All strife directed towards obtaining advantages independently of other men, and in opposition to them, contradicts the social nature of modern man, and tends to lead it back to a more animal condition.
Solidarity, that is, harmony of interests and sentiments, the sharing of each in the good of all, and of all in the good of each, is the state in which alone man can be true to his own nature, and attain to the highest development and happiness. It is the aim towards which human development tends. It is the one great principle, capable of reconciling all present antagonisms in society, otherwise irreconcilable. It causes the liberty of each to find not its limits, but its complement, the necessary condition of its continual existence--in the liberty of all.
"No man," says Michael Bakunin, "can recognize his own human worth, nor in consequence realize his full development, if he does not recognize the worth of his fellow men, and in co-operation with them, realize his own development through them. No man can emancipate himself, unless at the same time he emancipates those around him. My freedom is the freedom of all; for I am not really free--free not only in thought, but in deed--if my freedom and my right do not find their confirmation and sanction in the liberty and right of all men my equals.
"It matters much to me what all other men are, for however independent I may seem, or may believe myself to be, by virtue of my social position, whether as pope, czar, emperor, or prime minister, I am all the while the product of those who are the least among men. If these are ignorant, miserable, or enslaved, my existence is limited by their ignorance, misery, or slavery. I, though an intelligent and enlightened man, am made stupid by their stupidity; though brave, am enslaved by their slavery; though rich, tremble before their poverty; though privileged, grow pale at the thought of possible justice for them. I, who wish to be free, cannot be so, because around me are men who do not yet desire freedom, and, not desiring it, become, as opposed to me, the instruments of my oppression."
Solidarity, then, is the condition in which man can attain the highest degree of security and of well-being. Therefore, egoism itself, that is, the exclusive consideration of individual interests, impels man and human society towards solidarity. Or rather egoism and altruism (consideration of the interests of others) are united in this one sentiment, as the interest of the individual is one with the interests of society.
However, man could not pass at once from animalism to humanity; from brutal strife between man and man to the collective strife of all mankind, united in one brotherhood of mutual aid against external nature.
Guided by the advantages that association and the consequent division of labor offer, man evolved towards solidarity, but his evolution encountered an obstacle which led him, and still leads him, away from his aim. He discovered that he could realize the advantages of co-operation, at least up to a certain point, and for the material and primitive wants that then comprised all his needs, by making other men subject to himself, instead of associating on an equality with them. Thus the ferocious and anti-social instincts, inherited from his bestial ancestry, again obtained the upper hand. He forced the weaker to work for him, preferring to domineer over rather than to associate fraternally with his fellows. Perhaps also in most cases it was by exploiting the conquered in war that man learnt for the first time the benefits of association and the help that can be obtained from mutual support.
Thus it has come about that the establishment of the utility of co-operation, which ought to lead to the triumph of solidarity in all human concerns, has turned to the advantage of private property and of government; in other words, to the exploitation of the labor of the many, for the sake of the privileged few.
There has always been association and co-operation, without which human life would be impossible; but it has been co-operation imposed and regulated by the few in their own particular interest.
From this fact arises a great contradiction with which the history of mankind is filled. On the one hand, we find the tendency to associate and fraternize for the purpose of conquering and adapting the external world to human needs, and for the satisfaction of the human affections; while, on the other hand we see the tendency to divide into as many separate and hostile factions as there are different conditions of life. These factions are determined, for instance, by geographical and ethnological conditions, by differences in economic position, by privileges acquired by some and sought to be secured by others, or by suffering endured, with the ever recurring desire to rebel.