How Should Catholics Understand Romans 9?

In the comments on Friday's post, a Calvinist convert to Catholicism asked what to make of Romans 9:18-21, which sound like Paul's saying that God made some people for Heaven, and some people for Hell:

You will say to me then, "Why does he still find fault? For who can resist his will?" But who are you, a man, to answer back to God? Will what is molded say to its molder, "Why have you made me thus?"  Has the potter no right over the clay, to make out of the same lump one vessel for beauty and another for menial use?

I would suggest that this passage needs to be read in the context of Paul's fuller argument (which runs from Chapter 9 to Chapter 11 of the Epistle), and I'd make these points:

(1) Yes, that part of Romans 9 really does sound like St. Paul is saying that God mercifully saves some, and damns the rest.  After all, in v. 18, he says, “So then he has mercy upon whomever he wills, and he hardens the heart of whomever he wills.” He then proceeds with the three verses that the commenter cited to, in which Paul rhetorically asks and answers the question, “Why does he still find fault? For who can resist his will?”

But here’s the thing. We know that, despite how it may sound, St. Paul isn’t saying that those whose hearts are hardened are eternally damned. And we know this because St. Paul explicitly denies that this is what he’s saying, when he continues this line of argumentation two chapters later.

In Romans 11:7, he says that “Israel failed to obtain what it sought. The elect obtained it, but the rest were hardened.” Then he says of those who have been hardened, “So I ask, have they stumbled so as to fall? By no means!” (Rom. 11:12).  On the contrary, Paul explains that part of his ministry to the Gentiles is “to make my fellow Jews jealous, and thus save some of them” (Rom. 11:14). And thus, “a hardening has come upon part of Israel, until the full number of the Gentiles come in, and so all Israel will be saved” (Rom. 11:25-26).

Now, this chapter in particular, with branches being cut off from Christ, or ingrafted on to Him, quite plainly repudiates any notion of “once saved, always saved.” I’d go so far as to say that this makes sense only if election is conditional – specifically, if it is conditioned on faith, as Paul explicitly says it is in Romans 9:30-31 and Rom. 11:20-21.

(2) The term “elect” simply means “chosen,” so the obvious question is: chosen to what? Are we talking about election to graces and blessings (like having five talents, instead of one), election to participation in the life of the visible Church, or election to eternal life? Protestants tend to assume that “election” is always meant in this third sense, but I’ve never seen a good explanation for this belief. In fact, verses like Romans 11:28 seem to confound that sort of reading.  And if the election Paul is speaking of is to eternal life, then the answer to his rhetorical question in Rom. 11:12 would be “yes,” since he's defined the hardened to be those who aren't elect (Rom. 11:7).

On the other hand, if Paul is speaking of election in either of the first two senses - that of blessings and curses, or particularly, of being part of the visible chosen people - Romans 9 and 11 make a lot more sense.  After all, the famous line, “Jacob I loved, but Esau I hated,” that Paul cites to in Rom. 9:13 wasn't originally about eternal salvation at all.  It was about the way that God had preserved and protected the Israelites, while allowing the country of the Edomites (the descendants of Esau) to be turned into a wasteland (Malachi 1:2-5).    There's no reference in the passage to the salvation of Jacob, Esau, the Israelites, or the Edomites... unless one presupposes that the prosperous are saved, and the desolate are damned.

(3) Finally, St. Paul explicitly denies that God shows any favoritism, as regards salvation, in Romans 2:4-11:

“Or do you presume upon the riches of his kindness and forbearance and patience? Do you not know that God's kindness is meant to lead you to repentance? But by your hard and impenitent heart you are storing up wrath for yourself on the day of wrath when God's righteous judgment will be revealed. 

For he will render to every man according to his works: to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life; but for those who are factious and do not obey the truth, but obey wickedness, there will be wrath and fury. 

There will be tribulation and distress for every human being who does evil, the Jew first and also the Greek, but glory and honor and peace for every one who does good, the Jew first and also the Greek. For God shows no partiality.”

Ironically, despite Paul's warning here not to “presume upon the riches of his kindness and forbearance and patience,” Calvinists use this Epistle to justify the idea that once you're saved, you're always saved.  And despite Paul's point that “God shows no partiality” (which is literally the central argument of the Epistle, since Paul's answering the idea that God arbitrarily divided the world into two immutable groups: Jews and Gentiles), Calvinists use this Epistle to justify the idea that God shows partiality, and divided the world into two immutable groups: the elect and reprobate.

The only thing I would add to this is Fr. William Most's commentary of the massa damnata interpretation of this passage of Romans 9:

Fr. William Most

All exegetes today reject this interpretation. As Huby points out, [Cf. Joseph Huby, SJ, Saint Paul, Epitre aux Romains, Traduction et Commentaire, Verbum Salutis X, Beauchesne, Paris, 1957, p. 349.] it is altogether arbitrary to say that the "clay" in v. 21 stands for the human race, corrupted by original sin, because in the whole of chapter 9 there is not even a remote allusion to original sin. Lagrange makes a keen observation [M.J. Lagrange, OP, Saint Paul, Epitre aux Romains, Gabalda, Paris, 1931, p. 238.]: "At least the potter does not blame the vessels which he has made for ignoble uses." Hence, if God really had made certain men for ignoble roles, He should not blame and condemn these men for being such. 

Actually, St. Paul was only making a comparison, or, as Lagrange says, [Ibid.] "a simple parable." St. Paul wishes to teach that God has the right to assign men to various places in the external order of this world-which is quite different and distinct from the internal order of eternal salvation or ruin! That is, God makes some to be kings, others physicians, others laborers, etc. And similarly, He brings some into the Church in the full sense, and not others. But these assignments by no means fix the eternal lot of a man. Later in this chapter we shall examine what relation does exist between a man's eternal lot and his place in the external order of this world.

So in short, reading Paul to be talking about eternal life and eternal death in Romans 9:18-21 would not just contradict Catholic theology.  It contradicts the rest of Paul's line of argumentation in Romans itself.  It's a much stronger reading to view Paul as talking about (a) the blessing and curses of ordinary life [like giving one person five talents, and another one], and/or (b) participation in the life of the visible Church [which fits the general theme of Romans].