I’ve read a good number of pages on the nature of the human will recently, and little has been as helpful on free will as Charle’s Hodge’s brief summary in his Systematic Theology.

He speaks of three views of the will: necessity, contingency, and certainty. I won’t go into the first and third (click here to read the whole section for yourself; it’s about eight relatively small pages), but here is his excellent development of the second view of the will. This is not Hodge’s view, but it a view held by many evangelicals today. (I added the bullet points.)

The doctrine of contingency…has been held under different names and variously modified.

• Sometimes it is called the liberty of indifference; by which is meant, that the will, at the moment of decision, is self-poised among conflicting motives, and decides one way or the other, not because of the greater influence of one motive over others, but because it is indifferent or undetermined, able to act in accordance with the weaker against the stronger motive, or even without any motive at all.
• Sometimes this doctrine is expressed by the phrase, self-determining power of the will. By this it is intended to deny that the will is determined by motives, and to affirm that the reason of its decisions is to be sought in itself. It is a cause and not an effect, and therefore requires nothing out of itself to account for its acts.
• Sometimes this doctrine is called the power of contrary choice; that is, that in every volition there is and must be power to the contrary. Even supposing all antecedents external and internal to have been precisely the same, the decision might have been the reverse of what it actually was.

Contingence is therefore necessary to liberty. This is the essential idea of this theory in all its forms. A contingent event is one which may or may not happen. Contingence, therefore, is opposed not merely to necessity, but also to certainty. If a man may act in opposition to all motives, external and internal, and in despite of all influence which can be exerted on him, short of destroying his liberty, then it must forever remain uncertain how he will act. The advocates of this theory of liberty, therefore, maintain, that the will is independent of reason, of feeling, and of God. There is no middle ground, they say, between contingency (i. e., uncertainty), and fatalism; between the independence of the will and of the agent, and the denial of all free agency. (Vol. 2, pp. 282-283)

Let’s all admit that the common Christian case for free will makes a certain easy sense: God gave Adam free will because it is a necessary ingredient in true love for God and others. But (and this is where the view, in my opinion, starts to make less easy sense) God took a risk: along with free will came the possibility that Adam would sin. Free will today has the same function, enabling people to truly obey God—and to rightly be blamed when they don’t.

But those inside and outside Christianity who have thought hard about free will have tended to take one of the positions Hodge outlines above, and contemporary Christians who believe in “free will” need to wrestle with what taking one of these positions really means for their theology. They also need to wrestle with Paul’s very direct answer to the question of free will, found in Romans 9:19–20.