Basil of Caesarea is one of the giants of the past. He was a pastor, a writer, and a theologian. His work On the Holy Spirit is still the best book you can read on the topic. And we have abundant access to his life through his extant letters. In Letter 38, for example, he writes to his brother Gregory of Nyssa (who would later preside over the Council of Constantinople), giving Gregory a crash course on the Trinity.
And it is quite simply the best short guide to the Trinity that I have ever read. I outline the argument below, so that you can participate in the crash course and become a better person (really). By learning more about God, you grow in your experience of God. And this is how God grows us from level of glory to another. Put more explicitly, by the Holy Spirit we gaze into the face of Christ so as to see the Father in it; by this knowledge, we grow from one level of glory to another.
Substance and Person
Basil worries that many who speak about the Trinity do not make a distinction between the words substance and person. And this has led to confusion because some claim that there is “‘one person in God'” or others divide God’s substance into three parts to match the number of persons (Father, Son, and Holy Spirit) (p. 84).
“Therefore,” writes Basil, “in order that you may not be led to embrace similar errors, I have written a short explanation of this as a reminder for you” (p. 84).
Natures Are Common, Persons Specify Certain Qualities of Natures
For Basil, the word “man” is a general term, but the name Peter specifies a person (84). So, “man” might bring to mind a common quality that all men have, but it doesn’t distinguish one man from another. So, one uses a “specific characterization” to refer to a specific person (p. 85). In other words, you use a name like “Peter or John” (p. 85).
After further explanation of common natures (humanity) and of specific characterizations that distinguish natures (e.g., names like Peter and John), Basil concludes:
This, therefore, is our explanation. That which is spoken of in the specific sense is signified by the word ‘person’ [hypóstasis]. For, because of the indefiniteness of the term, he who says ‘man’ has introduced through our hearing some vague idea, so that, although the nature is manifested by the name, that which subsists in the nature and is specifically designated by the name is not indicated. On the other hand, he who says ‘Paul’ has shown the subsistent nature of the object signified by the name. This, then, is the ‘person’ [hypóstasis]. It is not the indefinite notion of ‘substance’ [ousia], which creates no definite image because of the generality of its significance, but it is that which, through the specific qualities evident in it, restricts and defines in a certain object the general and indefinite, as is often done in many places in Scripture and especially in the story of Job. (pp. 85–86).
Here is what he is saying: If someone says “man” or “humanity,” one speaks about something common to all people, their nature. But when someone says, “Bob” or “Paul,” then one speaks of a person who subsists (participates in) the nature of man/humanity. Further, when someone says “Paul,” one also means “Paul” with all the specific qualities that make up Paul (a mustache, height, etc.).
The same holds true about God, although Basil warns us to be careful here because “the essence of the Father” is “above every concept” (pp. 86-87). So, God’s nature includes “‘Being uncreated and Incomprehensible'” (p. 87). And this will be true of the Father, Son, and Holy Spirit. But the persons of the Trinity have “individualizing marks” beyond what is a common to the nature of God; and these “qualities” distinguish the members of the Trinity from one another (p. 87).
How to Distinguish the Father, Son, and Holy Spirit
When it comes to the Trinity, the “substance is the common attribute, but the person is the specific quality of each” (p. 92). Basil goes on to clarify the specific qualities of each person of the Trinity, which distinguish the Father, Son, and the Holy Spirit from one another.
The Father is “without generation and without beginning” and he is “the principle of the principle of all things which exist” (p. 88). In other words, the Father is unbegotten (he is not begotten as the Son). He has no source because he is the principle of the principle. So, “from the Father is the Son” (p. 88).
And “the Holy Spirit is always inseparably associated” with the Son (p. 88). “In fact,” writes Basil, “it is not possible for one not previously enlightened by the Spirit to arrive at a conception of the Son” (p. 88). And the Holy Spirit’s existence is “dependent on the Father as a principle, from whom He also proceeds” (p. 88).
To summarize, the Father is unbegotten and the source of all things. The Son is “from the Father” and therefore begotten and stems from the Father. The Spirit always associates with the Son and his existence in the Father.
Basil then continues to clarify how the Son and Father are distinguished from one another, writing:
Now, the Son, who through Himself and with Himself makes known the Spirit which proceeds from the father and who alone shines forth as the Only-begotten from the Unbegotten Light, shares in common with the Father or with the Holy Spirit none of the peculiar marks by which the Son is known, but He alone is recognized by the marks just mentioned. Furthermore, the supreme God alone has a certain special mark of His person by which He is known, namely, that He is the Father and subsists from no other principle; and, again, through this mark He Himself is also individually recognized. (p. 88)
The Son is the Only-begotten who makes known the Spirit. The Father is Unbegotten and the principle of all. As for the Spirit, Basil mentioned prior to this that “He is made known after the Son and with the Son and that He subsists from the Father” (p. 88).
So, these are the distinguishing marks of the Trinity.
- For the Father, he is Father, Unbegotten, and the principle of all;
- For the Son, he is the Son, the Only-begotten of the Father, the revealer of the Spirit, and “from the Father”;
- For the Spirit, he is the Spirit, associates with the Son, is known after the Son, proceeds from the Father, and has his existence dependent on the Father, the principle.
The Common Nature of God
The Father, Son, and Holy Spirit share in infinity, incomprehensibly, un-createdness, “being circumscribed within no space,” and the rest (p. 89). For the Trinity, there is a “constant and uninterrupted sharing in them” (p. 89). The commonality allows no division among the Trinity.
According to Basil, “there is found in them a certain inexpressible and incomprehensible union and distinction, since neither the difference of the persons breaks the continuity of the nature, nor the common attribute of substance dissolves the individual character of their distinctive marks” (p. 90).
While the Son is identical to the Father, he is nevertheless “something else” (p. 95). He is the image of the Father and so identical and yet distinguished by being the image of the Father (p. 95).
All that is in God is common to God, even though the persons of the Trinity possess distinguishing marks. “For,” Basil writes, “all the attributes of the Father are beheld in the Son, and all the attributes of the Son belong also to the Father, since both the whole Son remains in the Father and has the whole Father in Himself” (p. 96).
He continues, “Therefore, the person of the Son becomes, as it were, the form and face of the knowledge of the Father, and the person of the Father is known in the form of the Son, although the individuality observed in them remains for the clear distinction of their persons” (p. 96).
In summary, Basil maintains that the Trinity fully shares the nature of God without division. The marks that distinguish the Trinity merely specify qualities to distinguish the Father, Son, and Holy Spirit. They are not attributes; they are not natures.
Basil’s short letter to his little brother sketches out what has become (and already was) the classical doctrine of the Trinity. Gregory of Nyssa would preside over the Council of Constantinople in 381, ensuring that the orthodox confession of the Trinity would persist for the ages.
It’s not as if Basil invented this language to talk about God. Christians already in the second century (the 100s) spoke about God as a Trinity. But it took a couple hundred years of thinking together to learn how to say it just right.
So let’s press on in our knowledge of God by relearning what our mothers and fathers of the Faith had already figured out: God is one being in three persons who is distinguished by relations of origin (e.g., the Son is from the Father).
Let’s press on despite the difficulty of learning Trinitarian syntax. For eternal life is knowing God (John 17:3). So, it’s worth the effort. It’s worth putting in the time, lest you fall into error and miss out on eternal life.