In the introduction to the Cambridge Companion to C.S. Lewis, editor Robert MacSwain considers whether a volume on Lewis even belongs in the Cambridge series on religion, rather than, say, literature, which was after all Lewis’s day job and primary area of expertise. Moreover, academic theologians have generally ignored, if not disdained, Lewis and his contributions to theology. MacSwain suggests that what might be needed is an expansion of our concept of theology beyond the familiar academic model:

[I]t may … be the case that Lewis should rightly be considered in this particular series because he has, in fact, expanded the genre of theology to include the imaginative works for which he is so famous. Thus, instead of an amateur, dilettante theologian who cannot possibly be considered in the same league as, for example, Barth, Gutierrez or Moltmann, Lewis might rather be seen (a la Kierkegaard) as a deliberately ‘indirect’ theologian, as one who works by ‘thick description’ or evocative images, operating in multiple voices and genres, through which a single yet surprisingly subtle and complex vision emerges. Yes, of course it is ludicrous to compare Lewis’s Mere Christianity to Barth’s Church Dogmatics–but perhaps it is equally ludicrous to let Barth define the character of all theology. And when Lewis’s entire output is considered as a whole, the comparison might not be so ridiculous after all. Lewis cannot possibly count as a theologian on the Barthian model, but he may nevertheless offer a model of theological expression which needs to be appreciated on its own terms. (pp. 8-9)

The books itself includes essays on all aspects of Lewis’s output (as scholar, thinker, and writer) from top-notch figures in various fields. Theology is represented by Kevin Vanhoozer, Paul Fiddes, and Stanley Hauerwas among others. And the volume as a whole certainly makes a persuasive case for taking Lewis seriously as a thinker (i.e., not someone to be uncritically venerated or dismissed).