This thesis examines the use of the terms Substitution and Representation as they are found to occur in Christian Atonement Theology. It is a theological investigation into the use of the terms, in order to establish their meaning and the relation between them. Both terms are first subjected to a phenomenological enquiry in order to disclose the various patterns of thought in which the terms function and which they help to generate. The part played by the terms within these different contexts, together with the models they espouse, are then critically analysed and evaluated. In this way the full complexity of the terms Substitution and Representation is examined, the appropriateness of their range of meanings tested, and the part they play in Christian Atonement Theology determined. To test the adequacy and accuracy of this analysis a more detailed study is made of the work of D. Sölle, Christ the Representative. Her place within the continuing debate surrounding the terms is established, and more light is shed on the use and meaning of the terms Substitution and Representation