sentences:  Barlaam held this concept to be polytheistic, inasmuch as it postulated two eternal substances, a visible (immanent) and an invisible God (transcendent).On the Hesychast side, the controversy was taken up by Antonite St Gregory Palamas, afterwards Archbishop of Thessalonica, who was asked by his fellow monks on Mt Athos to defend Hesychasm from Barlaam's attacks.St Gregory was well-educated in Greek philosophy (dialectical method) and thus able to defend Hesychasm.