This thesis investigates the symbolic universe of Paul's social world to interpret his slave metaphors in his letter to the Galatians. It adopts the approach to metaphor belonging to the 'New Rhetoric' of C. Perelman and L. Olbrechts- Tyteca, which not only deals with the formation of metaphors but also incorporates the formation process into the interpretive model for metaphors. This approach enables a nuanced account of the various argumentative functions of Paul's slave metaphors in Galatians. The findings are related to the question of Paul's own convictions regarding slavery as witnessed in Galatians 3.28. In order to interpret the process and meaning of Paul's slave metaphors, this study investigates the social context from which Paul formed his metaphors, namely Greco-Roman slavery in the first century. This context provides the better-known area of discourse (the 'phoros') under which aspect the lesser- known area is presented (the 'theme') in a metaphor (a fusion of theme and phoros). Galatians evidences three distinct slave metaphors, revolving around Paul as a 'slave' of Christ, the 'enslavement' threatened by Paul's 'opponents', and the manumission, adoption, and potential re-enslavement of his Galatian converts. The route from Paul's metaphors to his own convictions about slavery is indirect, but the latter will be of vital interest to contemporary readers. This thesis raises the question of Paul's convictions only after working carefully through the argumentative functions of Paul's metaphors. Raising the question in this way, one is able to provide a more circumspect answer than is sometimes found when this latter question is placed to the fore. In his letters, Paul's concerns are not those of the modern reader. Instead, he used what he could from his environment.