• The manner in which things exist and take place, constitutes what is called the nature of things; and a careful observation of the nature of things is the sole foundation of all truth.

    Jean-Baptiste Say: The manner in which things exist and take place, constitutes what is called the nature of things; and a careful observation of the nature of things is the sole foundation of all truth.
    Jean Baptiste Say (1827). “A treatise on political economy: or, The production, distribution and consumption of wealth”, p.21