Prolegomena is the study of presuppositions, definitions and theological methods which are foundational to any doctrinal system. This volume concerning prolegomena is decidedly dispensational in approach and thus lays the groundwork necessary for understanding Scripture dispensationally.
Cone, among other things, handles issues related to the existence of God, Scripture, hermeneutics and theology. He spends over a third of the book discussing hermeneutical matters and defending the Historical-Grammatical method. He deals much with Dispensationalism and distinguishes it from Covenant Theology.
I believe Cone has done his homework and offers an excellent theological study which is basic to systemic theology.