There are many ethical theories in Western philosophical thought, but the three most dominant are utilitarianism, deontology, and virtue ethics.

Utilitarianism is a consequentialist theory, which means that it judges the morality of an action based on its consequences. The most famous utilitarian philosopher is Jeremy Bentham, who argued that the morally right action is the one that produces the greatest happiness for the greatest number of people.

Deontology is a non-consequentialist theory, which means that it judges the morality of an action based on the action itself, rather than its consequences. The most famous deontological philosopher is Immanuel Kant, who argued that there are certain moral duties that we must follow, regardless of the consequences.

Virtue ethics is a theory that focuses on the character of the person who is acting, rather than the action itself. The most famous virtue ethicist is Aristotle, who argued that the morally good person is someone who has developed the virtues of courage, temperance, justice, and prudence.

These are just three of the many ethical theories that have been developed in Western philosophy. Each theory has its own strengths and weaknesses, and there is no one theory that is universally accepted. Ultimately, each individual must decide for themselves which ethical theory they find most convincing.

Here is a table that summarizes the key features of each ethical theory: