The reflections presented to the reader in this work, tend to shew what ought to be thought of the human soul, as well as of its operations and faculties: every thing proves, in the most convincing manner, that it acts, that it moves according to laws similar to those prescribed to the other beings of Nature; that it cannot be distinguished from the body; that it is born with it; that it grows up with it; that it is modified in the same progression; in short, every thing ought to make man conclude that it perishes with it. This soul, as well as the body, passes through a state of weakness and infancy; it is in this stage of its existence, that it is assailed by a multitude of modifications; that it is stored with an infinity of ideas, which it receives from exterior objects through the medium of the organs; that it amasses facts, that it collects experience, whether true or false, that it forms to itself a system of conduct, according to which it thinks, in conformity with which it acts, from whence results either its happiness or its misery, its reason or its delirium, its virtues or its vices; arrived with the body at its full powers, having in conjunction with it reached maturity, it does not cease for a single instant to partake in common of its sensations, whether these are agreeable or disagreeable; it participates in all its pleasures; it shares in all its pains; in consequence it conjointly approves or disapproves its state; like it, it is either sound or diseased; active or languishing; awake or asleep. In old age man extinguishes entirely, his fibres become rigid, his nerves loose their elasticity, his senses are obtunded, his sight grows dim, his ears lose their quickness, his ideas become unconnected, his memory fails, his imagination cools: what then becomes of his soul? Alas! it sinks down with the body; it gets benumbed as this loses its feeling; becomes sluggish as this decays in activity; like it, when enfeebled by years it fulfils its functions with pain; this substance, which is deemed spiritual, which is considered immaterial, which it is endeavoured to distinguish from matter, undergoes the same revolutions, experiences the same vicissitudes, submits to the same modifications, as does the body itself.