Another form of the word, "Egotism," is really interchangeable, though in ordinary language it is often used specially (and similarly "egoism," as in George Meredith's Egoist) to describe the habit of magnifying one's self and one's achievements, or regarding all things from a selfish point of view.
Thus the man who seeks only or primarily his own moral perfection is an egoist par excellence.
A practical theory of ethics seeks to establish a particular moral ideal; if it is an absolute criterion, then the altruist would place first the attainment of that ideal by others, while the egoist would seek it for himself.
The egoist and the altruist are both imperfect.
He flattered in turn Saint Just and the Terrorists, the Thermidorians and the Directors, and played always for his own hand - a strange egoist who rose to fame as the leader of an idealist and sentimental crusade.
Indeed, we may say that an egoist must be doubly self-regulative, since rational self-love ought to restrain not only other impulses, but itself also; for as happiness is made up of feelings that result from the satisfaction of impulses other than self-love, any over-development of the latter, enfeebling these other impulses, must proportionally diminish the happiness at which self-love aims. If, then, it be admitted that human impulses are naturally under government, the natural claim of conscience or the moral faculty to be the supreme governor will hardly be denied.