Jürgen Moltmann's first major work, Theology of Hope, first published in 1964, is arguably one of the truly great theological works of the last few decades, and indisputably one of the most influential. Though Moltmann's own theology has developed considerably in many subsequent works since Theology of Hope, it remains one of his greatest achievements, rivalled only by his second major work, The Crucified God. These two books, which constitute the core of Moltmann's early theology, have, it seems to me, a concentrated power of argument, focused on their central integrating ideas, which is lacking in the more diffuse structure and argument of the later works, significant though these are in their own way. The two early books also have a certain polemical extremeness, which, by contrast with the more balanced and rounded quality of the later works, gives them the sort of impact which one also finds in the passionate extremism of the early Luther or the dialectical rhetoric of the early Barth. The comparison is appropriate, not only because the influence of these two predecessors on Moltmann's work is very evident, but also because, in adopting something of their dialectical and prophetic style of theology, Moltmann had a parallel purpose: that of redirecting theological work. If, having accomplished this, Moltmann has subsequently become more and more like the older Barth of the Church Dogmatics, this is understandable and brings both advantages and disadvantages with it.
