THE TRADITIONAL SYMBOL OF THE TRINITY

The equilateral triangle is commonly proposed as a symbol expressive of this mystery, and the symbol expresses more than is sometimes thought. It very tangibly expresses an outline of the mystery with respect to the distinction between the persons and those things that flow from it.

(a) The three angles are really distinct from each other although they are not really distinct from the area of the triangle, which is numerically the same for all three angles. Thus the three divine persons are really distinct from each other but not from the divine essence, which is numerically the same in all three persons. Further, the three angles are really distinguished from each other by opposite relations but not from the area to which they are in no way opposed; so also it is with the three divine persons.

(b) The three angles are equal and, as it were, consubstantial because they are constituted by the same surface which is no greater in the three than it is in one. Thus there is one surface in three distinct angles but not distinguished into three angles.

(c) Each angle renders the surface incommunicable in its own way, nevertheless when the first angle is formed it does not cause the surface of the other angles although it communicates its surface to the second angle, and through the second angle to the third. Thus the first angle, although not really distinct from its surface, communicates that surface without communicating itself. In the Trinity the Father communicates the divine nature but not Himself; likewise the Son with respect to the Holy Ghost.

(d) Lastly, even though the angles are equal, there is among them an order of origin without causality: the first angle once formed becomes the principle of the second, and both of these are the principle of the third. At the same time the second and third are not caused by the first because their surfaces are not caused, but it is the surface of the first which is communicated to them. This analogy will become clearer when the principal definitions of the Church on the Trinity are reduced to the following propositions, which are often written around an equilateral triangle as below.

The Father is God, the Son is God, the Holy Ghost is God, and yet the Father is not the Son, because He does not generate Himself; nor is the Father the Holy Ghost, or the Son the Holy Ghost, because those who spirate are distinguished from that which is spirated as he who generates is distinguished from that which is generated. In the statement of this mystery we see the profound meaning of the word "is" and of the negation "is not." As St. Thomas says:[46] In every affirmative proposition about some reality the word "is" expresses the real identity of the subject and predicate. Here it expresses the real identity of the three divine persons with the divine essence, and the negation "is not" expresses the real distinction of the persons from each other. In this statement of the mystery the apparent contradiction is explained, that contradiction arising if God would be said to be one and three under the same aspects, e. g., nature.

In the Catholic Catechism, written by Cardinal Gasparri, this mystery is defined as:

(a) "God is one in the unity of nature in three really distinct persons, the Father, the Son, and the Holy Ghost, who constitute the Holy Trinity."[47] Thus the Father is the Godhead but He is not the Trinity.

(b) How are the Father, the Son, and the Holy Ghost distinguished from one another?

Answer. By the opposite relations of the persons, inasmuch as the Father generates the Son, and the Holy Ghost proceeds from both. (The Father does not generate Himself.)

(c) How are the three divine persons one God?

A. Because they are consubstantial, that is, they have one and the same divine nature and therefore the same attributes or perfections and operations "ad extra." (The operations "ad extra" proceed from omnipotence, which is common to the three persons.)

(d) Is not power usually attributed to the Father, wisdom to the Son, and goodness to the Holy Ghost in the Scriptures?

A. Although all the attributes of divinity are common to the three divine persons, the Scriptures usually attribute power to the Father because He is the font of origin, wisdom to the Son because He is the word of the Father, and goodness and holiness to the Holy Ghost because He is the love of the other two.[48]

We will spend no more time in the simple statement of this mystery; the explanation of the terms nature, person, and so on will be found in St. Thomas' articles.