I have recently been reading Professor Alister McGrath’s magisterial textbook of theology, mostly by night on a palm-fringed terrace in Mauritius, where the many mosquitoes did their utmost to keep me from the knowledge of God. It’s fascinating to see philosophy approached from a different angle, to uncover a total system of understanding on the same scale as that of Plato, Aristotle, or Kant. These are the ideas that have defined our civilisation and that continue to shape and colour our lives, whether we appreciate it (in both senses of the term) or not.

Once theologians such as Karl Barth, Jean Calvin, St Aquinas (the Doctor Angelus), or Duns Scotus (the Doctor Subtilis) are placed in their historical and sociocultural context, they become anything but dry and irrelevant, and many of the questions that they raise remain of the greatest and most universal philosophical and psychological import. Indeed, not for nothing does the University of Oxford accord the highest rank to the Doctor of Divinity.

Something that stood out in my reading is the theological interpretation of a common human experience, namely, the curious sense of longing for something undefined. According to St Augustine, this feeling of dissatisfaction arises from man’s fallen condition. Although man has an innate potential to relate to God (substitute ‘the absolute’ or ‘the infinite’ if you are discomfited by the religious connotations of the term ‘God’), this potential can never be fully realised, and so he yearns for other things to substitute for it. Yet these other things do not satisfy, and he is left with an insatiable feeling of longing – longing for something that cannot be defined.

CS Lewis elaborates on Augustine’s maxim that desiderium sinus cordis (‘longing makes the heart deep’) by arguing that no earthly object or experience can satisfy man’s profound and intense feeling of longing. Lewis calls this feeling of longing ‘joy’, which he defines as ‘an unsatisfied desire which is itself more desirable than any other satisfaction’. (I kind of see it as our aesthetic reservoir, in the broadest sense.)

This paradox arises from the self-defeating nature of human desire, such that the fulfilling of a desire yet leaves it unsatisfied. Lewis illustrates this from the age-old quest for beauty,

The books or the music in which we thought the beauty was located will betray us if we trust to them; it was not in them, it only came through them, and what came through them was longing. These things – the beauty, the memory of our own past – are good images of what we really desire; but if they are mistaken for the thing itself they turn into dumb idols, breaking the hearts of their worshippers. For they are not the thing itself; they are only the scent of a flower we have not found, the echo of a tune we have not heard, news from a country we have not visited.