of final causes is false. And 3. How from belief in this doctrine prejudices have arisen regarding good and evil, merit and sin, praise and blame, order and confusion, beauty and ugliness and other things of this kind! Surely, we must wonder what is the connection between the doctrine of final causes, and such a set of remarkable terms.
Now let's make a guess: How are we going to get from a belief in final causes to views about good and evil, merit and sin, praise and blame. One possibility is this: Spinoza thinks there is a connection between final causes and free will. Free will has all kinds of connections with good and evil and merit and sin. If you believe in free will then you hold that one can be held responsible for acts, good or bad, which are freely done, and so rightly praised or blamed, punished or rewarded. But Spinoza does not believe in free will -- so it may be that all the consequences which follow from a belief in free will he regards as prejudices. Still, this guess or hypothesis does not explain the connection between final causes and order and confusion, beauty and ugliness very well. Nor does it tell us what the connection between free will and final causes is. So, we want to see if there is a connection between free will and final causes, and we may expect that there is something else going on in addition which will explain the other pairs of terms.
The first paragraph of the section I. (on Pg. 110) nicely confirms our guess. First, Spinoza says, men are born in ignorance of the causes of things and (here comes the something else in addition) they all want to seek their own advantage, and are conscious of this appetite. Spinoza may have got this idea from reading Hobbes. From these two assumptions about our nature if follows that:
Furthermore, they find, both in themselves and outside themselves-- many means that are very helpful in seeking their own advantage, for example, eyes for seeing, teeth for chewing, plants and animals for food, the sun for light, the sea for supporting fish...Hence they consider all natural things as means to their advantage. So, looking at the universe as the means to my end (my own advantage) I come to hold that the universe must have been made for that purpose. And if it was made for that purpose, it did not make itself but rather was made by a ruler of Nature, endowed with human freedom, who had taken care of all things for men, and makes all things for their use.
This is a classic statement of the teleological argument (in Greek telos means end). Furthermore Spinoza claims that "they infer the temperament or character of the gods from their own. He continues (top of Pg. 111):
Hence they hold that the gods made all things for man in order to bind men to them and be held in the highest honor. So each tried different ways to get God to love him above the rest, and to direct the whole of nature according to their blind desire and insatiable greed. Thus this prejudice was turned into superstition.
The discussion now continues about how people who are captured by this superstition deal with counter-instances to the claim that Nature does everything for man. In effect, Spinoza turns to the problem of evil. If Nature is made for us then why are there are so many inconveniences, "...storms, earthquakes, diseases and the like."? Spinoza continues (middle of Pg. 111):
These, they maintain, happen because the gods are angry with them on account of the wrongs done to them by men...And though their daily experience contradicted this, and though infinitely many examples show that conveniences and inconveniences happen indiscriminately to the pious and the impious alike, they do not give up their long-standing prejudice.
Why? Too much work to think of another scheme! "So, they maintained it as certain that the judgment of the gods far surpasses man's grasp." Spinoza remarks that this alone would have kept the truth hidden from human beings for eternity were it not that mathematics showed men another standard of truth, which has nothing to do with final causes.
We now come to section II. (bottom of Pg. 111) So Spinoza has explained why men are inclined to believe that all things act for an end. He is now going to show that Nature has no end set before it and that "final causes are nothing but human fictions." Spinoza claims he has already established this by showing the origin of the prejudice, and that in the body of Book I he has established that "all things proceed by a certain eternal necessity of Nature, and with the greatest perfection" Spinoza goes on to argue that the doctrine of final causes takes away God's perfection -- for if God acts for the sake of some end, then he necessarily wants something that he lacks, and to say that God lacks something is to say that It is not perfect. Another point Spinoza makes is that those who assign ends to all things reduce all things to ignorance - because if we trace the causes of any given event back, we end with the will of God, "that is the sanctity of ignorance." This is so because if God has free will like humans, once we trace the chain of causes back to God's will, there will be no reason or explanation of why one thing was chosen rather than another. (This is the point of the example of the man who dies from a stone falling off the roof as he walks by.) Spinoza remarks (top of Pg. 113) that similarly "...when they see the structure of the human body, they are struck by foolish wonder, and because they do not know the causes of so great an art, they infer that it is constructed, not by mechanical, by divine, or supernatural art..." (The wonders of the construction of the human body are often used to motivate the teleological argument.) So, anyone who tries to investigate causes in nature as any intelligent educated person should, and seeks to understand and not wonder at them "is generally considered an impious heretic and denounced by those who the people honor as interpreters of Nature and the gods."
In the third section we come to Spinoza's explanation of those remarkable pairs of terms, good and evil and so forth. The basic point about good and evil, is that people take things which are in their interest as good and those which are not as evil. Thus they define good as whatever conduces to health and worship of God. He says (Pg. 113) that those whose condition he has analyzed "do not understand the nature of things, but only imagine them, affirm nothing concerning things, and take the imagination for the intellect..." So, here we have the Cartesian distinction between sense, imagination and intellect used to explain the errors of those who have not reached true understanding! Spinoza continues with the other examples he proposes to explain (those which do not depend on free will which he proposes to treat later) -- and the explanation for all the rest is roughly the same. In each case, people take what is of advantage to them as the standard (See Pg. 114 first paragraph for a clear summary of this point). Thus, Spinoza says (bottom of Pg. 113) that things "which we can easily imagine are especially pleasing to us, men prefer order to confusion, as if order were anything in Nature more than a relation to our imagination."
What is really interesting about this discussion is the treatment of relativity of views and the skepticism it engenders. Spinoza treats this as simply yet another case of mistaking the imagination for the understanding! (See the three paragraphs on Pp. 114-5 which start "All of those things show sufficiently...")