“They’d need to justify not doing that,” he said. “Why apes?”

Spain’s Catholic bishops attacked the vote as undermining a divine will that placed humans above animals. One said such thinking led to abortion, euthanasia and ethnic cleansing.

But given that even some humans are denied human rights, what is the most basic right? To not be killed for food, perhaps?

Ten years ago, I stood in a clearing in the Cameroonian jungle, asking a hunter to hold up for my camera half the baby gorilla he had split and butterflied for smoking.

My distress  partly faked, since I was also feeling triumphant, having come this far hoping to find exactly such a scene  struck him as funny. “A gorilla is still meat,” said my guide, a former gorilla hunter himself. “It has no soul.”

So he agrees with Spain’s bishops. But it was an interesting observation for a West African to make. He looked much like the guy on the famous engraving adopted as a coat of arms by British abolitionists: a slave in shackles, kneeling to either beg or pray. Below it the motto: Am I Not a Man, and a Brother?

Whether or not Africans had souls  whether they were human in God’s eyes, capable of salvation  underlay much of the colonial debate about slavery. They were granted human rights on a sliding scale: as slaves, they were property; in the United States Constitution a slave counted as only three-fifths of a person.

As Ms. Newkirk pointed out, “All these supremacist notions take a long time to erode.”

She compared the rights of animals to those of women: it only seems like a long time, she said, since they got the vote or were admitted to medical schools. Or, she might have added, to the seminary. Though no Catholic bishop would suggest that women lack souls, it will be quite a while before a female bishop denounces Spain’s Parliament.