A treatise on the analysis of thought ("Sur la décomposition de la pensée", "On the Decomposition of Thought") was never printed. In 1834 these writings, together with the essay entitled "Nouvelles considérations sur les rapports du physique et du moral de l'homme", were published by Victor Cousin, who in 1841 added three volumes, under the title "Œuvres philosophiques de Maine de Biran". But the publication (in 1859) by Édouard Naville (from manuscripts placed at his father's disposal by Biran's son) of the "Œuvres inédites de Maine de Biran", in three volumes, first rendered possible a connected view of his philosophical development. At first a sensualist, like Condillac and John Locke, next an intellectualist, he finally became a mystical theosophist. The "Essai sur les fondements de la psychologie" represents the second stage of his philosophy, the fragments of the "Nouveaux essais d'anthropologie" the third. Maine de Biran's early essays in philosophy were written from the point of view of Locke and Condillac, but showed signs of his later interests. Dealing with the formation of habits, he is compelled to note that passive impressions do not furnish a complete or adequate explanation. With Laromiguière he distinguishes attention as an active effort, of no less importance than the passive receptivity of sense, and like Joseph Butler, he distinguishes passively formed customs from active habits. He concluded that Condillac's notion of passive receptivity as the one source of conscious experience was an error of method – in short, that the mechanical mode of viewing consciousness as formed by external influence was fallacious and deceptive. For it he proposed to substitute the genetic method, whereby human conscious experience might be exhibited as growing or developing from its essential basis in connection with external conditions. The essential basis he finds in the real consciousness, of self as an active striving power, and the stages of its development, corresponding to what one may call the relative importance of the external conditions and the reflective clearness of self-consciousness he designates as the affective, the perceptive and the reflective. In connexion with this Biran treats most of the obscure problems which arise in dealing with conscious experience, such as the mode by which the organism is cognized, the mode by which the organism is distinguished from extra-organic things, and the nature of those general ideas by which the relations of things are known to us – cause, power, force, etc.