Blog 53: 2.5.4 - 2.5.8
The next argument in favor of free will that Calvin refutes concerns exhortations or commands. To put the matter differently: What good is any moral instruction if we are not free? In my reading of Pelagius this concern seems to drive him the most in his debate with Augustine. How can I hold people accountable? How can I expect anything of them if they are not free? These questions by Pelagius brought about Augustine's On Rebuke and Grace and On the Spirit and the Letter. These questions bring out in Calvin some rather helpful ideas on obedience, what we might call sanctification or spiritual formation.
One of the first things Calvin points us to is our moral inability, which in turn points us to Christ. John 15:5 has it fairly direct: "Apart from me you can do nothing." Paul chimes in too, at 1 Corinthians 3:3, 3:7, and 16:14, Romans 9:16, and also at Philippians 4:13 (see 2.4.4).
Next, Calvin examines the nature and purpose of exhortations. They serve a confirming purpose on the reprobate, "to press them with the witness of conscience" (2.5.5). They serve a convicting and chastising purpose on the elect. In this latter case, we are drawn away from ourselves and to God's graciousness and to Christ's work on the cross. Calvin turns to his friend Augustine, "Faith achieves what the law commands" (cited in 2.5.7).
A p.s. for the historical sleuths: Calvin's reference to "stocks and stones" and "rocks or stumps" (2.5.7) shows up in the Canons of Dort as "stocks and blocks."