Beyond the Lord and his Fire, the Gathas only recognize the archangels and certain ministers of Ormazd, who are, without exception, personifications of abstract ideas.
The great abstract ideas (considered directly and not merely in tacit use) which have dominated the science were due to them - namely, ratio, irrationality, continuity, the point, the straight line, the plane.
They express abstract ideas imperfectly.
But adaptation meant also reflection and the widening of old conceptions under the influence of thought and even of abstract ideas.
This, again, is a process of abstraction, the attainment of abstract ideas which, apart from the concrete individuals, are conceived as having a substantive existence.