Page:The System of Nature.djvu/72

 fit for the sustenance of man, whilst others destroy his existence: some are pleasant to him, strengthen his habit; others are repugnant to him, weaken his system: in short, never to separate physical from moral laws, it is thus that men, mutually attracted to each other by their reciprocal wants, form those unions which we designate by the terms, MARRIAGE, FAMILIES, SOCIETIES, FRIENDSHIPS, CONNEXIONS: it is thus that virtue strengthens and consolidates them; that vice relaxes or totally dissolves them.

Of whatever nature may be the combination of beings, their motion has always one direction or tendency: without direction we could not have any idea of motion: this direction is regulated by the properties of each being; as soon as they have any given properties, they necessarily act in obedience to them: that is to say, they follow the law invariably determined by these same properties; which, of themselves, constitute the being such as he is found, and settle his mode of action, which is always the consequence of his manner of existence. But what is the general direction, or common tendency, we see in all beings? What is the visible and known end of all their motion? It is to conserve their actual existence&mdash;to preserve themselves&mdash;to strengthen their several bodies&mdash;to attract that which is favorable to them&mdash;to repel that which is injurious them&mdash;to avoid that which can harm them&mdash;to resist impulsions contrary to their manner of existence, and to their natural tendency.

To exist, is to experience the motion peculiar to a determinate essence: to conserve this existence, is to give and receive that motion from which results its maintenance:&mdash;