Knowledge and action: the role of sensationist philosophy
The reference to sensationism is an important element of “philosophie economique” - Boisguilbert had of course no contact with this philosophy but his theological point of departure leads to the same conclusions as regards individuals’ behaviour and political economy.
It represented an important line of development for the old discourse on the passions, interest and self-love. On the one hand, sensationism allowed them to be harmonised. One passion might create good or evil, pleasure or pain: passions can therefore be dealt with in terms of their positive or negative consequences, both individually and collectively. On the other hand, the power of human reason, while praised, was also recognised to be imperfect - if only, as Boisguilbert insisted in a traditional way, because original sin enfeebled its powers and enslaved people to their self-love. Knowledge consequently became problematic: it was impossible to know the essential nature of things. To escape this situation, however, it was possible to be guided by clear rules which were supposed to prevent reason from being led astray - the philosophy of Descartes and the Port-Royal La logique, ou l’art de penser (Arnaud and Nicole 1662), for example, provided such rules. However, it was also possible to resort to experience and experimentation, and limit oneself to the knowledge of more or less regular phenomena and their relationships, in the traditional sciences such as physics and astronomy, for example, as well as in the novel “moral and political sciences”: “we only know relationships. Wishing to say more is to confuse the limits of our spirit with that of nature” (Turgot 1750 [1913]: 168). In this perspective, the development of probability theory (to which the Port Royal Logique also contributed) and a probabilistic vision of science - from Christiaan Huygens (1629-1695) and Blaise Pascal (1623-1662) to Condorcet and Pierre-Simon de Laplace (1749-1827) - marked the eighteenth century. So did sensationism: based on John Locke’s Essay Concerning Human Understanding (1690), which was translated into the French language by Pierre Coste and saw many editions throughout the century, sensationist philosophy was developed by Condillac in Essai sur l’origine des connaissances humaines (Bonnot de Condillac 1746) and Traite des sensations (1754). This approach generated the sensationist political economy of Quesnay, Turgot and Condorcet, and the so-called French materialistic thought of Helvetius and d’Holbach.Quesnay’s article “Evidence” in the Encyclopedie showed that sensationism served as the foundation for an empirical theory of knowledge unencumbered by the mind/body dualism of the Cartesians. This new sensationism led to the idea that it is the utility of an action (the agreeable or disagreeable sensations) which determined behaviour (Quesnay 1756: para. 24); nevertheless, for Quesnay and the Physiocrats this approach was associated with the idea of a natural order. This meant that seeking the useful is not the criterion for the discovery of the good, but only the means of reaching it. In the socio-political construction of “legal despotism”, the norm of economic government is fixed in the natural order, but it is the harmony of interests between different classes that permitted its realisation.
Turgot and Condorcet’s approach is different: they rejected the idea of legal despotism. In their view, sensationism establishes fundamental natural human rights - liberty, security and property. It also serves to found a theory of subjective value based on utility and explain the determination of equilibrium prices in free markets. Upon the same foundation there also rested notions of justice and morality which, with the effective realisation of free trade, must guide the political and administrative organisation of the country.
The position of Helvetius and of d’Holbach is also different. They did not develop a theory of self-interested behaviour in markets under competitive conditions, but traced all behaviour to a calculation of pleasures and pains. In a society where economic activity played a significant part, this calculation involved a love of money which, since it permitted the reduction of pain and the increase of pleasure, became the most common passion of all. Deprivation of such a passion in such a society would remove any principle of action (Helvetius 1773, II: 580).