Economic Imagination

Curvas de indiferença - F.Y.Edgeworth (1881)
Edgeworth - Mathematical Psychics (1881)

Every theory, Adam Smith teaches, is a way of imagining things. If there are systems which are preferable to others, it is because they explain, with a refinement and elegance of means which the others lack, diverse and complex phenomena, reduce them to a unified set of principles, and give them the appearance of a regularity and constancy without which they would elude our understanding. This observation, made in reference to astronomy, also applies to the emerging science of economics.