I originally wrote about this back in 2011, however, I felt it was worth revisiting from a more formal, logical perspective. Could it be the case that Christ could have chosen to sin, had he so desired, in his human incarnation? I do not think so, but a couple of syllogisms should be explained first.
11. God cannot sin.
22. Jesus is God.
33. Therefore, Jesus cannot sin.
44.
If one is a man, then he can sin.
55.
Jesus is a man.
66.
Therefore, Jesus can sin.
Obviously, (3) and (6) are contradictory, but both arguments
are logically valid. This means that at least one of the premises in one of the
arguments must be rejected (since both conclusions cannot be true at the same
time and in the same sense). The first thing we must understand for proper
Christology is that Jesus Christ is a divine person; He is the Second Person of
the Trinity. He was not two persons (one divine and one human), nor was he a
divine-human hybrid (as though he were half-God, half-man). He was one divine
person with two natures, a divine nature and a human nature.
So, let us examine (1). God cannot sin. This seems true
enough, but if we are to challenge it, we must say that if God can sin, this
implies, amongst other things, that he has moral duties to someone or
something, which is biblically and theologically false. God’s nature is the foundation
for moral values, so that he cannot deny himself logically. So that stays. What
about (2)? Orthodox views state that Jesus is God, but what does this mean?
This is what is called the “is of identity.” Jesus’ identity was God; he was a
divine person. So, obviously, the conclusion, Jesus cannot sin, follows
logically and inescapably.
But what about the other syllogism? Well, we must ask
ourselves, is the “is” in (4) and (5) of identity? I think it will be clear
that “is” in (4) is of identity; if one is a human person, then he can sin.
However, in (5), the “is” is called the “is of predication”; it is an attribute
of something. An example is to say that since Mr. Leporacci’s child was born,
he is a father. But Mr. Leporacci was not a father when he was seven years old.
Therefore, being a father is not Mr. Leporacci’s personal identity; being a father is predicated of Mr.
Leporacci now that his son is born. Similarly, Jesus is a divine person, and he
was not a human before the Incarnation; he took
on flesh, which necessarily implies there was a point he did not have it.
So being human is not the personal
identity of Christ, it is his predicative nature (fully what it means to be
human, of course!).
In that case, however, we can explain the second syllogism
as follows:
4*. If one is a human person, then he can sin.
5*. Jesus has a human nature.
6. Therefore, Jesus can sin.
However, now the conclusion (the “therefore” statement)
doesn’t follow from the new premises. Thus, Jesus cannot sin.
What about temptation? Is it really impossible to be tempted
if you cannot possibly fulfill it? Not at all. Suppose it’s your birthday, and
your spouse (or mom, for you unmarried people) makes you a great cake. You and
your family eat half of this cake, and the rest is placed in the refrigerator,
with the instructions not to touch it until the next day. You go to bed, and
wake up halfway through the night, craving more cake! You are extremely tempted
to get up and eat some, but you persevere. When you wake up, you go to the
fridge to see that the cake is all gone! It turns out that, shortly after you
went to sleep, your devious spouse/family ate all the rest before you even woke
to be tempted. You were truly tempted, but it wasn’t possible to act on that
temptation. This shows that it is at least possible for genuine temptation to
occur even when it is not possible to be fulfilled, and that means temptation
and ability are not identical.
Returning to the idea of (4-6), perhaps it can be salvaged
after all. Perhaps, instead of Jesus’ merely being a human in the predicative
sense, he was essentially a human. So, we can create a valid syllogism by
stating:
4*. If one is a human person, then he can sin.
5’. Jesus is a human person.
6. Therefore, Jesus can sin.
Now, one can see that (5’) is clearly different from (5*),
and both are in turn different from (5). (5’) contradicts orthodox Christology,
and beyond that, it seems plainly false. Biblically, the Word became flesh,
which means, roughly, that Jesus became a man. If that is the case, then his
being a man is a contingent fact about him. Contingent facts about persons are
not essential to their particular personhood; those would be necessary facts
(like Jesus’ being divine). So (5’) should be regarded as false. But there may
be another way to salvage the argument.
4’. For any one who is a person, if one has a human nature,
then he can sin.
5.*. Jesus has a human nature.
6. Therefore, Jesus can sin.
(4’) can really only be affirmed on either an inductive
basis or a fallacious basis. The latter basis is simply to assume what one is
trying to prove; one would assume that Jesus’ human nature means that he can
sin, and so formulate the premise that leads to that same conclusion. The
former basis would be to take a kind of survey of all of those with a human
nature, so that one sees that every instantiation of human nature has the
ability to sin, so Jesus does too.
There are a few problems with this. First, one does not take
an inductive survey to dictate metaphysical possibility. There could always be
an exception (namely, the one we are discussing, and to assume its
impossibility is to beg the question). Second, it assumes that Jesus human
nature does not differ in any way (when all sides should agree that it differs
in at least one major respect: the sin nature [here “nature” is used in two
different senses]). Finally, it does not take into account that sin is
something a person does, not a nature (William Lane Craig pointed out this
thought). In short, it seems impossible that the divine person Jesus Christ sinned (in the metaphysical sense).