dissenting.
The ex post facto clause1 of the Constitution prohibits Congress from enacting any law “which imposes a punishment for an act which was not punishable at the time it was committed; or imposes additional punishment to that then prescribed.” Cummings v. Missouri, 71 U.S. (4 Wall.) 277, 325-26, 18 L.Ed. 356 (1867). An ex *961post facto law must be retrospective and must disadvantage the offender affected by it. Weaver v. Graham, 450 U.S. 24, 29, 101 S.Ct. 960, 964, 67 L.Ed.2d 17 (1981). In this case we are asked to decide whether the denial of William Prater’s application for parole by the United States Parole Commission violates the ex post facto clause. Specifically, we must determine whether a prisoner may have his application for parole denied on the basis of a parole statute enacted only after his conviction. Today a majority of this court concludes that Prater’s continued detention does not violate the ex post facto clause. I cannot agree.
I
Our examination of this case must begin with a comparison of the two parole statutes at issue. Prior to 1976 federal parole law provided that “if it appears to the Board of Parole ... that there is a reasonable probability that such prisoner will live and remain at liberty without violating the laws, and if in the opinion of the Board such release is not incompatible with the welfare of society, the Board may in its discretion authorize the release of such prisoner on parole.” 18 U.S.C. § 4203(a) (1970 ed.) (emphasis added). Prater was denied parole on the basis of the Parole Commission and Reorganization Act of 1976 which provides that an inmate “shall be released” if release “would not depreciate the seriousness of his offense or promote disrespect for the law” and “would not jeopardize the public welfare.” 18 U.S.C. § 4206(a) (emphasis added).
As the majority points out, the ex post facto clause is relevant only to legislative enactments. Consequently, “all we should have to do to decide this case is compare the parole statute in force in 1969 with the statute enacted in 1976 under which Prater was denied parole.” Ante at 954. The majority then decides that the application of the 1976 statute does not offend the Constitution for two reasons: (1) “[t]he new statute considered as a whole is not harsher than the old,” ante at 955; and (2) “[t]he interpretation in section 2.13(b)(1) [of the 1973 parole guidelines] links the old statute to the new and shows that ... they have the same meaning.” Ante at 955.
The majority’s contention that the 1976 statute is “more liberal” than the 1969 statute, ante at 954, is, frankly, difficult to understand. The opinion for the court focuses on the fact that the old statute was “discretionary” whereas the new statute is “mandatory.” “The first reserves to the Commission discretion not to release the prisoner even if he meets the statutory conditions for parole; the second makes parole mandatory provided the statutory conditions are met.” Ante at 954. With all due respect, the majority’s emphasis on the discretionary and mandatory aspects of the two statutes is more ingenious than helpful. In the first place, a statute that vests discretion in a governmental entity is not necessarily more onerous or harsher than a statute that entitles an individual to a specific benefit upon the meeting of certain conditions. Discretion is often a quality of mercy. An individual like Prater, for example, who has committed a serious or notorious offense might well prefer to take his chances with the whim and caprice of the Parole Commission than with stringent and mandatory parole criteria. Without more, the fact that the 1969 statute is couched in the language of discretion and that the 1976 statute is couched in the language of entitlement tells us nothing about the relative severity of the statutes.
Second, it is important to remember that the discretionary/mandatory distinction becomes so critically important only because the majority chooses to frame the issue in those terms. No one just reading those two statutes would pay closer attention to whether the new statute is mandatory and the old statute discretionary. Instead, a disinterested reader would probably pay closer attention to the apparent change in the substantive criteria for determining parole eligibility. In ordinary English usage the phrase “incompatible with the welfare of society” connotes something entirely different from the phrase “would not depreci*962ate the seriousness of his offense or promote disrespect for the law.” The former phrase indicates a concern for the effect of the prisoner’s release on society. The latter phrase is directed toward the nature of the offense committed by the individual prisoner. Any impulse the average reader might have to equate the two phrases would be quickly deflected by the knowledge that the second statute, in addition to the “seriousness of the offense” criterion, includes a “public welfare” clause. The majority’s reading of the statute makes this second “public welfare” clause superfluous. The majority chooses to avoid a common sense reading of the statutes by incorrectly framing the issue as a dispute over the meaning of the shift from the language of discretion to the language of entitlement.
Finally, the majority’s idiosyncratic reading of the statutes directly conflicts with the Government’s position in this case. In the petition for rehearing and suggestion for rehearing en banc, the United States Attorney for the Southern District of Indiana asserts that “the Commission still enjoys the same discretion in granting parole as it did under the prior statute; and that discretion is written into the statute.” Petition for Rehearing at 6. The Government points out in its brief that 18 U.S.C. § 4206(c) states that “the Commission may grant or deny release on parole notwithstanding the guidelines referred to in subsection (a) of this section if it determines there is good cause for so doing.” (emphasis added). Elsewhere, the Government declares “that the strong language of the statute has been modified by additional language in the statute and the Commission’s discretion is intact so long as they [sic] observe some basic due process procedures.” Petition for Rehearing at 5 n. 3. Obviously, either the Government or this court is misreading the statutes.2 Ironically, our decision may serve to severely hamper the heretofore broad flexibility of the parole commissioners.
II
The majority’s second argument — that the 1973 guidelines prove that the two statutes mean the same thing — is deeply puzzling. The majority relies on that section of the 1973 guidelines which provides that “reasons for parole denial may include, but are not limited to ... (1) Release at this time would depreciate the seriousness of the offense committed and would thus be incompatible with the welfare of society.” 28 C.F.R. § 2.13(b) (1974). It is this provision that, according to the majority, “links the old statute to the new and shows that ... they have the same meaning.” Ante at 955. “The clincher,” we are told, “is the 1973 guidelines.” Ante at 955. What is puzzling about the majority’s reliance on the 1973 guidelines is that in the same opinion the majority takes great pains to point out that guidelines are not laws and that the ex post facto clause applies only to laws. “[T]he guidelines (at least so far as relevant to this case) are not laws within the meaning of the ex post facto clauses----” Ante at 954. Indeed, the majority summarily rejects Prater’s attempt to argue that the ex post facto clause does apply to parole guidelines. This court, as the majority points out, has previously held that parole guidelines are not laws for purposes of the ex post facto clauses. Inglese v. United States Parole Commission, 768 F.2d 932, 936 (7th Cir.1985). The 1973 guidelines are thus totally irrelevant to the question of whether the 1976 statute may be constitutionally applied to Prater. The internal logic of the majority’s own opinion prohibits it from relying on those guidelines. But without the guidelines we are left with only the bare language of the statutes and that language will not support the construction the majority would like to erect upon it.
*963III
The original panel opinion relied on an earlier decision of this court, Heirens v. Mizell, 729 F.2d 449 (7th Cir.1984), in holding that the question of whether an ex post facto violation has occurred is a question of fact. The original panel (of which I was a member) held that a reviewing court may inquire into the actual parole decisionmaking processes under the 1976 statute in order to determine whether an ex post facto violation had occurred. In retrospect I believe the original panel decision in Heir-ens was incorrectly decided and that it was wrong to have relied on Heirens. Because the ex post facto clause prohibition attaches only to legislative enactments, the question of whether an ex post facto violation has occurred is a matter of law. The sole issue in a case such as this is whether a new legislative enactment, on its face, has retroactive and detrimental effect. Welsh v. Mizell, 668 F.2d 328 (7th Cir. 1982), is the more accurate statement of the law and was, in my view, incorrectly overruled by Heirens.
The majority en banc opinion in this case carefully avoids a direct rejection of Heir-ens but clearly suggests that the Heirens approach is inconsistent with its general approach. The majority views the factual analysis undertaken in Heirens as unnecessary to support the result reached in that case. The inquiry into actual practice merely “cooked the petitioner’s goose.” The majority thus tacitly rejects the analytic approach of Heirens and in this, at least, I agree with the majority opinion. Moreover, the only question of law in this case relates to the exact meaning of the two parole statutes. To answer that question, we again have only one reliable guide: the bare language of the statutes themselves.
IV
Although I now disagree with the rationale of the original panel decision, I continue to believe that the application of the 1976 statute to William Prater violated the ex post facto clause. Since the majority has reminded us of the seriousness and brutality of the crime Prater stands convicted of conspiring to complete, it should be noted that after Prater’s initial parole hearing he was recommended for parole effective August 8, 1982. During his confinement he has had no disciplinary “write-ups” and has been gainfully employed in prison industries. He has no prior convictions and no history of drug dependence. He received the highest possible “salient factor” score of ten from the parole authorities. He is now sixty-seven years old. There really can be no serious doubt that Prater would not be in prison today but for the application of the 1976 “depreciate the seriousness of his offense” criterion and the majority virtually concedes the point. “Because of Prater’s age ... and because he was a model prisoner and had no prior convictions and no history of drug abuse, he might have been paroled upon first becoming eligible, had it not been for the notoriety of his crime.” Ante at 949.
The facts of the case and the language of the statutes speak for themselves. William Prater’s continued incarceration is unconstitutional. Today, that injustice receives the imprimatur of this court.
. U.S. Const. art. I, § 9, cl. 3 (“No Bill of Attainder or ex post facto law shall be passed.”). Art. I § 10, cl. 1 of the Constitution imposes the same limitation on the states.
. See also Inglese v. United States Parole Comm’n, 768 F.2d 932, 936 (7th Cir.1985) ("The statute, the parole regulations, and the policy statements contained therein clearly and repeatedly emphasize the discretionary aspect of the decision-making process of parole, particularly in the use of the guidelines.”).