egoism

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The doctrine that human behavior is motivated by self-interest.
• noun The belief that self-interest provides the proper basis for moral behavior.
• noun Egotism; conceit. synonym: conceit.

from The Century Dictionary.

• noun The habit of valuing everything only in reference to one's personal interest; pure selfishness or exclusive reference to self as an element of character.
• noun In ethics, the doing or seeking of that which affords pleasure or advantage to one's self, in distinction to that which affords pleasure or advantage to others: opposed to altruism. In this sense the term does not necessarily imply anything reprehensible, and is not synonymous with egotism.
• noun In metaphysics, the opinion that no matter exists and only one mind, that of the individual holding the opinion.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Philos.) The doctrine of certain extreme adherents or disciples of Descartes and Johann Gottlieb Fichte, which finds all the elements of knowledge in the ego and the relations which it implies or provides for.
• noun Excessive love and thought of self; the habit of regarding one's self as the center of every interest; selfishness; -- opposed to altruism.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The tendency to think of self and self-interest.
• noun ethics The belief that moral behavior should be directed toward one's self-interest.
• noun nonstandard, by confusion of the similar words egotism

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (ethics) the theory that the pursuit of your own welfare in the basis of morality
• noun concern for your own interests and welfare