remembered that we arbitrarily threw an arrow from D to A, thus making
what was hitherto an end become a means to its own means. Was this
legitimate? Does any such closed circle exist?

It certainly does not. Our universe contains nothing that can be
represented by that figure. Indeed if anywhere such a self-sufficing
organism did exist, we could never know it. For, by the hypothesis, it
would be altogether adequate to itself and without relations beyond
its own bounds. And if it were thus cut off from connection with
everything except itself, it could not even affect our knowledge. It
would be a closed universe within our universe, and be for us as good
as zero. We must own, then, that we have no acquaintance with any such
perfect organism, while the facts of life reveal conditions widely
unlike those here represented.

What these conditions are becomes apparent when we put significance
into the letters hitherto employed. Let our diagram become a picture
of the organic life of John. Then A might represent his physical life,
B his business life, C his civil, D his domestic; and we should have
asserted that each of these several functions in the life of John
assists all the rest. His physical health favors his commercial and
political success, while at the same time making him more valuable in
the domestic circle. But home life, civic eminence, and business
prosperity also tend to confirm his health. In short, every one of
these factors in the life of John mutually affects and is affected by
all the others.

But when thus supplied with meaning, Figure 3 evidently fails to
express all it should say. B is intended to exhibit the business life
of John. But this is surely not lived alone. Though called a function