Original sentence: Altruism is the principle and moral practice of concern for happyness of other human beings, resulting in a quality of life  both material and spiritual.In a common way of living, it doesn't deny the singular nature of the subject, but realizes the traits of the individual personality in relation to the others, with a true, direct and personal interaction with each of them.In an (not only) christian practice, it is the law of love direct to the ego and his neighbour.In extrene case, altruism may become a synonym of selflessness which is the opposite of selfishness.It is focusing both on the single people and the whole community.The word "altruism"  was coined by the French philosopher Auguste Comte in French, as altruisme, for an antonym of egoism
Edited sentence: Altruism or selflessness is the opposite of selfishness.Altruism or selflessness is the principle or practice of concern for the welfare of others.The word was coined by the French philosopher Auguste Comte in French, as altruisme, for an antonym of egoism