The reader is offered the 2nd (revised) edition of the complete translation of the treatise "On the Trinity" by the outstanding Christian thinker St. Aurelius Augustine (Blessed) (354-430 from R.H.). This work in its meaning is on a par with such works as "Confession" and "On the City of God," and is devoted to the systematic a statement of doctrine in which Augustine saw the basis of Christian doctrine. Starting with the exegetics of the texts of Holy Scripture, Augustine defends the dogma of trinity from a philosophical point of view, using analogies with the natural world and especially with the forms of activity of the human mind.