'To make plain what that really means in human conduct, we must recall the character of that process by which man turns the forces of nature to his service instead of allowing them to overwhelm him. Its essence is a union of individual forces against the common enemy, the forces of nature. Where men in isolated action would have been powerless, and would have been destroyed, union, association, co-operation, enabled them to survive. Survival was contingent upon the cessation of struggle between them, and the substitution therefor of common action. Now, the process both in the beginning and in the subsequent development of this device of co-operation is important. It was born of a failure of force. If the isolated force had sufficed, the union of force would not have been resorted to. But such union is not a mere mechanical multiplication of blind energies; it is a combination involving will, intelligence. If mere multiplication of physical energy had determined the result of man's struggles, he would have been destroyed or be the helpless slave of the animals of which he makes his food. He has overcome them as he has overcome the flood and the storm--by quite another order of action. Intelligence only emerges where physical force is ineffective. 'There is an almost mechanical process by which, as the complexity of co-operation grows, the element of physical compulsion declines in effectiveness, and is replaced by agreement based on mutual recognition of advantage. There is through every step of this development the same phenomenon: intelligence and agreement only emerge as force becomes ineffective. The early (and purely illustrative) slave-owner who spent his days seeing that his slave did not run away, and compelling him to work, realised the economic defect of the arrangement: most of the effort, physical and intellectual, of the slave was devoted to trying to escape; that of the owner, trying to prevent him. The force of the one, intellectual or physical, cancelled the force of the other, and the energies of both were lost so far as productive value was concerned, and the needed task, the building of the shelter or the catching of the fish, was not done, or badly done, and both went short of food and shelter. But from the moment that they struck a bargain as to the division of labour and of spoils, and adhered to it, the full energies of both were liberated for direct production, and the economic effectiveness of the arrangement was not merely doubled, but probably multiplied many times. But this substitution of free agreement for coercion, with all that it implied of contract, of "what is fair," and all that followed of mutual reliance in the fulfilment of the agreement, was _based upon mutual recognition of advantage_.