To show how a fact is useful is not to explain how it was created or why it is as it is. The uses it serves presuppose the specific properties characterising it, but do not create them. The need we have of things cannot give them their specific nature, or cause them to come into being. It is to causes of another sort that they owe their existence. The idea we have of their utility may indeed motivate us to put these forces to work and to elicit from them their characteristic effects, but it will not enable us to produce these effects out of nothing. This proposition is evident so long as it is a question only of material, or even psychological, phenomena. It would be equally undisputed in sociology if social facts, because of their extreme intangibility, did not—mistakenly—appear to us without all intrinsic reality.