Spinoza’s “Appendix” operates as a response to some misconceptions remaining about god and the cause of existence. He covers three points in the section and in the end, we get the conclusion that nature, god, has no end goal in mind and that this teleological notion -- that things have an end in view-- stems from superstition and ignorance.

I) Explaining why teleology is generally believed and adopted so naturally by men:

We begin this illustration with men, who are born in ignorance. In this ignorance they assume that all things of use to man must have a cause, and if it’s not them then it must be god, or nature. With this notion of God, something bigger than themselves, they begin vying for God's affection and appreciation by worshiping in their own special ways. It’s through their own rituals, if you will, that superstition comes about, and that burrows deeply into the human mind. Now, in setting out to explain that god, nature, is the cause of all things useful to man they run into the conclusion that god, nature, and men are all mad together. What comes of this? The idea that when it’s storming or flooding, it’s because god is angry with man for whatever reason, and man is at fault, even though they can see that good things happen to those pious and not. They believe this because it is easier to burrow deeper into superstition and ignorance than to “destroy the whole fabric of their reasoning” to start over. This was good enough to suffice men and their ignorance for an eternity, if it wasn’t for math -- and other reasons Spinoza doesn’t delve into-- that brings man to the path of truth.

II) Pointing out teleologies falsity:

Whatever is a cause is also an effect, and vice versa. It’s a cycle: being a cause, creating an effect which then has an end goal and then creates again, becoming a cause; however, god disrupts this cycle because he created all, and nothing came before except himself. This takes away the perfection of god because he didn’t have an act to act upon, and means that he created mankind in an act of desire, not as an end. Therefore, God cannot be perfect, for he has desires of things he lacks. Believers in god can’t allow for this imperfection because that which has created all things useful to man must come from perfection, so they create a new argument for their case: the reduction of ignorance argument. This is another vicious cycle, but one that sounds like a toddler who just learned how to talk: “But why?” They ask ‘why’ until you have no choice but to accept refuge in God’s Will. Why was the wind blowing? Because god. Why was that man walking there at that specific time? Because god. Enter into “The Sanctuary of Ignorance.”

They whittle away with these ‘why’ questions and anyone brave enough to try and rid themselves of the ignorance and seek true understanding is cast out as an impious heretic.

III) How teleology gave rise to prejudices and judgements:

Because man assumes everything is created for their sake, they end up associating that which is most useful to them to be the best for mankind, and further, they use this train of thought in explaining abstract notions. Thus, what leads to health and worshiping of god is called good and otherwise is bad. However, those that don’t understand the true nature of the things merely imagine them after a fashion and end up mistaking imagination for understanding. These are the individuals who believe in the idea that all things have an end in view and that god has created all things in order. So, with this confusion, they are attributing imagination to god. However, every man classifies that which affects our senses differently. What I think smells good you might think stinks. What I find pretty to the eye you might not. This goes to show that men judge things based on their mental disposition. Therefore, the idea man have that god has created everything in a perfect order is just another bit of ignorance and due to the imperfection of man’s mind.