The belief that there is one and only one truth; those who espouse absolutism usually also believe that they know what this absolute truth is. In ethics, absolutism is usually contrasted to relativism.

An act utilitarian holds that an action is right or wrong according to the quantity of pleasure (hedonistic act utiltarian) or happiness (eudaimonistic act utilitarian) it produces.

The conviction that one simply does not know whether God exists or not; it is often accompanied with a further conviction that one need not care whether God exists or not.

A selfless concern for other people purely for their own sake. Altruism is usually contrasted with selfishness or egoism in ethics.

The Greek word for excellence or virtue. For the Greeks, this was not limited to human beings. A guitar, for example, has its arete in producing harmonious music, just as a hammer has its excellence or virtue in pounding nails into wood well. So, too, the virtue of an Olympic swimmer is in swimming well, and the virtue of a national leader lies in motivating people to work for the common good.

The belief that God does not exist. In the last two centuries, some of the most influential atheistic philosophers have been Karl Marx, Friedrich Nietzsche, Bertrand Russell, and Jean-Paul Sartre.

The ability to freely determine one's own course in life. Etymologically, it goes back to the Greek words for self and law. This term is most strongly associated with Immanuel Kant, for whom it meant the ability to give the moral law to oneself.

A calculus is simply a means of computing something, and a moral calculus is just a means of calculating what the right moral decision is in a particular case.

An unconditional command. For Immanuel Kant, all of morality depended on a single categorical imperative. One version of that imperative was: Always act in such a way that the maxim of your action can be willed as a universal law.

Cognitivism means moral facts exist either as facts about the observable world or human nature and can be known and tested.

The belief that both determinism and freedom of the will are true.

Any position in ethics which claims that the rightness or wrongness of actions depends on their consequences.

The cosmological argument or first cause argument is that everything has a cause, causal chains cannot be infinite, so there must be an uncaused cause at its origin. Thomas Aquinas' version: contingent beings are insufficient to account for the existence of contingent beings: there must exist a necessary being whose non-existence is an impossibility, and from which the existence of all contingent beings is derived.

An example which claims to undermine or refute the principle or theory against which it is advanced.

See: Relativism