Can a work of art criticism also be a spiritual book? When the subject is Michelangelo, the answer must be “yes”. As well as being a sculptor and painter of genius, Michelangelo was a man of deep piety; his art was informed by his faith. Thus to gaze on the extraordinary images he created on the Sistine Chapel ceiling is to be led on a spiritual journey. This book celebrates the 500th anniversary of the commencement of his “stupendous labour” (his own words) on 10 May 1508. Andrew Graham-Dixon, well-known as an art journalist, has written an excellent guide for the common man, complete with vivid colour illustrations of particular figures and a plan of the ceiling as a whole. (I could wish, however, a moratorium on the use of words such as “paranoid”, “megalomaniac” and “trauma”.)

Just occasionally the author gives the impression of being a sympathetic anthropologist surveying the exotic beliefs (Catholicism) of a colourful tribe on the planet Mars (Renaissance Rome). Thus, the ceiling is a great work of art “precisely because it does so much more than give visible form to a particular set of religious orthodoxies.” This suggests a possible tension between Michelangelo’s faith and its expression; I would argue rather, that there is a glorious fusion. I am reminded of a friend who once remarked of Dante: “Great poetry; pity about the theology.” Dante, incidentally, was the artist’s favourite poet.

The book begins with a brief outline of the artist’s life before Julius II gave him his papal commission to decorate the Vatican’s most famous chapel. It is salutary to recall that Michelangelo was only 23 when he executed the Pieta, possibly the most beautiful Madonna of them all, now in St Peter’s, and only in his mid-20s when he took over a misshapen block of marble that had been abandoned in a Florentine workshop to fashion his massive David. A sculptor before he was a painter, these two works of art, as the author emphasises, show both Michelangelo’s originality as a visual interpreter of Scripture and his “unique ability to hold all the elements of a [form] in his mind as if they were physical, three-dimensional presences.” In other words, the form was always there for him in the marble “as if it were simply waiting for him to reveal it.”

Graham-Dixon leans heavily on the biographies of the artist’s contemporaries, Vasari and Condivi, showing how Michelangelo directly influenced their portrayal to present himself – not inaccurately – as a lonely, solitary, God-driven man. “I can find peace nowhere,” was a poignant remark just before his death in 1564. After examining theories of the artist’s alleged homosexuality, the author briskly dismisses them; aside from a late, intense friendship with the Roman noblewoman Vittoria Colonna, Michelangelo allowed no one to get close to him. Not surprisingly given his achievements, his art – and through it his relationship to God – absorbed his entire being. Moderns, for whom naked bodies so often epitomise a prurient, sex-saturated society, forget that the heroic male nude, so splendidly evident on the Sistine Chapel ceiling, was essential to the art of the High Renaissance period. The artist used the nude to express a vast range of feelings and ideas; the creation of Adam is still intensely moving, despite its familiarity. Above all, for Michelangelo, “Man is always naked before God.”

The Sistine Chapel ceiling took four years to complete. Many years were to pass before the artist, at the behest of another pope, undertook to paint the wall behind the Chapel’s altar. This undertaking, from 1535 to 1541, was the Last Judgement. Just as with his earlier conception of God as boundless energy and creativity, here the Christ of Michelangelo’s imagination is daunting in the absolute authority conveyed by the movement of his arms and his exaggeratedly broadened torso. Graham-Dixon is not sympathetic towards this panorama of the end of human history; “an uneasy and unwelcoming work of art,” he terms it. I rather think this might partly be because the theology behind the painting is uneasy and unwelcome to him. Yet again, as with the first triad from the opening chapters of Genesis on the Sistine Ceiling, the viewer is left with the sense that Michelangelo has got the conception instinctively right.

In Islam, where there is no theology of the Incarnation and thus no intimacy between man and God, it is forbidden to attempt to depict the features of Allah. The dazzling arabesques of Muslim calligraphy at its finest cannot compensate for the absence of a human dimension. Michelangelo, a man who must have deeply meditated his Christian faith, brings us the greatest achievement of Western art: an indelible image of God, at once majestic and passionate.

As I was writing this review I noticed a newspaper headline and was instantly plummeted from the divine to the ridiculous: “Did Michelangelo hide Kabbalah codes in the Sistine Chapel ceiling?” it read. Graham-Dixon has anticipated such nonsense:  to approach the ceiling “in quest of secret meanings and veiled correspondences seems fundamentally perverse.”

Francis Phillips writes from Bucks, in the UK.