oul, but forsook
it because the soul would not follow it; yet it retained, as it were,
a spark of its power," etc. See also Tertullian, _De Anima_, 41. The
curious word _synteresis_ (often misspelt _sinderesis_), which plays a
considerable part in mediaeval mystical treatises, occurs first in
Jerome (on _Ezech._ i.): "Quartamque ponunt quam Graeci vocant [Greek:
synteresin], quae scintilla conscientiae in Cain quoque pectore non
exstinguitur, et qua victi voluptatibus vel furore nos peccare
sentimus.... In Scripturis [eam] interdum vocari legimus Spiritum."
Cf. Rom. viii. 26; 2 Cor. ii. 11. Then we find it in Alexander of
Hales, and in Bonaventura, who (_Itinerare_, c. I) defines it as "apex
mentis seu scintilla"; and more precisely (_Breviloquium, Pars_ 2, c.
11): "Benignissimus Deus quadruplex contulit ei adiutorium, scilicet
duplex naturae et duplex gratiae. Duplicem enim indidit rectitudinem
ipsi naturae, videlicet unam ad recte iudicandum, et haec est rectitudo
conscientiae, aliam ad recte volendum, et haec est synteresis, cuius est
remurmurare contra malum et stimulare ad bonum." Hermann of Fritslar
speaks of it as a power or faculty in the soul, wherein God works
immediately, "without means and without intermission." Ruysbroek
defines it as the natural will towards good implanted in us all, but
weakened by sin. Giseler says: "This spark was created with the soul
in all men, and is a clear light in them, and strives in every way
against sin, and impels steadily to virtue, and presses ever back to
the source from which it sprang." It has, says Lasson, a double
meaning in mystical theology, (a) the ground of the soul; (b) the
highest ethical faculty. In Thomas Aquinas it is distinguished from
"intellectus principiorum," the former being the highest activity of
the moral sense, the latter of the intellect. In Gerson, "synteresis"
is the highest of the affective faculties, the organ of which is the
intelligence (an emanation from the highest intelligence, which is God
Himself), and the activity of which is contemplation. Speaking
generally, the earlier scholastic mystics regard it as a remnant of
the sinless state before the fall, while for Eckhart and his school it
is the core of the soul.

There is another expression which must be considered in connexion with
the mediaeval doctrine of deification. This is the _intellectus agens_,
or [Greek: nous poietikos], which began its long history in
Aristotle (_De Anima_, iii