An Intro to the Philosophy of Religion, Ch. 3

The first two chapters have broadly examined theistic belief, but Murray and Rea will now discuss the Christian doctrines of the Trinity and the Incarnation.  Can they be established philosophically, apart from scripture?[1]  A brief discussion of  heresies proceeds into some philosophical critique of the orthodox (officially recognized) doctrines. Orthodox practitioners may disagree with this conclusion :

"So if it turns out that Christian doctrine as interpreted by those creeds and councils is incoherent, then, at the very least, large segments of Christendom will be forced to revise their religious views and also, perhaps, to revise their views about the authority and reliability of the relevant creeds and councils." (emphasis original)

The Trinity

Monotheism holds that there is one God.  Unitarianism holds that God is one person, and Trinitarianism holds that God is three persons (Father, Son, and Holy Spirit).  Three heresies regarding this doctrine are as follows:

1. Modalism - Denying the distinction of three persons.  God manifests himself in different ways like Superman and Clark Kent
2. Polytheism - Denying the oneness of God
3. Subordinationism -  Denying the divinity of all three persons.  Christ is not fully divine, or the Holy Spirit is not fully divine.  

The authors critically examine some analogies to see if they partially/fully illuminate the orthodox view.

The social analogy

Abraham, Sarah, and Isaac are one family.  Those who understand the Trinity this way are Social Trinitarians.  The Father, Son, and Holy Spirit are one (monotheism) in two senses: (a) they are members of the single Godhead, and (b) they each fully possess the divine nature.  Thus, to say the Father is God is to ascribe to the Father the property or characteristic of being divine.  This analogy suggests tritheism more than others.

Psychological analogies

This analogy compares God to a human with multiple-personality disorder.  Along these lines, some suggest that the brain has two distinct spheres of consciousness--a theory derived from commissurotonomy (treating epilepsy by cutting the bundle of nerves that connect the two brain hemispheres).  This analogy seems incomplete, but it does offer an ostensible conception of tri-personhood.

The statute-lump analogy

Two things can similar relative to one kind of thing, but distinct relative to another.  "x is an F, y is and F, x is a G, y is a G, x is the same F as Y, but x is not the same G as y."  It looks to be a Leibnizian way of saying that there is one God (all three are indiscernible with respect to being) and yet there are three persons (all three are not indiscernible with respect to personhood).  Consider Rodin's statue The Thinker.  "It can be truly described as a lump of bronze and as a statute."   The lump of bronze shares the same matter in common with The Thinker, but clearly the two are distinct.  We could melt down the statute and still be left with a lump of bronze, thus implying distinction.[2]

Arguments for the Trinity

Philosophers can't seem to cite a precise irrefutable problem, but what arguments support this doctrine?  First, those with prior commitment to scriptural inspiration will want to examine exegetical arguments.  Their point of concern is what the Bible actually says.  But what of the philosophical case?  Richard Swinburne has offered an a priori argument for the doctrine of the Trinity; here is my (rough) reconstruction:

Let PL be perfect love, and PLB be a perfectly loving being.  Assume a PLB necessarily has PL.

1) God is a PLB

2) PL requires a beloved (second) person

3) PL requires a (third) person whom the lover and beloved can cooperate together in loving

3) God was free not to create anything.  Thus possibly, no created persons exist for him to love

4) Therefore, if a PLB exists then there must be three uncreated persons (and anything more wouldn't be parsimonious)

In conjunction with arguments for monotheism, this implies that three divine persons are entailed by PLB.  Taken on its own, it merely implies tritheism.  It certainly succeeds in capturing a very powerful intuition that we have about love.  Some may find this argument less compelling, such as those that deny God's intrinsic loving nature.  Perhaps God might not have been loving, had he freely chosen not to create anything at all.  In general, the debates over the Trinity involve what I like to call "above the arch" and "below the arch" argumentation.  We are either asking, "What is God like transcendentally?" or "What is God like immanently?"  Many believe that God is only an immanent tri-person, and thus this is only how God relates to mankind (in spacetime).  Others reject Swinburne's argument, doubting that our intuitions about love can ground conclusions about God's nature.

Incarnation

How can it be that Christians worship Jesus, when the the first commandment clearly compels them to only worship God?  The answer: they believe Jesus is God incarnate.  "But what could possibly lead someone rationally to think that a thirty-something-year-old Palestinian man, born to a local carpenter and raised in a town of little import, was none other than the Lord of the Cosmos in human flesh?"

Lord-Liar-Lunatic

The Lord-Liar-Lunatic argument was developed in the seventeenth century by Blaise Pascal and then popularized in the late twentieth century by C.S. Lewis.  The argument offers three competing theses about Jesus: he was divine as he claimed, he was an incredibly deceitful liar, or he was a lunatic.  Notice that this argument does not include the popular position that Jesus was "merely a good teacher"...for what kind of good teacher would falsely claim to be God?  This argument is built on the assumption that the Biblical accounts of Jesus' ministry (miracles, sermons, dealings with the Pharisees) are somewhat reliable--a proposition that requires significant defense.  A host of historical theories about Jesus' "real ministry" have been developed against a set of different assumptions: particularly, the assumption that miracles are not possible, or at least historically unacceptable as an explanation for anything.  So, the third leg of L-L-L stands or falls upon our Biblio-historical position.  Some resist the thesis that Jesus was insane, pointing out that other great rulers, such as Julius Caesar or Akhenaton, thought themselves divine too.  But we would hesitate to say that they were insane (socially conditioned?).  Unless one appreciates the stark contrast between monotheistic conceptions of God and other Roman or Egyptian conceptions, this resistance might seem plausible. But Jesus was not crucified because he claimed to be a powerful superhuman, rather he was crucified by his own Jewish community because he claimed to be Yahweh.  Other philosophers have resisted the insanity charges on epistemological grounds: arguing that it is possible to have sane justified beliefs about your own divinity.[3]

The orthodox doctrine and the heresies

The doctrine of Incarnation describes Jesus as one person with two natures (fully human and fully divine).  Some heresies are listed: Arianism (Jesus was not fully divine), Ebionism (Jesus was just a man), Docetism (Jesus was not fully human), Nestorianism (Jesus was not one person), Monophysitism (Jesus didn't have two natures, only one divine nature), Appolinarianism (Jesus lacked a human soul), and Monothelitism (Jesus had only one will).  Might I note: a closer study of these heresies reveals more subtlety and nuance.  All but the last heresy was specifically condemned at the Council of Chalcedon in 451 AD.

Problems
The second person of the Trinity became incarnate, rendering two separate wills (divine and human), yet still only one divine person; how can this be held consistently with philosophical understandings of persons and agents?  If Jesus the man (body/soul/will) was incarnated by God the Son (will), would there not be two separate persons accompanying the two wills?  And what of scriptures that imply Jesus grew in wisdom (Luke 2:52), or reporting his own lack of knowledge about the last day (Matthew)?  And how could Jesus be meaningfully tempted to sin if he was God incarnate (impeccability)?  There are some serious prima facie problems with this position that need to be worked out.

Responses
Three-Part Christology says that Jesus Christ consisted of a body, soul, and the Son (second person of the Trinity); however, this is not two persons.  Regarding the apparent lack of Jesus' omniscience, the doctrine of kenosis attempts to align with a Bible verse.  "Although He existed in the form of God, did not regard equality with God a thing to be grasped, but emptied Himself, taking the form of a bond-servant, [and] being made in the likeness of men."  Kenotic theories suppose that Jesus either abandoned omniscience, or else at least gave the appearance of not having it.  Thomas Morris has a "Two Minds" view of the Incarnation, in which "the divine mind of God the Son contained, but was not contained by, his earthly mind, or range of consciousness."  The earthly conscience didn't have fully access to the divine mind.[4]

Conclusion
A variety of problems and potential solutions confront the Christian who would delve deeply into the doctrines of the Trinity and Incarnation.  Sometimes, merely steering clear of shipwreck on the "rocks of incoherence" is sufficient.

1 James White's The Forgotten Trinity gives excellent attention to detail regarding the Biblical basis for this doctrine.

2 See Peter van Inwagen's essay, “Three Persons in One Being: On Attempts to Show That the Doctrine of the Trinity is Self-Contradictory”, in The Trinity: East/West Dialogue, M. Y. Stewart (ed.), Boston: Kluwer, pp. 83–97.

3 Daniel Howard-Snyder, "Was Jesus Mad, Bad, or God?...or Merely Mistaken?"  Faith and Philosophy 21 (2004), pp. 456-79.
4. Thomas Morris, Our Idea of God (Notre Dame, IN: University of Notre Dame Press, 1991), p. 169.