in, Physiology, the abstract science, investigates, by such means as
are available to it, the general laws of organization and life. Those
laws determine what living beings are possible, and maintain the
existence and determine the phaenomena of those which actually exist:
but they would be equally capable of maintaining in existence plants and
animals very different from these. The concrete sciences, Zoology and
Botany, confine themselves to species which really exist, or can be
shown to have really existed: and do not concern themselves with the
mode in which even these would comport themselves under all
circumstances, but only under those which really take place. They set
forth the actual mode of existence of plants and animals, the phaenomena
which they in fact present: but they set forth all of these, and take
into simultaneous consideration the whole real existence of each
species, however various the ultimate laws on which it depends, and to
whatever number of different abstract sciences these laws may belong.
The existence of a date tree, or of a lion, is a joint result of many
natural laws, physical, chemical, biological, and even astronomical.
Abstract science deals with these laws separately, but considers each of
them in all its aspects, all its possibilities of operation: concrete
science considers them only in combination, and so far as they exist and
manifest themselves in the animals or plants of which we have
experience. The distinctive attributes of the two are summed up by M.
Comte in the expression, that concrete science relates to Beings, or
Objects, abstract science to Events.[2]

The concrete sciences are inevitably later in their development than the
abstract sciences on which they depend. Not that they begin later to be
studied; on the contrary, they are the earliest cultivated, since in our
abstract investigations we necessarily set out from spontaneous facts.
But though we may make empirical generalizations, we can form no
scientific theory of concrete phaenomena until the laws which govern and
explain them are first known; and those laws are the subject of the
abstract sciences. In consequence, there is not one of the concrete
studies (unless we count astronomy among them) which has received, up to
the present time, its final scientific constitution, or can be accounted
a science, except in a very loose sense, but only materials for science:
partly from insufficiency of facts, but more, becaus