'The greatness of a nation and its moral progress,' Mahatma Gandhi said, 'can be judged by the way its animals are treated.' If we apply that test to the world as a whole, how much moral progress have we made over the past two millennia?

That question is suggested by The Golden Ass, arguably the world’s earliest surviving novel, written around 170 CE, when Emperor Marcus Aurelius ruled the Roman Empire. Apuleius, the author, was an African philosopher and writer, born in what is now the Algerian city of M’Daourouch. He learned Latin and Greek, completing his education in Athens and visiting Rome before returning to the region of his birth.

The Golden Ass is a first-person narrative told by Lucius, whose interest in magic takes him to Thessaly, a province of Greece renowned for the ability of its sorcerers. But his quest to learn the dark arts ends badly when he is turned into a donkey. In that guise, Lucius describes, from the animal’s viewpoint, the life of a lowly working animal in Roman times.

The various forms of mistreatment inflicted on the donkey fall into three categories. There is sadism: a slave boy for whom he carries wood gathered from the mountainside loves to torment him by beating him with clubs, adding rocks to make his load even heavier, tying stinging thorns to his tail, and finally, when he has a load of dry kindling on his back, dropping a live coal into it and igniting an inferno from which the donkey barely escapes with his life.

There is also brutality: he falls into the hands of a band of robbers who beat him mercilessly, not because they enjoy making him suffer, but to compel him to carry their stolen silver up endless rough and steep mountain paths to their hideout.

Finally, there is exploitation, ruthless but economically rational for the donkey’s new owner, a miller. In the mill, 24 hours a day, donkeys and horses turn the wheel that grinds the grain into flour. They are released from their exhausting labour only long enough to eat and sleep so that they will live to work another day. Overseeing their work, and beating them if they slacken off, are similarly exploited human slaves, clad in rags, with tattooed foreheads and shackled feet.

All of this makes The Golden Ass a remarkably progressive text. We have to jump forward 17 centuries before we find, in Anna Sewell’s Black Beauty, a comparably vivid and empathetic presentation of the life of an animal mistreated by humans. But what can we learn from this Roman work about moral progress since it was written?

In many countries, the sadistic cruelty of the slave boy and the brutality of the bandits would be illegal. That is progress, but it is far from universal. If Apuleius were to return today to the area where he was born, he would not find laws to protect animals from cruelty. Across North Africa, only Egypt has such legislation.

In West and Central Africa, animals are protected by law only in Ghana and Nigeria. Saudi Arabia, Iran, and China have no national animal welfare laws. In contrast, there is at least some level of legislative protection for animals across the whole of Europe (with the sole exception of Belarus), on the Indian sub-continent, in Japan, much of Southeast Asia (where Vietnam is the major exception), Australia and New Zealand, and most of the Americas.

Typically, these laws prohibit both sadistic cruelty and brutal beatings, although there is wide variation in enforcement. And because attitudes to animals also vary widely, animals may be better treated in some countries with no legal protection than they are in other countries where cruelty is illegal.

Consider developed countries, where the exploitation of animals for commercial purposes is a far larger problem. Worldwide, more than 70 billion land-based vertebrates are killed for food each year, and 90 percent of them live their entire lives inside factory farms. Although a few jurisdictions, especially the European Union, do prohibit the most extreme forms of confinement, in most of the world there are no barriers to treating animals in whatever manner maximises profit. A proposed United Nations Convention on Animal Health and Protection would help to remedy that situation.

In the mill that Apuleius describes, profits were maximised by working donkeys, horses, and human slaves nearly to death—but stopping just short of that point. If some of the animals (or slaves) did drop dead, well, it was cheaper to replace them than to ameliorate the working conditions that killed them.

Similarly, when giant agribusiness corporations decide how many animals to crowd inside their huge sheds, they know that the level of crowding that causes the fewest animals to die before reaching market weight will not be the most profitable level—and it is the latter benchmark that they will choose. As a result, more than 60 billion animals a year live miserable lives crowded into factory farms before being trucked to slaughter.

Gandhi’s criterion for judging the greatness of a nation and its moral progress is not limited to maltreatment of animals that is sadistic or brutal. It refers only to the way that the nation’s animals are treated. By that standard, as long as we keep most of the animals whose lives we control from birth to death in such appalling conditions, we cannot claim to have made much moral progress since Apuleius’s time.

—Project Syndicate