SAINT THOMAS AQUINAS                        375
these conditions as well as the events. He creates the whole, in one
act, complete, unchangeable, and it is then unfolded like a rolling
panorama, with its predetermined contingencies.
Man's free choice — liberum arbitrium — falls easily into place as
a predetermined contingency. God is the first cause, and acts in all
secondary causes directly ; but while He acts mechanically on the rest
of creation, — as far as is known, — He acts freely at one point, and
this free action remains free as far as it extends on that line. Man's
freedom derives from this source, but it is simply apparent, as far as
he is a cause ; it is a reflex action determined by a new agency of the
first cause.
However abstruse these ideas may once have sounded, they are far
from seeming difficult in comparison with modern theories of energy.
Indeed, measured by that standard, the only striking feature of Saint
Thomas's motor is its simplicity. Thomas's prime motor was very
powerful, and its lines of energy were infinite. Among these infinite
lines, a certain group ran to the human race, and, as long as the con-
duction was perfect, each man acted mechanically. In cases where the
current, for any reason, was for a moment checked, — that is to say,
produced the effect of hesitation or reflection in the mind, — the cur-
rent accumulated until it acquired power to leap the obstacle. As Saint
Thomas expressed it, the Prime Motor, Who was nothing else than
God, intervened to decide the channel of the current. The only differ-
ence between man and a vegetable was the reflex action of the com-
plicated mirror which was called mind, and the mark of mind was
reflective absorption or choice. The apparent freedom was an illusion
arising from the extreme delicacy of the machine, but the motive
power was in fact the same — that of God.
This exclusion of what men commonly called freedom was carried
still further in the process of explaining dogma. Supposing the con-
duction to be insufficient for a given purpose; a purpose which shall
require perfect conduction? Under ordinary circumstances, in ninety-