This book is an analysis of the role that the phenomenon of pneuma plays in the Fourth Gospel. Since Chrysostom, John’s Gospel has been valued as the most spiritual text among the New Testament writings. However, this recognition has not occasioned an examination of the Gospel in light of the idea of the pneu=ma as found in ancient philosophy, preeminently in Stoic physics. We find statements about the pneuma in the Gospel that, although traditionally considered as marginal and insignificant, are clarified significantly when situated within Stoic physics; e.g. the identification of God with pneuma.