In the Sistine Chapel, you look up at Michelangelo’s Last Judgment and see muscular angels hurtling through space, nude or with just a scrap of cloth tight across their buttocks (Figure 1, above). Then after leaving the Vatican, you browse a bookstall and find an illustrated sex manual, designed by another great artist, where your eye is drawn to the same figure driven by a different impulse (Figure 2).

Fig 2. Unknown artist’s copy of Marcantonio Raimondi’s I Modi, ‘Toscanini volume’, c1555. Private collection, Milan

Explaining this extraordinary resemblance inspired me to write Eros Visible: Art, Sexuality and Antiquity in Renaissance Italy (2017). On the book jacket (Figure 3), another of Michelangelo’s Sistine Chapel nudes strikes a provocative pose and swivels his eye to meet yours, as if to say: What do you make of this? The answer is that a little-recognised ‘erotic revolution’ swept through Italy between 1500 and the post-1550 Counter-Reformation.

Fig 3. Sistine Chapel detail from book jacket, Eros Visible by James Grantham Turner

Of course, some pictures were condemned as erotic even before 1500: Girolamo Savonarola, the fiery moral reformer of the 1490s, ordered his followers to toss them onto the ‘bonfire of vanities’. But broadly speaking, during the Middle Ages, depiction of sexual activities was confined to the low, comic or grotesque style, while nudity was extremely rare in high art (except in scenes of Hell), and figures tended to be slender rather than voluptuously rounded. Classical nude sculptures were sometimes destroyed or branded as the devil’s work. Courtly love was exalted, but lust and libido were condemned. Erotic feeling was most vividly expressed in mystic accounts of the ‘bridegroom’ Christ and his ‘bride’ the human soul.

The beauty of classical art was more highly valued in the early Renaissance (the 15th century), as was the love-theory of Plato. However, this led to an even deeper split between the pure ideal and base reality, between sacred and profane love. Neoplatonism polarised the celestial and the earthly Venus, and insisted that bodily experience must be expunged from true love. Beautiful figures in art were still mostly draped, and rare exceptions such as Botticelli’s The Birth of Venus were kept for private viewing and interpreted as strictly celestial. The questioning and collapse of these rigid distinctions is the erotic revolution.

Like most revolutions, this one was hardly total. It differed from the ‘sexual revolution’ of the 1960s in that it didn’t change social history, and no new contraceptive device liberated women from the endless cycle of marriage or prostitution. A more accurate phrase would be ‘erotic-aesthetic revolution’, radically changing the way that Italians conceived, created and thought about art. Great changes happened in the art world, which included the emergence of powerful patronesses, even though female artists and models were few. Passion and amore were valued as the wellsprings of creativity – not a distraction or pollution. Channels opened up between inspiration and arousal, between sacred and profane, between what is now separated into ‘art’ and ‘pornography’. Artists felt licensed to express all the passions and ‘motions of the soul’, not merely the chaste ones. Critics endorsed this by praising works that cause ‘whoever gazes’ to feel ‘an amorous fire/in their heart and their gestures’. Beauty was discovered in earthly as well as celestial love. Erotic response became the guarantee of the ‘living’ quality now most valued in art.

One way I measure this revolutionary change is by tracking key words such as lust or lascivious in writings about love and art. Philosophers of the Platonic school worshipped the celestial Venus – ‘chaste, orderly, superior, divine and spiritual’ – but denounced the lower, corporeal Venus as the root of all evil, ‘inferior, disorderly, variable, lascivious, animal, obscene’. Savonarola insisted on burning all ‘lascivious pictures’ (pitture lascive). Yet within an amazingly short time, lascivia was used without disapproval.

The writer Pietro Aretino justifies the Renaissance sex manual (Figure 2) by arguing that poets and artists have always amused themselves by making cose lascive, ‘lascivious things’. The patroness Isabella d’Este enjoyed art that was lascivo ma honesto, ‘lascivious but honourable’. In turn, artists were encouraged to bring out the ‘lascivious’ in their subject matter and in their sensuous brushwork, capturing the ‘living flesh’ and the excitement of falling in love. A wonderful description of Titian’s Venus and Adonis (Figure 4) praises the bisexual ‘mixture’ of masculine and feminine beauty in the ‘lascivious’ Adonis. The same Aretino promises the powerful ruler of Mantua a statue of Venus so ‘alive’ that it will ‘fill every viewer’s mind with libido’.

Fig 4. Venus and Adonis, Titian, 1554. Museo del Prado, Madrid. Courtesy Wikimedia

Leonardo da Vinci boasts that one of his religious paintings provoked ‘lust [libidine] in the owner’. For Leonardo, this is not a matter of shame but of pride in the superior power of painting, which ‘moves the senses more readily than poetry does’, and ‘depicts libidinous acts so lustful that they have incited viewers to play the same game’. The red-flag words libidinosi, lussuriosi and incitare shed their moralistic overtone. Leonardo in effect denies the fall of Adam and Eve and the shame that makes us hide the genital organ: ‘man is wrong to feel ashamed to name it, much less to display it, always covering and hiding what should be adorned and displayed with due solemnity’. Aretino justifies erotica in the same way:

What’s so bad about seeing a man mount on the back of a lady? So the animals should be freer than us? It would seem to me that the thingy that Nature gave us to preserve herself should be worn round the neck as a pendant, and in the cap as a medal … They should establish Holidays and consecrate Vigils and Festivals for it, not shut it up in a bit of cloth or silk.

Artists went ahead and visualised those ‘festivities’ (Figure 5).

Fig 5. Triumph of the Phallus, Francesco Salviati or follower, c1540. Private collection, Stockholm. Courtesy the author

This might all seem a phallocentric game that only elite males could join. In fact, I have found countercurrents to the alleged repudiation of female sexuality in accounts of the arousing effect of painting and sculpture. In Aretino, the viewer is ‘filled’ with the libido streaming from the Venus statue. Titian’s Venus melts and softens the viewer rather than giving him a hard-on: he ‘feels himself growing warm and tender, and the whole of his blood stirring in his veins’. Certainly the recipient is assumed to be male (the canvas was painted for Philip II of Spain, after all) but face-to-face with Venus’s bottom he is ‘penetrated to the marrow’.

As a final example of the revolution in action, consider another plate from that album of sexual postures, this time a lady mounting a man, a 19th-century reconstruction based on a tracing from a now-lost engraving (Figure 6).

Fig 6. Detail from Jean-Frédéric Maximilien de Waldeck’s reconstruction of I Modi, c1850. Courtesy British Museum, London

The posture comes from one of those ‘lascivious things’ that amused the ancient Romans, but the modern Roman artist made a scene of it: Aretino, who wrote sonnets on the whole set of positions, imagines the man yelling: ‘Cupid, you little fuck, stop pulling the cart!’ This ‘lascivious’ print then inspired one of the most entrancing images of the High Renaissance: Parmigianino’s love-god carving himself a new bow (Figure 7). Parmigianino’s Eros/Amor turns to lock eyes with us, and his implicit question is still: What do you make of this, do you like what you see?

Fig 7. Detail from Parmigianino’s Amor (or Cupid Fashioning his Bow), c1530. Courtesy Kunsthistorisches Museum, Vienna

At first, the answer was No. The art historian Giorgio Vasari, who celebrated the erotic art of his day, later condemned that posture manual as ‘ugly’, though without having seen it. The Counter-Reformation that started with the 1545 Council of Trent aimed to stamp out the sensuous and ‘lascivious’ elements that had allegedly contaminated religious art – especially Michelangelo’s Last Judgment. But reactions generate counterreactions so that, over the centuries, the lush sensuality of the High Renaissance has been celebrated, deplored and celebrated again repeatedly. Even now, after that other sexual ‘revolution’ of the 1960s, historians swing between a cerebral, idealising, Platonic approach and a deliberate campaign to put the body back into art, to value the erotic experience (of both sexes) and to question the division between ‘art’ and ‘pornography’.