(_b_) Much of the technical phraseology common to Paul and the Hermetic literature is current in the Old Testament; and with the language of the Old Testament we know that Paul's mind was saturated. Clemen's maxim should be observed, and we should seek the source of an idea (or word) in the native religion before going farther afield. Thus before Paul's doctrine of the Spirit is assigned with confidence to Hellenistic sources, the use of the term Spirit both in the Old Testament and in pre-Pauline Christianity should be studied. Paul quotes the passage from Joel which promises the outpouring of the Spirit (Rom. x. 13 f.; see Acts ii. 21). He brings the Spirit into connection with the blessing of Abraham (Gal. iii. 14). The Spirit is also mentioned in the introduction to the ministry of Jesus alike by Mark and by the non-Markan source. A sufficient and natural explanation of Paul's doctrine of the Spirit is to be found in the Old Testament, in Evangelical tradition and in the experience of the church at Pentecost, and in his own experience. When Paul speaks of "the Spirit of adoption whereby we cry, 'Abba, Father'" (Rom. viii. 15; Gal. iv. 6), we have to do not with remote literary influences nor with the dry bones of any technical theology, Hebraic or Hermetic, but with the heart-throb of personal experience. Reitzenstein believes that the Pauline vocabulary is best explained by the Hellenistic parallels, but he recognizes that the parallelism with the Old Testament should be considered. Thus while he thinks that he has shown parallels for all the Pauline uses of the word _pneuma_, he says "whether with equal ease all may be explained from the Hebraic use of _ruach_ and _nephesh_ or the use of _pneuma_ in the Septuagint the theologian must decide."[249] Harnack, with some irony, advises Reitzenstein and his school to gain a clearer knowledge of Paul the Jew and Paul the Christian before they take account of secondary elements which he borrowed from the Greek mysteries. A conscious acceptance, he thinks, of such elements is out of the question.[250] 249: "H. M. R.," p. 140. 250: "Date of the Acts and of the Synoptic Gospels," p. 61 n. Kennedy believes that the vocabulary of Paul is to be explained from the Old Testament, while much of it was current among the mystery brotherhoods (_Op. cit._, p. 198). Bousset acknowledges that Paul's terminology may perhaps in part be derived from the Old Testament, which would be the most natural source of his use of _pneuma_ instead of _nous_ to describe the spiritual part of man, and of the opposition in words between _pneuma_ and _sarx_ (_Op. cit._, p. 141, note 2). Clemen ("Der Einfluss der Mysterienreligionen auf das älteste Christentums," 1913, p. 61) says that "looked at broadly, Paul remains in verbal and much more in actual relationships untouched by the mystery religions."