If such acquaintance is to be established, therefore, it must be established on the basis of other evidence. J. Weiss[31] seeks to establish it by the very fact of Paul's conversion. Paul, Weiss believes, saw a vision of the risen Christ. How did he know that the figure which appeared to him in the vision was Jesus? Why did he not think, for example, merely that it was the Messiah, who according to one strain of Jewish Messianic expectation was already existent in heaven? Apparently he recognized the person who appeared to him as Jesus of Nazareth. But how could he have recognized Him as Jesus unless he had seen Jesus before? [31] _Paulus und Jesus_, 1909, pp. 22, 23. Compare Ramsay, _The Teaching of Paul in Terms of the Present Day_, 1914, pp. 21-30. This argument depends, of course, altogether upon the naturalistic conception of the conversion of Paul, which regards the experience as an hallucination. In the account of the conversion given in the Book of Acts, on the contrary, it is distinctly said that far from recognizing the person who appeared to him, Paul was obliged to ask the question, "Who art thou, Lord?" and then received the answer, "I am Jesus." Such a conversation between Paul and the One who appeared to him is perfectly possible if there was a real appearance of the risen Christ, but it exceeds the ordinary limits of hallucinations. Weiss has therefore merely pointed out an additional psychological difficulty in explaining the experience of Paul as an hallucination, a difficulty which, on naturalistic principles, may have to be removed by the assumption that Paul had seen Jesus before the passion. But if Jesus really appeared to Paul in such a way as to be able to answer his questions, then it is not necessary to suppose that Paul recognized Him. The failure of Paul to recognize Jesus (according to the narrative in Acts) does not indeed positively exclude such previous acquaintance; the two disciples on the road to Emmaus, for example, also failed to recognize the Lord, though they had been acquainted with Him before. But, at any rate, if the supernaturalistic view of Paul's conversion be accepted, the experience sheds no light whatever upon any previous personal acquaintance with Jesus. Thus there is no clear evidence for supposing that Paul saw Jesus before the passion. At the same time there is no evidence to the contrary, except the evidence that is to be found in the silence of the Epistles.