Consciously or unconsciously he sought to produce what may be
designated as "pure cultures" of certain human qualities. But
these he took great pains to arrange in their proper psychological
settings, for mental and moral qualities, like everything else,
run in groups that are more or less harmonious, if not exactly
homogeneous. The man with a single quality, like Moliere's
Harpagon, was much too primitive and crude for Strindberg's art,
as he himself rightly asserted in his preface to "Miss Julia."
When he wanted to draw the genius of greed, so to speak, he did it
by setting it in the midst of related qualities of a kind most
likely to be attracted by it.

Tekla is such a "pure culture" of a group of naturally correlated
mental and moral qualities and functions and tendencies--of a
personality built up logically around a dominant central note.
There are within all of us many personalities, some of which
remain for ever potentialities. But it is conceivable that any one
of them, under circumstances different from those in which we have
been living, might have developed into its severely logical
consequence--or, if you please, into a human being that would be
held abnormal if actually encountered.

This is exactly what Strindberg seems to have done time and again,
both in his middle and final periods, in his novels as well as in
his plays. In all of us a Tekla, an Adolph, a Gustav--or a Jean
and a Miss Julia--lie more or less dormant. And if we search our
souls unsparingly, I fear the result can only be an admission
that--had the needed set of circumstances been provided--we might
have come unpleasantly close to one of those Strindbergian
creatures which we are now inclined to reject as unhuman.