St Gregory Palamas (ca 1296-1357), in stressing the Image of God in man, like many before him finds reflections of the Holy Trinity in the human soul. In particular he traces some analogies between the three Holy Persons and the human intellect, reason and spirit (νοῦς, λόγος, πνεῦμα). Palamas' sources for such analogies are a matter of scholarly discussion. The most plausible include Gregory Nazianzen, Augustine, Maximos the Confessor, John Damascene and, more immediately in Palamas' case, Gregory the Sinaite and Theoleptos of Philadelpheia. But, in recent scholarship, two other sources have been suggested as the most possible ones: Symeon the New Theologian and, his disciple, Niketas Stethatos (10th-11th century). This paper will test this hypothesis, which, at first glance, gives the impression of solving a difficult problem, i.e. what exactly Palamas' source is. Thus, the paper will analyze the approach of these two authors and compare it with that of Palamas. In conclusion, it will be shown that, despite common points, the differences on this issue between Symeon and Niketas on the one hand and Gregory Palamas on the other preclude any definitive argument of dependence.