The last of the group of sources based on the concept of relationship is that of contraries. The argument from contraries implies that if we are benefiting from a certain fact or situation, then the contrary of the fact or situation will injure us; or, if we are being injured by the situation now existing, we can expect to be benefited by a situation contrary to it. In other words, my present failure or dissatisfaction implies the desirability of the contrary of what I now have; e.g., if we are suffering from war, what we need is peace. If Russia is pleased with the result of our policy in Asia, then what we need is a policy contrary to our present one, and so on.
One of the most interesting examples of the argument from contraries may be found in the “back to nature” movement of the eighteenth century. In this period there developed a highly formal culture, and a number of its prominent thinkers believed that it was suffering from too much formalism. In consequence, there appeared many pleas for a return to a more primitive or natural mode of life, together with admiration for people like the American Indians, who were thought to be unspoiled by civilization. Analysis shows that the “back to nature” movement rested on the following argument: if what we are suffering from is too much artificiality, then what we need is a return to the natural; or, if civilization is the source of our distresses, then we can expect to be benefited by its contrary. This produced an idealization of the primitive, and a desire to recapture the simple and unaffected life such as one encounters in the poetry of Wordsworth.