Diderot philosophe (review)

Diderot's thought has often been believed to be full of incoherencies and paradoxes, lacking the unity characteristic of philosophical systems. It is true that he preferred the form of a dialogue to that of a systematic treatise and that his ideas on a specific subject tend to be dispersed in a variety of philosophical, literary or epistolary texts. However, the different pieces fit together nicely, if one has the patience to put them together. In his new monograph Colas Duflo manages to show the coherence and unity of Diderot's philosophy, not only by showing the consistency of the philosopher's thought on epistemological, aesthetical and moral subjects separately, but also by showing the close interdependence of different aspects of his philosophical inquiry and their grounding in his biological materialism.

Before the author examines Diderot's philosophy proper, he introduces the reader to Diderot's manner of writing and shows how the literary forms in which the encyclopedist presented his philosophy are indistinguishable from its content. Diderot did not write dialogues just in order to present in a palatable and entertaining form a philosophy that could well have been presented in erudite treatises. Dialogue was the original form of Diderot's thought. It helped him to distance himself from his thoughts and to put his ideas in a dialogue with each other, instead of systematizing them. In his dialogues the truth is approached by multiplying perspectives instead of being viewed from a central perspective which unifies the various points of view in one vision. Reminding the reader of this aspect of Diderot's philosophy is important. One would look in vain for the traditional mouthpiece of the truth among the protagonists of his dialogues; and this is true even in cases when he stages himself among them.

Colas Duflo starts his discussion of Diderot's philosophy by examining the philosopher's complex and changing relation to metaphysical finalism in his first philosophical works. Duflo also lets this theme of finalism run through the book as the main thread, which provides a coherent framework for the treatement of the different aspects of Diderot's philosophy. The presentation of Diderot's early writings situates these works in their contemporary context and manages to reveal the internal logic of Diderot's development from a finalist deist to an antifinalist atheist in a convincing manner. The chapter dealing with Le rêve de d'Alembert provides a careful and well-thought-out reading of this work and shows the originality of Diderot's biological materialism, which has really nothing to do with the mechanism sometimes falsely attributed to him (and to La Mettrie). Diderot's thought was not so much rooted in the mechanical world-view as it was in the sciences of life of his time. In relation to the problem of unity vs. multiplicity in Diderot's organicistic materialism, Duflo tends to emphasize multiplicity. One could, in fact, with as much reason, argue the opposite and put the emphasis on unity. But this is perhaps a matter of taste, since Diderot's originality lies in fact in his ability to take into account both aspects of the organisms by describing the continuing tensions between unifying and disrupting forces at work within them.

The part of the book dealing with aesthetics places the encyclopedist's theory of taste in the context of his materialism. The interpretations proposed are convincing although one has to take account of the fact that Duflo uses the word "spontaneous," not in its usual sense referring to immediate and unreflected reactions, but rather as a synonym of innate (see 303). Diderot emphasized the former but denied the latter. The juxtaposition of Diderot's aesthetics with that of Kant provides some enlightening insights into both. From taste one passes fluently to Diderot's moral philosophy: according to Diderot moral judgements resemble those of taste in so far as they are often as spontaneous as the latter. And despite this they are not innate but based on experience.

The chapters dealing with the moral and political philosophy of...