The morality of nature is clear, it is evident even to those who outrage it. It is not thus with superstitious morality; this is as obscure as the systems which prescribe it; or rather as fluctuating as the passions, as changeable as the temperaments, of those who expound them; if it was left to the theologians, ethics ought to be considered as the science of all others the most problematical, the most unsteady, the most difficult to bring to a point; it would require the most profound, penetrating genius, the most active, vigorous mind, to discover the principles of those duties man owes to himself, that he ought to exercise towards others; this would render the sources of the moral system attainable by a very small number of individuals; would effectually lock them up in the cabinets of the metaphysicians; place them under the treacherous guardianship of priests: to derive it from those systems, which are in themselves undefinable, with the foundations of which no one is actually acquainted, which each contemplates after his own mode, modifies after his own peculiar ideas, is at once to submit it to the caprice of every individual; it is completely to acknowledge, we know not from whence it is derived, nor whence it has its principles. Whatever may be the agent upon whom they make nature, or the beings she contains, to depend; with whatever power they way suppose him invested, it is very certain that man either does, or does not exist; but as soon as his existence is acknowledged, as soon as it is admitted to be what it actually is, when he shall be allowed to be a sensible being living in society, in love with his own felicity, they cannot without either annihilating him, or new modelling him, cause him to exist otherwise than he does. Therefore, according to his actual essence, agreeable to his absolute qualities, conformable to those modifications which constitute him a being, of the human species, morality becomes necessary to him, and the desire of conserving himself will make him prefer virtue to vice, by the same necessity that he prefers pleasure to pain. If, following up the doctrine of the theologians, "that man hath occasion for supernatural grace to enable him to do good," it must be very injurious to sound principles of morality; because he will always wait for "the call from above," to exercise that virtue, which is indispensable to his welfare. Tertullian, nevertheless says expressly, "wherefore will ye trouble yourselves, seeking after the law of God, whilst ye have that which is common to all the world, and which is written on the tablets of nature?"