5705. NATURE, Units in.—
Nature has,
in truth, produced units only through all her
works. Classes, orders, genera, species, are
not of her work. Her creation is of individuals.
No two animals are exactly alike; no
two plants, nor even two leaves or blades of
grass; no two crystallizations. And if we May
venture from what is within the cognizance of
such organs as ours, to conclude on that beyond
their powers, we must believe that no two
particles of matter are of exact resemblance.
This infinitude of units or individuals being
far beyond the capacity of our memory, we are
obliged, in aid of that, to distribute them into
masses, throwing into each of these all the
individuals which have a certain degree of resemblance;
to subdivide these again into
smaller groups, according to certain points of
dissimilitude observable in them, and so on
until we have formed what we call a system of
classes, orders, genera, and species. In doing
this, we fix arbitrarily on such characteristic
resemblances and differences as seem to us
most prominent and invariable in the several
subjects, and most likely to take a strong hold
in our memories.—
To Dr. John Manners. Washington ed. vi, 319.
(M.
1814)
