e combination, as they
approach one another, of analogous and similar molecules, up to the sun,
that vast reservoir of heated particles that gives light to the
firmament; from the numb oyster up to man--we observe an uninterrupted
progression, a perpetual chain of combination and movements, from which
there result beings that only differ among one another by the variety of
their elementary matters, and of the combination and proportion of these
elements. From this variety springs an infinite diversity of ways of
existing and acting. In generation, nutrition, preservation, we can see
nothing but different sorts of matter differently combined, each of them
endowed with its own movements, each of them regulated by fixed laws
that cause them to undergo the necessary changes.

Let us notice here three of the author's definitions. (1.) _Motion is an
effort, by which a body changes or tends to change its place._ (2.) Of
the ultimate composition of Matter, Holbach says nothing definite,
though he assumes molecular movement as its first law. He contents
himself, properly enough perhaps in view of the destination of his
treatise, with a definition "relatively to us." Relatively to us, then,
_Matter in general is all that affects our senses in any fashion
whatever; and the qualities that we attribute to different kinds of
matter, are founded on the different impressions that they produce on
us_. (3.) "When I say that Nature produces an effect, I do not mean to
personify this Nature, which is an abstraction; I mean that the effect
of which I am speaking is the necessary result of the properties of some
one of those beings that compose the great whole under our eyes. Thus,
when I say that Nature intends man to work for his own happiness, I mean
by this that it is of the essence of a being who feels, thinks, wills,
and acts, to work for his own happiness. By Essence I mean that which
constitutes a being what it is, the sum of its properties, or the
qualities according to which it exists and acts as it does."

_All phenomena are necessary._ No creature in the universe, in its
circumstances and according to its given property, can act otherwise
than as it does act. Fire necessarily burns whatever combustible matter
comes within the sphere of its action. Man necessarily desires what
either is, or seems to be, conducive to his comfort and wellbeing. There
is no independent energy, no isolated cause, no detached activity, in a
universe w