Reason may be a very small part of the apparatus of human conduct compared with the part played by the unconscious and subconscious, the instinctive and the emotional. The power of a ship's compass is very small indeed compared with the power developed by the engines. But the greater the power of the engines, the greater will be the disaster if the relatively tiny compass is deflected and causes the ship to be driven on to the rocks. The illustration indicates, not exactly but with sufficient truth, the relationship of 'reason' to 'instinct.' The instincts that push to self-assertion, to the acquisition of preponderant power, are so strong that we shall only abandon that method as the result of perceiving its futility. Co-operation, which means a relationship of partnership and give and take, will not succeed till force has failed. The futility of power as a means to our most fundamental and social ends is due mainly to two facts, one mechanical, and the other moral. The mechanical fact is that if we really need another, our power over him has very definite limits. Our dependence on him gives him a weapon against us. The moral fact is that in demanding a position of domination, we ask something to which we should not accede if it were asked of us: the claim does not stand the test of the categorical imperative. If we need another's labour, we cannot kill him; if his custom, we cannot forbid him to earn money. If his labour is to be effective, we must give him tools, knowledge; and these things can be used to resist our exactions. To the degree to which he is powerful for service he is powerful for resistance. A nation wealthy as a customer will also be ubiquitous as a competitor. The factors which have operated to make physical compulsion (slavery) as a means of obtaining service less economical than service for reward, operate just as effectively between nations. The employment of military force for economic ends is an attempt to apply indirectly the principle of chattel-slavery to groups; and involves the same disadvantages.[115] In so far as coercion represents a means of securing a wider and more effective social co-operation as against a narrower social co-operation, or more anarchic condition, it is likely to be successful and to justify itself socially. The imposition of Western government upon backward peoples approximates to the role of police; the struggles between the armed forces of rival Western Powers do not. The function of a police force is the exact contrary to that of armies competing with one another.[116]