BOOK REVIEW / On the animal revelation front: 'The Duty of Mercy' - Humphrey Primatt: Centaur Press, 8.99 pounds: Jan Morris applauds an 18th-century anglican vicar and his unusual early enthusiasm for animal rights

ONE DAY in the 1770s a retired Anglican vicar, the Reverend Humphry Primatt, D D (Aberdeen), sat down in his library in Kingston-on-Thames and wrote a short devout book about the relationship between mankind and the rest of the animal world. Others of his century - Pope, Addison, Steele, Bentham - had deplored cruelty to animals. Dr Primatt's distinction was that he approached the subject from the standpoint of a clergyman of the Established Church; and Christianity being what it is, 116 years later his book is as topical as ever. A few years ago I threw myself upon an unfortunate Episcopalian Bishop for his use of the phrase 'the sanctity of human life' - as if no other form of life was holy - but he did not even understand what I was angry about.

For even now the issue of animal rights, for so long entrammelled in crankiness, is only hesitantly emerging into the mainstream of ethical debate. This reprint of The Duty of Mercy, the first since 1834, is one of a series of related books published by Centaur Press in their Kinship Library, dedicated to Albert Schweitzer's proposition that man will never find peace until he 'extends his circle of compassion to all living things'.

Down the generations a small and often derided minority has opposed the conviction that man alone, among all the creatures, should enjoy rights. As an early activist in the cause Dr Primatt was remarkable because he was a priest of a faith so generally oblivious to the idea. He composed his book in the conventional form of an 18th-century theological treatise, but his attitudes were radical.

Kindness to animals, Dr Primatt argued (or as he put it in the language of the day, 'mercy to brutes') was a doctrine of divine revelation. This was brave talk to the followers of a creed which, so far as I know, never suggested any such thing. Mohammed, we are told, hated to disturb the cat that slept upon his sleeve, but we hear nothing of Jesus's feelings for animals, except in an allegorical kind, and nothing in his message suggests that they have any call upon the eternal mercy. Yet this pious elderly clergyman set out in his tract to demonstrate that they, too, form part of God's pattern of infinite compassion.

'Every creature is to be considered,' he tells us, 'as a wheel in the great machinery of nature,' and thus no animal is contemptible - even the ugly ones, he rather desperately proposes, may have been created 'to set off the beauties of the perfect'. To despise an animal because of its form or kind is no better than to bully a black man because of his colour, or to trample upon a dwarf because he is small. One can sin against animals, in short, just as one can sin against humans.

Even today this proposition is by no means universally accepted. Dr Primatt was further handicapped, in trying to convince people of it, by having to work within all the restraints of his calling, so that much of the book is an attempt to reconcile his private views with the dogmas of his faith. This sometimes makes for heavy going.

The dear old boy works in the genre best known to him, so that the book is full of textual allusions, theological conceits and footnotes familiar to all readers of holy tracts.

Of course he ransacks the Old Testament for quotations to support his thesis. Go to the ant, says Solomon, consider her ways and be wise. The stork knoweth the appointed times, cries Jeremiah, but my people know not the judgement of the Lord. Both man and the animals, Genesis tells us, were formed 'of the ground', and the Psalms assure us that the Lord giveth to the beast his food, and feedeth the young ravens. 'Wherefore,' demanded the stern angel of Balaam, in the Bible's chief gift to the RSPCA, 'hast thou smitten thine ass these three times?'

But Dr Primatt was no sentimental idealist. He does not pretend that Balaam had no right to enslave the ass at all. He never goes so far as to claim that the animals are our equals before God, still less to suggest they are endowed with immortal souls. His proposal is simply that it is as wicked to make animals suffer as it is to make humans suffer. 'Cruelty is atheism,' he declares, whether it is cruelty to a brother, a black slave, a dwarf or a donkey. One could hardly expect more, from a loyal cleric of the 18th century.