‘I saw the best minds of my generation destroyed by cat videos,’ begins Henry Mance’s How to Love Animals, winningly. That is the paradox he sets out to unpick in this densely factual and intermittently horrifying book: how a world in thrall to cuteness, endlessly compelled to click on videos of kittens and owls having a special friendship, can remain indifferent to the suffering of almost all other animals, whether farmed, in captivity or in the wild.