Before modern times, philosophers took music extremely seriously. Its role in shaping and revealing the human soul was of enormous concern to Plato and Aristotle. The Pythagorean cosmology was founded on the ancient theory of harmony. And music is treated by the 10th-century Muslim philosopher al-Farabi as one of the primary themes of philosophical speculation.

Neither rationalists nor empiricists gave much attention to it, and it was not until Rousseau that a major philosopher was again to regard music as an art of supreme moral and political importance. Moreover, Rousseau was the first philosopher since al-Farabi to pursue a musical career.

Nietzsche is explicitly compared to Rousseau in Georges Liébert’s superbly erudite and serious study. Like Rousseau, Nietzsche fancied himself as a composer; like Rousseau he engaged in vehement polemics against the music of his time (in this case, against the cult of Wagner); and like Rousseau he believed that the state of a musical culture is indicative of the entire moral climate of an epoch.

Nietzsche’s compositions have now been published, and many issued on CD. There are some charming songs in the manner of Schumann, some grandiose attempts at choral and orchestral fantasias and massive splurges for piano with fraught romantic titles like Hymn to Friendship. Nietzsche was at best what he so unjustly and outrageously accused Wagner of being: a miniaturist, whose short-breathed successes are inspired by solitary and lachrymose emotions that could not bear to be pursued at greater length. The works for which he would have wished to be remembered are formless improvisations, with lunatic bass-lines and grotesque progressions, entirely devoid of melodic or harmonic logic.

Nietzsche knew this, and turned to literature with a sense of opting for second best. He even described Also sprach Zarathustra as a work of music, hoping to gain by metaphor what he could not achieve in fact. And throughout his troubled and lonely literary career he took what consolation he could from the fact that he, unlike his critics, had the soul of a musician, and could hear his way into the secret heart of things. His prose was an attempt to convey the wordless truths, the primeval needs and hopes, that find their true voice in music. All this is beautifully outlined by Liébert in a manner that is as clear as it is thoughtful.

Liébert devotes considerable space to Nietzsche’s love-hate relation with Wagner, which was really a love-hate relation with himself. Through careful analysis and apt quotation he shows how deeply self-deceived the philosopher was, both in his initial admiration for the composer, and in his subsequent petulant break with him.

At the very moment when he was publicly denouncing Parsifal as a work of sickness, decadence and deception, Nietzsche sends to his friend Peter Gast a wonderful description of the Prelude to that work, and confesses, in his notes written prior to Beyond Good and Evil, that he knows “of nothing that grasps Christianity at such a depth and that so sharply leads to compassion”. Parsifal captures the dramatic and emotional logic of the Christian vision, and Nietzsche’s own aesthetic compelled him to recognise this and to see it as an artistic triumph. So he denounced the work on the very grounds that should have led him to praise it.

Not everything that Nietzsche wrote about music is as self-involved as his public joust with Wagner. He was surely right in his belief that the state of a musical culture is testimony to the moral condition of those who belong to it. In this he laid the ground for a new kind of music criticism, and — even if he meandered off into his own barmy thoughts about North v South, Christian v Pagan, Germans v the rest — he deserves respect for his recognition that music doesn’t merely echo the world, but also changes it. Liébert’s book adds considerably to our knowledge of a philosopher who still brilliantly shines like a lighthouse above the treacherous sea of his mistakes.

Roger Scruton’s Death- Devoted Heart: Sex and the Sacred in Wagner’s Tristan and Isolde is published by Oxford University Press, £17.99

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