About twenty years ago, a musician friend played at a pub in deepest Wiltshire and was invited to a lock-in. In the small hours, the pub was electrified by the news that Nobby Lippett was on his way. My friend was still wondering who this local hero could be, and why everyone was so excited, when his hosts led him to a barn along with most of the men in the pub. The publican collected £20 from each of them, and then everyone watched Nobby Lippett having sex with a sheep.

Having given practical proof of his nickname and elicited a round of applause by ejaculating on the sheep’s back, Mr Lippett and his companion then disappeared in his van; like an old music hall turn, they worked several stages on Saturday nights. The worst part, my friend said on his return to civilization, was that the sheep seemed fine with it.

Did the sheep consent? Mr Lippett was evidently an experienced agriculturalist; if anyone could take a bleat for “Yes”, it was him. But can an animal construe abstract human concepts like consent or love? And if an animal is seen to comply, does that reflect what we understand as free will, or “grooming” akin to the kind of training that makes children comply with sexual abuse?

“Sex with animals is one of the last taboos,” Joanna Bourke writes in Loving Animals, “the final bastion of human exceptionalism.” Bourke’s “fundamental premise” in this work of sophisticated depravity is that “bestiality is not an affront to the ‘dignity of man’; nor does it ‘degrade people below the level of animals’, as Immanuel Kant decreed”.

The master obfuscator Jacques Derrida described human-animal relations as “carno-phallogocentrism”: privileging “masculine traits (‘phallo’) and the possession of language (‘logos’)” and being willing “to kill and eat other sentient beings (‘carno’)”. Nobby Lippett would no doubt agree with Bourne’s critique of Kantian carno-phallogocentrism. But Linda Lovelace, who had rather more Erlebnis to draw on than the sage of Koenigsberg, differs.

Lovelace, in the catalogue of abuse that is her autobiography, describes how, in 1972, her boyfriend and pimp Chuck Traynor, beat her and threatened her with death in order to force her into having sex on film with a dog named Norman. When Norman entered the set, she had “the eerie sensation that he knew more about what was going to happen than I did”. Lovelace had been “raped by men who were no better than animals, but this was an actual animal”. Sex with Norman crossed “a huge dividing line”. If she could have “foreseen how bad it was going to be”, she would “have chosen the possibility of death”.

Bourke, using “queer theory” as a moral lubricant, argues that sex between humans and animals doesn’t have to be degrading to humans, and that what really offends us is the idea of “upgrading animals”. The limits are obvious even to philosophers: the conditioning infringes the animal’s right to a free development it cannot consciously understand. Bourke seeks instead to arrive at an “ethics of animal-loving” by degrading the human side of the partnership.

Bourke defines deviancy down by emphasizing the violation of animals for food: “Dairy cows are, in effect, sexual workers, being kept continuously pregnant . . . The artificial insemination of pigs, for example, sometimes requires farmers to simulate mounting and fondling.” Compared to the Herriott-like cruelty of animal husbandry “in the interest of capitalist production”, what’s a little non-phallogenital frottage between species?

The obstacle, Bourke reckons, to enjoying “the carnal joys of truly loving animals” is the patriarchy. Bourke endorses the philosopher Monica Bakke, who believes that “zoopleasures” disrupt the “anthropocentric order” by offering an “alternative to phallocentric models of eroticism”. In other words, rural recreationist Nobby Lippett is a wrong ‘un, but “feminist philosopher” Donna Haraway is on the right track when she boasts of training her dog Cayenne Pepper to lick her tonsils.

The obstacle, Bourke reckons, to enjoying ‘the carnal joys of truly loving animals’ is the patriarchy

Bourne is too sophisticated to see the elephant in the bedroom. The data she adduces suggests not just a close correlation between rape and bestiality, but also that young men from rural areas rape animals because they are sexually frustrated. It is loneliness that directs human desires towards the four-legged objects of our narcissism: the silly names, the absurd selection of dogs whose physiognomy and hair are a cartoon of their owners, the witless mock-conversations conducted for the benefit of other humans — that, and the knowledge that they won’t bite back, for we breed them for docility: we keep labradoodles, not wolves. Our pets are also lonely. We isolate them from their species unless we unlock the cat-flap or let them off the leash in the park, and we condition them to serve our desires.

Don’t worry, Bourke doesn’t justify paedophilic sex. But she does use it to justify sex with dogs. Children, she writes, “might not be able to understand the psychosocial significance of the sexual act” — note that cheekily subversive “might” — but they will subsequently suffer a “traumatic” understanding when they are themselves adult. In contrast, the dog “who approaches and voluntarily mounts a human is following his own species-specific ‘meaning’”. But Nobby Lippett could have told us that. Bestialists, radical agriculturalists and fashionable intellectuals will enjoy this book, especially the pictures.