Defining the concept of a trinitarian

I woke up this morning, and realized that there is a problem with how I’ve been defining the concept of a unitarian.  In this post, I will attempt a definition of the concept of a trinitarian, after reviewing what is required of a good definition. Next time, I’ll try to define the concept of a unitarian.

According to the textbook I have used for years in my critical thinking class, a good definition should:

  1. Include the genus and a differentia.
  2. Not be too broad or too narrow.
  3. State the essential attributes of the concept’s referents.
  4. Not be circular.
  5. Not use negative terms unnecessarily.
  6. Not use vague, obscure, or metaphorical language. (p. 44)

What is a trinitarian?

Definition 1: someone who believes in a triune god.

This fails criteria 2 and 6.

2 – The definition is too broad, that is, it lets things into the category which do not belong there. One might be a Hindu who believes in many gods, and one of these many gods is a triune god.  But this person would not be a trinitarian.

6 – The definition is obscure because of the term “triune” – which would seem to mean just, somehow or other triple or threefold.

In addressing 2, we should ask have to tighten up the definition.  It is not a trinitarian by definition a Christian?  I think not.  There have been scholars, admittedly, cranks, who have argued that ancient Jews including the authors of the Jewish Bible, were trinitarians.  This thesis, while patently false, is not false by definition.  So no, that is not the right way to define our term.

Yet we still need a definition which will exclude the sort of Hindu mentioned above.  I suggest that a Trinitarian is supposed to be by definition monotheistic.  Let us also specify the way in which the god is supposed to be triple or triune.

Definition 2: someone who believes that the one God in some sense consists of three “persons.”

The term “persons” has quotes around it to signify that this God in some sense contains three items called “persons.” Whether or not they are literally persons (i.e. selves) is left as an open question.  The definition must be vague in this way to encompass all the sorts of trinitarians out there.

But I think something has still been left out – the definition is still too broad.  Suppose that this one God was originally just the Father, and then sometime later, he created the Son and Spirit “within himself,” so that he now consisted of three persons.  Definition 2 would allow someone believing this to be a trinitarian.  But that is not correct.  This person does not believe that the three “persons” are “ontologically equal” – since the first is the creator of the second and the third.

As with “person” there is some vagueness in the term “ontologically equal” – and yet, I think this is correct – this is the idea actual trinitarians have in mind.

But the definition is still too broad.  Suppose a person thought that the one god consisted of Elvis, Bill Clinton, and Weird Al.  This person would not be a trinitarian, but they would satisfy the above definition.  So too would a Hindu monotheist who thought that the one God consisted of Brahma, Vishnu, and Shiva.  But this is not correct; trinitarianism has to do with the being or beings called by the names “Father,” “Son,” and “Holy Spirit” in the Christian tradition.  So let’s try again.

Definition 3: someone who believes that the one God in some sense consists of three ontologically equal “persons,” namely, the Father, the Son, and the Holy Spirit.

This definition is almost there.  But consider the kind of theory explored by Harriet Baber in our recent series here at trinities.  This was a type of serial modalism in which the one God has temporal parts, in sequence, Father (creation till Jesus), Son (Jesus’ earthly life), and Spirit (post-ascension).  These three would be ontologically equal, each being a temporal part of or stage of God.  But trinitarianism is supposed to be by definition incompatible with any sort of serial modalism.  So we must insert the word “eternally.”

Definition 4: someone who believes that the one God in some sense eternally consists of three ontologically equal “persons,” namely, the Father, the Son, and the Holy Spirit.

This definition seems correct to me.  I don’t see how it violates any of the six criteria for defining a concept.  What do you think?

Interestingly, I did not have to use any creedal language.  This was by design.  Some trinitarians happily embrace the term homoousion, but others take the view that such terms are theoretical constructions, and while they may have served well that Christians of the fourth century (or whenever), they may not be suited to our present-day world view.  Is this controversial?  Yes!  But I think those inclined towards the traditional language should nonetheless accept definition 3; they themselves count the people I’m talking about as trinitarians.

This is not a stipulative definition, that such as defining the concept of poverty as having a yearly income less than $15,000.  Rather, it is an attempt to specify the contours of a concept which is often employed.  A trinitarian is by definition supposed to not be any sort of (1) unitarian, (2) “Arian,” (3) Jew or Muslim, (4) serial modalist (“Sabellian”). I think the above does all this.

Finally, note that there is nothing polemical in this definition.  It should be accepted by Catholics, Muslims, Protestants, Jews, atheists, “biblical unitarians,” Jehovah’s Witnesses, Greek Orthodox believers – in short, anyone.  It does not stand as a shorthand for an argument; it is a neutral basis for rational discussion.

 Update: I think Definition 4 is still too vague, specifically the term “ontologically equal.” I think the idea is always that they are in some sense equal in their divinity. Now that term “divinity” is plenty vague, but I think it is vague in the right way; various Trinity theories understand it differently. So now I suggest:

Definition 5: someone who believes that the one God in some sense eternally consists of three equally divine “persons,” namely, the Father, the Son, and the Holy Spirit.

About Dale

Dale Tuggy is a Professor of Philosophy at SUNY Fredonia, where he teaches courses in analytic theology, philosophy of religion, religious studies, and the history of philosophy.

8 Responses to Defining the concept of a trinitarian

  1. Marg says:

    The definition may very well be accepted by all the groups you mention in your list, but I suspect Samuel Clarke would consider it too narrow. Judging from his book, Clarke considered himself to be a trinitarian, even though his writing does not fit your definition.

    However, I accept your right to define words as you intend to use them. So on this blog I am not a trinitarian, whatever I might call myself under my breath.

    By the way, you gave two assignments recently. One was completely out of my league, but somebody gave it a try. Will you be assessing the efforts of students who tried to do the assignments?

  2. Pingback: Defining the concept of a unitarian (Dale) » trinities

  3. Kenny says:

    I wonder if we should distinguish a broader term ‘trinitarian’ and a narrower term ‘orthodox trinitarian.’ If this distinction were made, definition 2 might be an adequate definition of ‘trinitarian,’ and 4 might be ok for ‘orthodox trinitarian,’ or we might want something even narrower than 4 for that.

    The reason I say this is that I’m inclined to regard the person who thinks the Father later created the Son and the Holy Spirit ‘within himself’ as a trinitarian, although of a highly heterodox variety. Note also that if ‘consists’ in definition 2 is given a metaphysically weighty reading, then it already rules out classical Sabellianism.

  4. Dale says:


    Thanks for this comment. You’ve put your finger on a tough issue – is a “trinitarian” *by definition* “orthodox” (i.e. really in compliance with the “ecumenical creeds” rightly understood).

    I think we have to say no… A trinitarian nearly always *wants* to be be and is trying to be orthodox, but does not always succeed. Also, it is often a matter of controversy whether or not someone is really in compliance. cf. Swinburne, Leftow.

  5. Dale says:


    That’s right – Clarke is surely a unitarian, and not a trinitarian. Just about all readers agree. Honestly, I think his desires to remain an Anglican minister, and to avoid controversy, caused him to bend language a bit (e.g. the title of his book).

    But to be fair, there’s an ambiguity in “the Trinity”. Does it mean a tri-personal God, or does it just refer to the Father, the Son, and the Holy Spirit, without any implication about how they are related? In this latter sense, every Christian has always been “trinitarian” – but that seems an abuse of language.

    I’ve complained about this sort of thing before:

  6. Pingback: How Trinity theories conflict with the New Testament (Dale) » trinities

  7. Marg says:

    I get your point about ambiguity.
    I can agree that Clarke was a unitarian. But at the same time, in your introduction to his book you speak of “Clarke’s trinitarian theology,” and you give a first rate summary of it. Then on the following page, you say,

    The best label for Clarke’s trinitarian theory is “subordinationist” …

    So although Clarke was a unitarian, his theory was trinitarian.
    That’s fair enough.

  8. Dale says:

    Marg, I think I need to correct that! I was obviously speaking loosely then, as many do, where any theory about the Father, Son, and Spirit is “trinitarian.” Thank you for pointing that out.

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