Empiricism - The theory that all knowledge is obtained through the senses. We can never know more than what we can learn through the senses.
Rationalism - The theory that at least some knowledge is obtained through reason, unaided by the senses.
Epistemology - Literally, the study of knowledge. It is the study of how we come to know things, what the limits of our knowledge are, and with what certainty or uncertainty attaches to our knowledge.
Universality - Applying everywhere and always. It must be true for everyone if it is true for anyone.
Objective - True to the way the world really is, not merely reflecting the inner nature of an individual subject.
Paradigm - A frame of reference.
Ethics - The study of the way we ought to act.
Ethical Relativism - The theory that whether an act is right or wrong depends on the society in which one lives.
Ethical Skepticism - The doubt that any acts are right or wrong.
Ethical Nihilism - The denial that any acts are either right or wrong.
Categorical Imperative - An term invented by Immanuel Kant that refers to a command that orders us to do something unconditionally. We do this regardless of what we really want. It refers to the Highest Moral Law, according to Kant. “Act only on that maxim through which you can at the same time will that it should be a universal law.”
Utilitarianism - The moral theory that holds that everyone should always seek to produce the greatest happiness for the greatest number of people.
Laissez-faire/Captialism - An idea presented by Adam Smith in The Wealth of Nations that proposed that individuals could buy and sell freely in an open market with a minimum amount of government control and produce the best products for the lowest prices.
Social Contract - An idea proposed by Jean Jacques Rousseau that a group of people could set up a set of laws to live by. Each person would affirm acceptance of the contract and would be bound to it so long as they lived under the government. The United States of America is the first government to be established using this method.
General Will - An idea proposed by Jean Jacques Rousseau that people in a group will aim to do what is best for the group if they set aside personal interests. It has been observed that a group of people do not always act in the best interest of all the people. They act in the general good, but Rousseau was very pessimistic that a general will could be achieved.
Catharsis - Literally a cleansing. Aristotle argued that a powerful play could raise emotions such as fear to rise within us and be purged through the watching of the performance. The opposing view suggests that these emotions would not be present otherwise and thus th we should not partake of these performances.