Chapter 3 of Henri Blocher’s book Original Sindeals with discerning the mind of Paul on the issue of Adam and the Fall. Any Christian discussion of the evolution life, the evolution of homo sapiens, and the doctrine of Original Sin must reckon with Paul and his contrast between Adam and Christ. As death came through one man so life comes through one man. Romans 5:12-19 and to a lesser extent 1 Cor. 15:21-22, 45.
First the texts:

Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned–for until the Law sin was in the world, but sin is not imputed when there is no law. Nevertheless death reigned from Adam until Moses, even over those who had not sinned in the likeness of the offense of Adam, who is a type of Him who was to come. But the free gift is not like the transgression. For if by the transgression of the one the many died, much more did the grace of God and the gift by the grace of the one Man, Jesus Christ, abound to the many. The gift is not like that which came through the one who sinned; for on the one hand the judgment arose from one transgression resulting in condemnation, but on the other hand the free gift arose from many transgressions resulting in justification. For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ. So then as through one transgression there resulted condemnation to all men, even so through one act of righteousness there resulted justification of life to all men. For as through the one man’s disobedience the many were made sinners, even so through the obedience of the One the many will be made righteous. (Ro 5:12-19)
For since by a man came death, by a man also came the resurrection of the dead. For as in Adam all die, so also in Christ all will be made alive. (1 Cor 15:21-22)
So also it is written, “The first man, Adam, became a living soul.” The last Adam became a life-giving spirit. (1 Cor 15:45)

To deal with the question at hand we need to consider what these passages intend to teach about Adam, Original Sin, the transmission of sin, the nature of man, and role of Christ. Obviously we will not cover everything in one short post. But we can highlight some key points.
First — It is a non-negotiable for the orthodox Christian faith that Jesus Christ existed at a specific point in time in human history; that he was a unique individual who was crucified, dead, buried, and who rose again on the third day. We are saved, redeemed through the faith of Christ and through the act of Christ. The life, death, and resurrection of Jesus effected a change in actual being or enabled a future change in actual being for those who call upon his name.
Second — Ro 5 supported by 1 Cor. 15 appear to also require that Adam existed as a unique individual and that the act of Adam in rebellion against God was a unique act localized at a specific point in time. Certainly Blocher dismisses the notion that Adam was not a unique individual alive at a specific point in time. According to Blocher the Barthian interpretation of Adam as Every Man or Cosmic Man misrepresents Paul and it misrepresents scripture. Blocher finds support here in Dunn’s commentary on Romans 1-8. Paul undoubtedly viewed Adam as an individual and his transgression as historical. I admit, I (RJS) am not convinced Adam was a unique individual or that it matters that Paul thought he was – but this is an issue I am still thinking on. (I don’t know what Scot thinks here.)

But there is another concept intertwined with consideration of the Fall. Clearly what Paul thought and taught about sin matters. Romans 5 suggests that the sin of Adam results in the guilt of all mankind. But is this the case – is Paul actually proposing that sin and guilt are transmitted physically and biologically from Adam to all mankind? In an attempt to wrestle with the teaching of Paul, Blocher works through several interpretations of Romans 5 acknowledging a fundamental difficulty here for reformed theology in general.
A looser interpretation of Romans 5 (Dunn, Cranfield…) admits Adam as historical in some sense while rejecting a tight analogy between Adam and Christ. Paul’s emphasis is not on Adam and one act constituting all men as sinners as much as it is on Adam and the introduction of sin. All have sinned and fallen short of the glory of God. All excepting Jesus have lived sinful lives in their own right and are condemned on the basis of inclination and act. Ro 5:13 is something of an enigma here however.
A tighter interpretation of Romans 5 considers the sin of Adam as imputed to all mankind as all were present in the loins of Adam. The sin of Adam changed the nature of mankind. His sin and guilt are transmitted and reckoned to the account of all – even to the babe who dies within minutes or seconds of birth. Augustinian thought along this line has permeated much of the western church.
A proposal Blocher suggests that both the looser and tighter options hold an unjustified assumption. Paul did not consider sin as existing without law – it was simply undefined. Thus Romans 5 does not really deal with Original Sin. Perhaps the best course here is simply to quote Blocher: “My hypothesis, then, is as follows: I submit that the role of Adam and of his sin in Romans 5 is to make possible the imputation, the judicial treatment, of human sins. His role thus brings about the condemnation of all, and its sequel, death. If persons are considered individually, they have no standing with God, no relationship to his judgment. They are as it were, floating in a vacuum. Sin cannot be imputed. But God sees them in Adam and through Adam, in the framework of the covenant of creation. (p. 77)”
Well this begins to get quite deep. Blocher considers Adam as an historical individual and the original sin an important event – but appears to remove Romans 5 from a primary role in developing the doctrine of Original Sin. He also removes – although he does not say so specifically – the problem of considering how the sin of Adam changed the nature of mankind. The latter is a particularly difficult concept to reconcile with evolution as God’s creative mechanism. We will interact with Blocher’s ideas on Original Sin more completely in the last post on this book.
What do you think? Does Romans 5 teach that the Adamic sin changed the very nature of mankind? That sin and guilt are transmitted physically and biologically to his descendents?