A very simple argument in favor of Ethics.

This would apply to athiests as well as those who believe in a God.

I was reading Descartes and he stated that a man should be able to use his sound judgment to deduce ethics on his own, even without the help of ancient writings and great minds.

I do not have a great mind, but I started thinking about it myself, and came up with a decent reason as to why everyone should be ethical.

All people enjoy the acquisition of knowledge. People also enjoy pleasure. Some people value one more than the other.

A person who seeks mostly pleasure may find ethics to be less valuable than a person who seeks truth. However, a person who lives without ethics will continually be looking over his shoulder. Even the most clever deceiver will have to allocate some of his time to keep himself from getting caught or from having vengeance exacted upon him.

What is a better life? A life of peace and contentedness? or a life where one is constantly having to fear the indignation he will receive from others?

I realize that a student of ethics will find the ideal in this: a person who does the right thing because they WANT TO. But even if a person does so in a begrudging manner, his life would be more peaceful than say, a mafia mobster. Is a short life full of pleasure better than a life of peace and knowledge?

Descartes presupposes that “good sense” is what is needed to deduce a sound ethics of ONES own. You go onto your reason of how EVERYONE should be ethical. I think it is in Part 4 of his Discourse, he states that one should not try to change the world, but him. How do you know that you’re “learned” way of being ethical is the same as others perceive the word “ethical” to be?
“Even the cleverest deceiver will have to allocate some of his time to keep himself from getting caught or from having vengeance exacted upon him.” But what if this person gained a certain pleasure from living life a different way to yours- thus being their “learned” ethic of living.
However this is where another entanglement lies:
Descartes proposed “I think therefore I am” Thus referring to the “I”. However is it possible to have an ethical explanation of ones own, if you are using a “language” to explain it, referring back to Wittgenstein’s language games? If so then it is not possible to conjure an ethic of ones own.

a preacher was asked the need for religion by this woman. While she was saying her reasons for not likeing the rules of religion, the preacher started looking though her purse. Then the lady yell, “What’s wrong with you!!!”

I don’t. However, you stated that a person may begin to enjoy “constantly looking over his shoulder.”

Let’s take it that way then. Assuming there is no all-encompassing set of “correct” ethics, we would be purely biological beings. Nothing metaphysical. No soul. No nothing. Even then, an “unethical” human, one who lives “on the wild side,” would be continually putting his life in danger. Since survival is undisputably the main objective of a purely biological being, a person who “enjoys living dangerously” would still be considered to be a “defunct human,” to say the least. He would be continually jeopardizing his survival and risking the chance of taking himself out of the gene pool.

Sound absurd to you? I don’t have any proof, but maybe this sounds so absurd because this ISN’T how people exist. Or perhaps a person who “enjoys living dangerously” has simply developed a mental callous. Even animals can come to accept and expect to live in a convoluted manner. Who’s to say the same cannot happen for a human?

Descartes also posited that this “good sense” is evenly distributed among human beings. So if one person were to indisputably arrive at what is correct for him, and find no errors, then it would apply to everyone. So I guess we have to try to find out of living in a peaceful manner is ALWAYS preferable to living in a chaotic manner. And we also have to find out if a person who says they enjoy living in a chaotic manner REALLY does enjoy it, or if he has somehow become a convolusion of what it is to be a human. These are monumental tasks.