Do not let us mistake for real sciences, those which have no other basis than our imagination; we shall find that such can at most be but visionary: let us cling close to nature which we see, which we feel, of which we experience the action; of which at least we understand the general laws. If we are ignorant of her detail, if we cannot fathom the secret principles she employs in her most complicated productions, we are at least certain she acts in a permanent, uniform, analogous, necessary manner. Let us then observe this nature; let us watch her movements; but never let us endeavour to quit the routine she prescribes for the beings of our species: if we do, we shall not only be obliged to return, but we shall also infallibly be punished with numberless errors, which will darken our mind, estrange us from reason; the necessary consequence will be countless sorrows, which we may otherwise avoid. Let us consider we are sensible parts of a whole, in which the forms are only produced to be destroyed; in which combinations are ushered into life, that they may again quit it, after having subsisted for a longer or a shorter season. Let us look upon nature as an immense elaboratory which contains every thing necessary for her action; who lacks nothing requisite for the production of all the phenomena she displays to our sight. Let us acknowledge her power to be inherent in her essence; amply commensurate to her eternal march; fully adequate to the happiness of all the beings she contains. Let us consider her as a whole, who can only maintain herself by what we call the discord of the elements; that she exists by the continual dissolution and re-union of her parts; that from this springs the universal harmony; that from this the general stability has its birth. Let us then re-establish omnipotent nature, so long mistaken by man, in her legitimate rights. Let us place her on that adamantine throne, which it is for the felicity of the human race she should occupy. Let us surround her with those ministers who can never deceive, who can never forfeit our confidence--_Justice and Practical Knowledge_. Let us listen to her eternal voice; she neither speaks ambiguously, nor in an unintelligible language; she may be easily comprehended by the people of all nations; because _Reason_ is her faithful interpreter. She offers nothing to our contemplation but immutable truths. Let us then for ever impose silence on that enthusiasm which leads us astray; let us put to the blush that imposture which would riot on our credulity; let us discard that gloomy superstition, which has drawn us aside from the only worship suitable to intelligent beings. Above all, never let us forget that the temple of happiness can only be reached through the groves of virtue, which surround it on every side; that the paths which lead to these beautiful walks can only be entered by the road of experience, the portals of which are alone opened