hereas the actual progress consists in those internal modifications of
which this increased knowledge is the expression. Social progress is
supposed to consist in the produce of a greater quantity and variety of
the articles required for satisfying men's wants; in the increasing
security of person and property; in widening freedom of action: whereas,
rightly understood, social progress consists in those changes of
structure in the social organism which have entailed these consequences.
The current conception is a teleological one. The phenomena are
contemplated solely as bearing on human happiness. Only those changes
are held to constitute progress which directly or indirectly tend to
heighten human happiness. And they are thought to constitute progress
simply _because_ they tend to heighten human happiness. But rightly to
understand progress, we must inquire what is the nature of these
changes, considered apart from our interests. Ceasing, for example, to
regard the successive geological modifications that have taken place in
the Earth, as modifications that have gradually fitted it for the
habitation of Man, and as _therefore_ a geological progress, we must
seek to determine the character common to the modifications--the law to
which they all conform. And similarly in every other case. Leaving out
of sight concomitants and beneficial consequences, let us ask what
Progress is in itself.

In respect to that progress which individual organisms display in the
course of their evolution, this question has been answered by the
Germans. The investigations of Wolff, Goethe, and Von Baer, have
established the truth that the series of changes gone through during the
development of a seed into a tree, or an ovum into an animal, constitute
an advance from homogeneity of structure to heterogeneity of structure.
In its primary stage, every germ consists of a substance that is uniform
throughout, both in texture and chemical composition. The first step is
the appearance of a difference between two parts of this substance; or,
as the phenomenon is called in physiological language, a
differentiation. Each of these differentiated divisions presently begins
itself to exhibit some contrast of parts; and by and by these secondary
differentiations become as definite as the original one. This process is
continuously repeated--is simultaneously going on in all parts of the
growing embryo; and by endless such differentiations there is finally