One of the leading figures of the French Enlightenment period, Condillac is the author of three highly influential books, published between 1746 and 1754, in which he attempted to refine and expand the empirical method of inquiry so as to make it applicable to a broader range of studies than hitherto. In the half-century following the publication of Newton’s Principia Mathematica in 1687, intellectual life in Europe had been engaged upon a fierce debate between the partisans of Cartesian physics, who accepted Descartes’ principles of metaphysical dualism and God’s veracity as the hallmark of scientific truth, and those who accepted Newton’s demonstration that the natural order constituted a single system under laws which could be known through painstaking observation and experiment. By the mid-eighteenth century Newton had gained the ascendancy, and it was the guiding inspiration of the French thinkers, known collectively as the philosophes, to appropriate the methods by which Newton had achieved his awesome results and apply them across a broader range of inquiries in the hope of attaining a similar expansion of human knowledge. Condillac was at the centre of this campaign.
Condillac’s first book, An Essay on the Origin of Human Knowledge (1746), bears the subtitle A Supplement to Mr. Locke’s Essay on the Human Understanding. While Condillac is usually seen as merely a disciple and popularizer of Locke offering little of any genuine originality, and while he did indeed agree with Locke that experience is the sole source of human knowledge, he attempted to improve on Locke by arguing that sensation alone – and not sensation together with reflection – provided the foundation for knowledge. His most famous book, the Treatise on the Sensations (1754) is based upon the thought-experiment of a statue whose senses are activated one by one, beginning with the sense of smell, with the intention of showing how all the higher cognitive faculties of the mind can be shown to derive from the notice the mind takes of the primitive inputs of the sense organs. Condillac also went beyond Locke in his carefully argued claims regarding the extent to which language affects the growth and reliability of knowledge. His Treatise on Systems (1749) offers a detailed critique of how language had beguiled the great seventeenth-century systems-builders like Descartes, Leibniz and Spinoza and led them into erroneous conceptions of the mind and human knowledge, the influence of which conceptions was as insidious as it was difficult to eradicate.
Skeptical Theism and the Threshold Problem
