Looking at life and man from his own special point of view, he saw in the study of the physical organism the key to the intellectual and moral improvement of the race.
It is by knowledge of the relations between his physical states and moral states that man can attain happiness, through the enlargement of his faculties and the multiplication of enjoyments, and that he will be able to grasp, as it were, the infinite in his brief existence by realising the certainty of indefinite progress.

His doctrine was a logical extension of the theories of Locke and Condillac.

If our knowledge is wholly derived from sensations, our sensations depend on our sensory organs, and mind becomes a function of the nervous system.
The events of the Revolution quenched in him as little as in Condorcet the sanguine confidence that it was the opening of a new era for science and art, and thereby for the general Progress of man.

"The present is one of those great periods of history to which posterity will often look back" with gratitude.

[Footnote: Picavet, Les Ideologues, p.