If, however, the problem is not thus to be dismissed as insoluble, no unanimity has been achieved among those who attempt a solution. Two principal lines of solution of the problem may perhaps be distinguished--that which begins with the objective evidence as it presented itself to the persecutor, and that which starts with the seventh chapter of Romans and the persecutor's own sense of need. The former line was followed by Holsten, whose monographs still constitute the most elaborate exposition of the psychological process supposed to lie back of the conversion.[34] According to Holsten, the process centered in the consideration of the Cross of Christ. That consideration of course resulted at first in an attitude of hostility on the part of Paul. The Cross was a shameful thing; the proclamation of a crucified Messiah appeared, therefore, to the devout Pharisee as an outrageous blasphemy. But the disciples represented the Cross as in accordance with the will of God, and supported their contention by the evidence for the resurrection; the resurrection was made to overcome the offense of the Cross. But against the evidence for the resurrection, Holsten believes, Paul was helpless, the possibility of resurrection being fully recognized in his Pharisaic training. What then if the resurrection really vindicated the claims of Jesus to be the Messiah? Paul was by no means convinced, Holsten believes, that such was the case. But the possibility was necessarily in his mind, if only for the purposes of refutation. At this point Paul began to advance, according to Holsten, beyond the earlier disciples. On the assumption that the resurrection really did vindicate the claims of Jesus, the Cross would have to be explained. But an explanation lay ready to hand, and Paul applied this explanation with a thoroughness which the earlier disciples had not attained. The earlier disciples removed the offense of the Cross by representing the Cross as part of the plan of God for the Messiah; Paul exhibited the meaning of that plan much more clearly than they. He exhibited the meaning of the Cross by applying to it the category of vicarious suffering, which could be found, for example, in Isaiah liii. At this point the pre-Christian development of Paul was over. The Pauline "gnosis of the Cross" was already formed. Of course, before the conversion it was to Paul entirely a matter of supposition. On the supposition, still regarded as false, that the resurrection had really taken place, the Cross, far from being an offense, would become a glorious fact. All the essential elements of Paul's gospel of the Cross were thus present in Paul's mind before the conversion; the validity of them had been posited by him for the purposes of argument. The only thing that was lacking to make Paul a disciple of Jesus was conviction of the fact of the resurrection. That conviction was supplied by the Damascus experience. The unstable equilibrium then