The philosophy of those following the teachings of Epicurus.

Epicureans are materialists. They believe the universe is mechanical and made of material, based on Democritus' Atomism. Later Epicureans, i.e. Lucretius, add the Doctrine of the Swerve.* The aim of life is to gain pleasure (this is good) and avoid pain (bad!).

Contrary to what some may believe this implies, Epicurus was not a hedonist, at least in the typical sense of the word. Today, many associate Epicurean philosophy with the saying, "Eat, drink, and be merry!" but the philosophies are not quite the same. Essential to the philosophy of Epicurus was his recognition of a compatibility of pleasures. For example, eating a piece of cheesecake can be a pleasurable experience. What Epicureanism DOES advocate is nothing in excess because pleasure becomes pain if carried too far. Eating the entire cheesecake (particularly in one sitting) can lead to a painful stomachache.

Also, avoid physical pleasures such as sex, which leads to fatigue, remorse and depression. No pleasure is in itself bad; it is only the consequences that are associated with it that are problematic. Epicureanism focused on intellectual pleasures, which don't have all the negative side effects that the physical ones do.

Worries about the supernatural inhibit having a good life. If there are gods clearly they are indifferent to humans. Avoid religion. Or believe in gods, then forget about them. The end goal of all human action should be ataraxia, the imperturbability of mind and body. An intellectual tranquility very similar to Aristotle's Eudaimonia. Only through self-restraint, moderation, and detachment can one achieve the kind of tranquility that is true happiness.

Eight Epicurean counsels for today:

Don't fear God.
Don't worry about death.
Don't fear pain.
Live simply.
Pursue pleasure wisely.
Make friends and be a good friend.
Be honest in your business and private life.
Avoid fame and political ambition.
* The Doctrine of the swerve is the early atomists atempt to avoid the problem of determination inherent in any simple material and mechanistic metaphysical theory.