elf is; in short, that we might be able to solve in a
scientific way the old, old riddle of existence. But already we have
about reached the limits of the powers of the microscope; and even if we
could devise a way of seeing the ultimate structures of which protoplasm
is composed, how would we be any better off? Would we not have to
attribute to each constituent of this living substance the properties
which we now attribute to the whole?--that is, the properties which we
attribute to masses of protoplasmic units, such as plants, or birds, or
human beings?

We look at ourselves and we feel sure that we have a separate and real
existence, that we are rationally conscious and are endowed with choice
and free will. We can say almost as much for an intelligent bird or dog.
But we hesitate to say how many of these powers or characteristics of
free and independent personality can be assigned to the unicellular
organisms, such as the amoeba or the corpuscles of our blood. These
one-celled creatures are also alive, are just as truly alive as are
those composed of many cells. Even the corpuscles of which our bodies
are composed move, and eat, and grow, and seem really endowed with
intelligence like the higher forms of life. Suppose we could go further
than is now possible and could lay bare the ultimate make-up of the
_chromatin_ of these one-celled creatures, would we even then be able to
prove that life with all its properties is inherent in these material
components of the cells? In other words, would we really solve anything
after all? Or would we not rather be compelled to acknowledge that the
simplest, the most truly rational view of the question is that in living
matter we have merely a special manifestation of the presence and the
direct action of the God of nature which we cannot so readily recognize
in not-living matter? This, it seems to me, is all that we really know,
and all that we are likely ever to know.

When we examine carefully the differences between the living and the
not-living, we see that the chief difference between them is in _their
origin_. The matter of growth is not a real distinction; for crystals
grow on the outside, while inorganic liquids grow by intussusception, as
when a soluble substance is added to them, in very much the same way as
an animal grows by the ingestion of food. Even movement is hardly an
absolute distinction between the living and the not-living; for no
movement can be detected i