Thus, it is for want of consulting experience, by not attending to reason, that man has darkened his ideas upon the concealed principle of his motion. If, disentangled from prejudice--if, destitute of gratuitous suppositions--if, throwing aside error, he would contemplate his soul, or the moving principle that acts within him, he would be convinced that it forms a part of its body, that it cannot be distinguished from it, but by abstraction; that it is only the body itself, considered relatively with some of its functions, or with those faculties of which its nature, or its peculiar organization, renders it susceptible:--he will perceive that this soul is obliged to undergo the same changes as the body; that it is born with it; that it expands itself with it; that like the body, it passes through a state of infancy, a period of weakness, a season of inexperience; that it enlarges itself, that it strengthens itself, in the same progression; that like the body, it arrives at an adult age or reaches maturity; that it is then, and not till then, it obtains the faculty of fulfilling certain functions; that it is in this stage, and in no other, that it enjoys reason; that it displays more or less wit, judgment, and manly activity; that like the body, it is subject to those vicissitudes which exterior causes obliges it to undergo by their influence; that, conjointly with the body, it suffers, enjoys, partakes of its pleasures, shares its pains, is sound when the body is healthy, and diseased when the body is oppressed with sickness; that like the body, it is continually modified by the different degrees of density in the atmosphere; by the variety of the seasons, and by the various properties of the aliments received into the stomach: in short, he would be obliged to acknowledge that at some periods it manifests visible signs of torpor, stupefaction, decrepitude, and death. In despite of this analogy, or rather this continual identity, of the soul with the body, man has been desirous of distinguishing their essence; he has therefore made the soul an inconceivable being: but in order that he might form to himself some idea of it, he was, notwithstanding, obliged to have recourse to material beings, and to their manner of acting. The word _spirit_, therefore, presents to the mind no other ideas than those of breathing, of respiration, of wind. Thus, when it is said the _soul is a spirit_, it really means nothing more than that its mode of action is like that of breathing: which though invisible in itself, or acting without being seen, nevertheless produces very visible effects. But breath, it is acknowledged, is a material cause; it is allowed to be air modified; it is not, therefore, a simple or pure substance, such as the moderns designate under the name of SPIRIT.