But even with our best endeavors we need a helping hand now and then, and, indeed, are continuously dependent upon the work and kindness of others for all that makes life tolerable, or even possible.  And the other side to this truth is that we are never free from the obligation of doing our duty squarely by those whose welfare is in some degree dependent upon us.  No man can, if he would, live to himself alone; life is necessarily and essentially social.  Personal and social duties are so inextricably interwoven that it is impossible except by an artificial abstraction to separate them.  The cultivation of one’s own health, for example, is a boon to the community; and to care for the community’s health is to safeguard one’s own.  Every advance in personal purity, culture, or self-control increases the individual’s value and diminishes his menace to his fellows; while every step in social amelioration makes life freer and more comfortable for him.  So close- knit is society today that an indifference to sanitation in Asia or a religious persecution in Russia may produce disastrous results to some innocent and utterly indifferent individual in Massachusetts or California.  On the other hand, there is no vice so solitary and so can widespread social results. [Footnote:  Cf.  George Eliot in Adam Bede:  “There is no sort of wrong deed of which a man can bear the punishment alone.  Men’s lives are as thoroughly blended as the air they breathe; evil spreads as necessarily as disease.”] Society has a vital interest in the personal life of its members, and every member, however self- contained he may be, has a vital interest in the general standards of morality.  For purposes of analysis, however, it is convenient to make the distinction between the two aspects of morality, the governance of intra-human and of inter-human relations; the ordering of the single life and the ordering of the community life.  Of the two the latter is even more imperative than the former, the arbitration of clashes between individuals even more difficult than the governing of the impulses within a single heart.  We turn, therefore, to consider the problems involved in the general conception of social morality, which we may define as the direction of the action of each toward the greatest attainable welfare of all.  Why should we be altruistic?  That altruism (action directed toward others’ welfare) is best for the community as a whole is obvious.  In order to maintain his life in the face of the many obstacles that thwart and dangers that threaten him, man must present a solid front to the universe.  All clashes of interest, friction, and civil strife, all withholding of help, means a weakening of his united forces, an invitation to disaster.  And even where life becomes relatively secure and individualism possible, the greatest good for the greatest number is attainable only by continual cooperation and mutual sacrifice.  So vital is it to each member of the community that selfishness and cruelty in others be