Value is a property of things, but different from that of colour or weight. In fact, the value of a thing derives substantially from the need or desires it is capable of satisfying. The greater this capacity is, the greater the value of the thing will be.Value is not a fixed and inherent property of things. It is rather a variable property, whose magnitude depends not only on the nature of the thing itself, but also on who evaluates it and the circumstances in which it is evaluated. Value is profoundly influenced by the cultural context. A thing can have different values according to different purposes, at different times, for different people, in different conditions and according to the different circumstances (personal, physical, psychological, cultural, social and political) of the assessor at the time when he evaluates. This implies, in turn, that if value does not exist in itself, but rather for the utility it produces, utility also exists because, and at the moment when, it is assessed as such.