(Bulgakov 1991, 345–346 = Bulgakov 1926).

Recalling Sergius' natural gifts and education (in particular, Bartholomew's initial failure in mastering literacy), in particular, and Sergius' craving for enlightenment, his zeal for book education [429], the same author highlights Sergius' strong side, his intellect (which has already been partially written above):

We can guess about the natural mind of the monk only on the basis of a general impression of his entire life and many-sided activities. From all this we must conclude that St. Sergius belonged to the number of the most outstanding Russian minds: all his actions bear the stamp of a kind of fidelity and insight, of the highest wisdom, not only spiritual, but also civil and social.

(Bulgakov 1991, 347).

This is about the predispositions and capabilities of Sergius. Now let's talk about what Sergius could have learned about the Trinity, the Trinitarian dogma and the Trinitarian teaching. In the time of Sergius, these problems were most attractive to Greek theologians, both Gregory Palamas and his associates in hesychasm, and his opponents. The Palamites had something new. In their disputes with this new, primarily with Gregory Palamas, his opponents essentially returned to pre-Nicene theology, which considered the Father to be an inaccessible element of God, in contrast to the Son and the Spirit, the instruments of revelation (see Meyendorff 1997, 297). The final version of the theological teaching on the Trinity, formulated by Palamas and, of course, taking into account the idea of "consubstantiality" developed by the Cappadocians, was based on a threefold difference. Meyendorff 1997, 298–299 describes this variant as follows:

Three realities belong to God – essence, energy, the Trinity of Divine hypostases (τρίασος υποστάσεоν θείоν). We have seen that the personal, triune, nature of the Godhead is simplicity, while essence and energies signify the antinomic poles of the Incomprehensible, Self-Revealing, multiplying Unity, the only Existent who allows creatures to partake of His being. These distinctions are necessary for the teacher of silence in order to show "how God, who is partly contained in creatures, is wholly partaken of and contained without being divided (σύ μερίζεται)," for "Goodness is not a part of God, and Wisdom is another, and Majesty or Providence is another part, but He is wholly Goodness, wholly Wisdom, wholly Providence, and wholly Greatness, for, being one, He is not divided, but the whole possesses as a property of each of these energies and manifests Himself as whole, being present and acting in each in a single, simple and inseparable way (πρός ένιαίоς και άπλоς καί δλος παρών καί ένεργών)." […]

Any presence and any real action of God in the plural world presupposes a divine existence that is "multiplied."

The mystery of the Trinity, according to Gregory Palamas, is formed by "the union of three hypostases, each of which in reality preserves its personal identity, but are not 'parts' of God, for the Godhead lives in each of them in all His fullness" (Meyendorff 1997, 292) [431].

This summary of the Trinitarian teaching in the Palamite version, at least in its basis, could have been expounded by a Russian scribe of the "Hesychast-Palamite" circle, especially if he had been to Constantinople and communicated with the Palamites. Such a person could have presented this teaching at the level of a general "idea" to Sergius, especially since it is known that Sergius, and precisely in connection with theological questions, sent his people from the Trinity to Constantinople. Nothing is known about the results of this trip, but it could hardly have been completely fruitless, and Constantinople news, including theological news, was keenly interested both in Moscow and in the Holy Trinity, in the former – and mercenarily, having in mind practical benefit, in the latter, it seems, unselfishly. In any case, this is true of Sergius.

It is very likely that Sergius had certain information about the Trinitarian teaching of the Church Fathers and Gregory Palamas. Moreover, it is plausible that he himself was interested in Trinitarian theology and may have assimilated from this information something most likely corresponding to his own intuitions and his personal experience of thinking about God. It must be assumed that not all the subtleties were accessible to Sergius, but he was hardly upset, for he knew that the Trinity is a mystery that has no limit or end, and it cannot be revealed to the "finite" man in all its depth. However, it is necessary to know about this depth and about the incommensurability of this mystery with one's capabilities, and Sergius knew about this. It seems that Sergius also knew that, in measuring the incommensurable, one must find the direction of search that really leads deeper, and not sideways, and that it is also necessary to connect one's knowledge of the Trinity with the practice of his personal experience of asceticism and with the wide range of religious, social, and civic tasks that faced Russia in all its strata. In any case, Sergius was aware of the inexhaustibility of the religious and theological meaning of the Trinity, and of the exceptional importance of this dogma and this image. His intuition told him that there was a deep meaning here that transcended understanding. With his practical mind, he understood that from the small it is possible to form an idea of the large, from the part of the whole, while the meaning will be preserved within the given limits, and it is with this that he will have to work. It is possible that Sergius felt not only the idea of agreement in the Trinity, but also the reflection in this triune image of both the Divine Person and the human person. One of the most important Orthodox theologians of the 20th century wrote about the Trinity, rightly introducing it into the context of apophaticism (see above on the relationship between apophase and silence-hesychia):