I have recently finished reading the book by Michael Horton entitled God of promise: Introducing Covenantal Theology, which I think is a good primer on Covenant Theology, being much more readable and biblical than O. Palmer Robertson's The Christ of the Covenants. In the process of reading the book, I came across an interesting paragraph quoting John Calvin on the Covenant of Works. Since I have Calvin's Institutes with me, albeit by a different translator and publishing, I can check the two cross-references for the quotes in context. What I have found has indeed confirmed Horton's points, and pours cold water on those who claim to be Reformed in the tradition of John Calvin yet deny the Covenant of Works in any form.
On pages 87-88, discussing the biblical proofs for the Covenant of Works,
With the covenant of redemption, in which the Son is made the mediator of the elect, and the covenant of creation (or works), under which terms the Son, acting as mediator and second Adam, won eternal life under the law, "earning eternal life has forever been taken out of his [man's] hands.... On this point, the entire Reformation, both Lutheran and Calvinist, took exception to Rome, which failed to appreciate this fundamental truth." In other words, the covenant of redemption contrasts the salvation of the elect to Christ's meritorious fulfillment of personal obedience to God's law.
Although this view of things is hardly representative of a fully developed federal theology, Calvin does assert the main features of the covenant of creation. In a number of places, Calvin refers to Christ's having "merited' salvation for his people by his obedience, once more emphasizing the satisfaction of law as a necessary prerequisite for everlasting life.
Footnote 21 reads thus:
21. John Calvin, Institutes of the Christian Religion, ed. John T. McNeill, trans. Ford Lewis Battles (Philadelphia: Westminster, 1960), 1.15.8: "In this integrity man by free will had the power, if he so willed, to attain eternal life. Here it would be out of place to raise the question of God's secret predestination because our present subject is not what can happen or not, but what man's nature was like. Therefore Adam could have stood if he wished, seeing that he fell solely by his own will.... Yet his choice of good and evil was free, and not that alone, but the highest rectitude was in his mind and will, and all the organic parts were rightly composed to obedience, until in destroying himself he corrupted his own blessings. Hence the great obscurity faced by the philosophers, for they were seeking in a ruin for a building, and in scattered fragments for a well-knit structure. They held this principle, that man would not be a rational animal unless he possessed free choice of good and evil; also it entered their minds that the distinction between virtues and vices would be obliterated if man did not order his life by his own planning. Well reasoned so far — if there had been no change in man. But since this was hidden from them, it is no wonder they mix up heaven and earth!"
Here is the text from the same section in the translation by Henry Beveridge (Wm. B. Eerdmans: Grand Rapids, MI, USA, 1989)
... In this upright state, man possessed freedom of will, by which, if he chose, he was able to obtain eternal life. It were here unseasonable to introduce the question concerning the secret predestination of God, because we are not considering what might or might not happen, but what the nature of man truly was. Adam, therefore, might have stood if he chose, since it was only by his own will that he fell; [but it was, because his will was pliable in either direction, and he has not received constancy to persevere, that he so easily fell.] Still he has a free choice of good and evil, and not merely so, but in the mind and will there was the highest rectitude, and all the organic parts were duly framed to obedience, until man corrupted its god properties, and destroyed himself. Hence the great darkness of philosophers who have looked for a complete building in a ruin, and fit arrangement in disorder. The principle they set out with was, that man could not be a rational animal unless he has a free choice of good and evil. They also imagined that the distinction between virtue and vice was destroyed, if man did not of his own free counsel arrange his life. So far well, had there been no change in man. This being unknown to them, it is not surprising that they throw everything into confusion.
(Text in square brackets comprise the section marked out by ellipses in the previous quote)
Footnote 22 reads thus:
22. Ibid. "By his obedience, however, Christ truly acquired and merited grace for us with his Father. Many passages of Scripture surely and firmly attest this. I take it commonplace that if Christ made satisfaction for sins, if he paid the penalty owed to us, if he appeased God by his own obedience ... then he acquired salvation for us by his righteousness, which is tantamount to deserving it... Hence it is absurd to set Christ's merit against God's mercy" (2.17.1,3, emphasis added).
And here is the Henry Beveridge's version of the quoted section:
That Christ by his obedience, truly purchased and merited grace for us with the Father, is accurately inferred from several passages of Scripture. I take it for granted, that if Christ satisfied for our sins, if he paid the penalty due by us, if he appeased God by his obedience; [in fine, if he suffered the just for the unjust], salvation was obtained to us by his righteousness; which is just equivalent to meriting. ... Hence the merit of Christ is inconsiderately opposed to the mercy of God.
(Text in square brackets comprise the section marked out by ellipses in the previous quote)
As it can be seen, John Calvin teaches that prelapsarian man — Adam, by nature have a free will to choose good or evil. The focus is that it is such by nature, although in fact it is not independent of the environment and most definitely of God. But because of his nature, therefore in terms of volition, Man is neutral with regards to sin and temptation (ie able to sin and able not to sin), although he is ontologically righteous.
The second footnote show here completes the seed form of the Covenant of Works in Calvin's theology. Horton earlier has quoted Geehardus Vos on page 88 of his book as seeing a connection between the Covenant of redemption and the Covenant of Creation (Works), in that the active obedience of Christ has its foundation in Christ fulfilling that aspect of the Covenant of Works on our behalf as our second Adam. In this section of Calvin's Institutes which has its chapter titled "Christ rightly and properly said to have merited grace and salvation for us", Calvin shows why it is proper to use the word merit when it comes to Christ's active obedience towards God. Earlier on in the first section (2.17.1) which was not quoted by Horton, Calvin proved that there is nothing wrong with using the word "merit' even though it may seem to make God a debtor (which God can never be). As Calvin says,
1. ... I admit that were Christ opposed simply, and by himself, to the justice of God, there could be no room for merit, because there cannot be found in man a worth which could make God a debtor; nay, as Augustine says most truly, "The Savior, the man Christ Jesus, is himself the brightest illustration of predestination and grace: his character as such was not procured by any antecedent merit of works or faith in his human nature. Tell me, I pray, how that man, when assumed into unity of person by the Word, co-eternal with the Father, as the only begotten Son of God, could merit this." — "Let the fountain of grace, therefore, appear in our head, whence, according to the measure of each, it is diffused through all his members. Every man, from the commencement of his faith, becomes a Christian, by the same grace by which that man from his formation became Christ." Again, in another passage, "There is not a more striking example of predestination than the Mediator himself. He who made him (without any antecedent merit in his will) of the seed of David a righteous man never to be unrighteous, also converts those who are members of his head from unrighteous into righteous," and so forth. Therefore, when we treat of the merit of Christ, we do not place the beginning in him, but we ascend to the ordination of God as the primary cause, because of his mere good pleasure he appointed a Mediator to purchase salvation for us. Hence the merit of Christ is inconsiderately opposed to the mercy of God. It is a well-known rule, that principal and accessory are not incompatible, and therefore there is nothing to prevent the justification of man from being the gratuitous result of the mere mercy of God, and, at the same time, to prevent the merit of Christ from intervening in subordination to this mercy. ...
Therefore such merit is not achieved by getting "plus points" as it were from God which is impossible, but as an expression of covenantal fulfilment/blessings. Christ's active obedience therefore gives us the righteousness we need to stand before God. The type in Adam was therefore required to similarly "merit" active righteousness by choosing good (eating of the tree of life) over evil (eating of the tree of the knowledge of good and evil).
Note: Just in case anyone was wondering, this is NOT an attempt to prove the Covenant of Works or any other doctrine from the Scriptures. This is rather an exercise in historical theology.