It is generally conceded that the varied personages of the eighteenth-century conte philosophique are not sufficiently developed to merit the label of characters. Whether in satiric or in pleasant guise, they but project ideas. However, as the conte itself covered a multiplicity of fields and lent itself to a variety of interpretations, so do these personages, the various divisions of ‘philosophes,’ possess numerous phases or nuances. Even a casual reader of the philosophic tale will have met, in the array of types on parade—an oft-repeated “naïf” (who was anything but naïve), at least one famed “candide,” and several “ingénus.” Another of these types engaged in his journey, and one whom a reader can scarcely fail to encounter, is “le solitaire.” He too is evolved by formula, and for his special century. Representing a nuance of the ‘philosophe,’ he is fully as potent an individual as were ever his various brother “naïfs.” If one grants that certain familiar and well-tempered themes have traversed the Encyclopedic and Revolutionary era,—one might say correlatively that this “solitaire” has contributed his very effective share to the creation of one great thematic personage. This philosophe’ could be a variety of entities, each one in turn representing and including a rather set formula of characteristics. Some aspects of the “solitaire” formula for this era alone, are to be considered in the present study.