Is light particle and wave at the same time?

“You must bear in mind that the antagonisms that arise, above all the hostile personalities, are really, for the most part, puppets of the opposing Powers. For we are here in the field of activity of super-sensible Powers. These super-sensible Powers, to which Lucifer and Ahriman belong, naturally work in human life through human souls, which are simply their instruments.

Hence it is necessary to know exactly what is at issue in the one case or the other; but what is far and away the most necessary of all is that the acquisition of the faculty of clear, exact thinking shall never be neglected. You know that life itself has its contradictions, and Hegel built up his whole philosophy on this. It is not a question of avoiding the contradictions in life, for they are there. The essential thing is to recognise and be alert to them.

Ahriman and Lucifer can accomplish something only when a contradiction remains unnoticed, when we have neither the strength nor the will to lay it bare. Whenever we get entangled in a contradiction that we do not recognise as such but simply regard it as a natural part of life, this makes it possible for Lucifer and Ahriman to take possession of our soul.”

Rudolf Steiner

https://rsarchive.org/Lectures/GA254/English/RSP1973/19151019p01.html