Nelson Pike on Thomas Aquinas and an Omnipotent Being’s Ability to do Evil

In his paper 'Omnipotence And God's Ability To Sin', Nelson Pike criticises Thomas Aquinas on his defence of how God’s impossibility to do evil can be reconciled with His omnipotence. Quoted below is Thomas' defence.

To sin is to fall short of a perfect action; hence to be able to sin is to be able to fall short in action, which is repugnant to omnipotence. Therefore, it is that God cannot sin, because of his omnipotence. Now, it is true that the philosopher says that God can deliberately do what is evil. But this must understood either on condition, the antecedent of which is impossible - as, for instance, if we were to say that God can do evil things if He will. For there is no reason why a conditional propositional should not be true, though both the antecedent and the consequent are impossible; as if one were to say: if a man is an ass, he has four feet. (ST 1.25.3)

As we can see, Thomas argues that we can make sense of how we can say that God is incapable of evil and yet omnipotent by claiming that if God were to will to do an evil action, He could do it, even if the antecedent and the consequent are both false. 

Pike has a problem with this. He attempts to show that Thomas’ defence is problematic by demonstrating through the use of similar statements that Thomas’ conditional statement is insufficient to defend God’s omnipotence and inability to do evil. Pike asks us to consider the following two statements:

(1) Jones has an ace in his hand if he wants to play it. 

and,

(2) Jones can wiggle his ear if he wants to.

Pike notes that while on the surface these statements seem like conditionals, they are in fact not, for the items mentioned in the if… clauses do not contain the item contained in the rest of the statements. If Jones has an ace in his hand, he has an ace in his hand whether or not he wants to play it. Similarly, Jones has the ability to wiggle his ear whether or not he wants to. The question of whether Jones wants to wiggle his ear does not determine whether or not he has the ability. So, the if clause here does not serve as a conditional on whether he has the ability or not; rather, it is there to indicate the indeterminacy of whether or not he will exercise this power. 

However, in such statements the relation between truth values of the antecedent and the consequent is such that if the antecedent is false, so is the consequent; so, if Jones does not have the ability to wiggle his ear, then he cannot wiggle his ear if he wants to. Pike maintains that Thomas’s ‘conditional’ statement is the same sort of statement as (1) and (2); this means that if the antecedent is false, so is the consequent, entailing that if it is false that ‘God can do evil things’ it is also false that ‘God can do evil things if He wants to’. Given Thomas does argue that God cannot do evil, he must maintain that He cannot do it even if He wants to. 

I think that Pike has made an error. Pike is quite right that in statements such as ‘Jones can wiggle his ear if he wants to’ and ‘Jones has an ace in his hand if he wants to play it’, the consequent is dependent upon the antecedent and does not determine it. But is this the same with the claim that God can do evil if He wants to? No. This is because in Thomas’ thought God’s ability to do evil is dependent upon whether he wills it; and this is clear from the preceding claim in Thomas’ quote that to sin is to fall short of a perfect action. This is why doing evil is a hinderance to omnipotence. 

Earlier in his paper, Pike dismisses the idea that to do evil is to fall short of a perfect action. Pike argues that we need to distinguish between one being morally weak and one being weak in power; he says that he sees no reason why a being who could bring about any consistent state of affairs could not be morally weak: to quote, ‘I see no conceptual difficulty in the idea of a diabolical omnipotent being. Creative-power and moral strength are readily discernible concepts’.

What Pike has failed to acknowledge is how Thomas’ statement here relates to his wider metaphysics and the other divine attributes. For Thomas held that we all aim for what is good and that we sin by failing to properly realise what is really good. Hence, the drug abuser thinks that stealing and taking drugs will be good for him even if he thinks that it is morally wrong; he deicides that it will be better to do morally wrong (he will usually justify his wrongdoing to himself) and get the drugs than not to steal the drugs. Yet, as we all know, taking drugs will not be good for the drug abuser. God, however, as an omnipotent being is also omniscient. God will therefore know the good to aim for. And, for Thomas as well as other classical theists, this can only be God Himself. God is His own end. And given that the ends and highest ideals of all created things exists in the mind of God, this will lead God to be making these things His ends too, in aiming for Himself. And this is why God is necessarily good, as demonstrated here.

Now, God could only fail to properly aim at Himself if He was either (1) not omniscient, and hence not omnipotent, or (2) not omnipotent and therefore lacked the power to do it. This is why Thomas says ‘Therefore, it is that God cannot sin, because of His omnipotence.’

Since it is God's will towards himself that prohibits Him from committing evil, it is true that ‘God can do evil things if He were to will it’. That is to say that God would have the power and ability to do it if He willed it - something that Pike actually attempts to defend later on, albeit differently to how we have done so here. But unlike humans who can err in what they think is good because of lack of omniscience, God cannot do this and therefore will only will what is good, although He would have the power to will otherwise were He to do so.