They are some of the best-known adverts in television history. Families of chimpanzees in human clothes, riding bicycles, pouring tea and even driving cars. They were made to advertise PG Tips, the most popular brand of tea in Britain. But were they exploiting the animal actors?

In the year 2000, PG Tips stopped using chimps to sell tea. Nowadays, tastes have changed and the adverts look old-fashioned. In fact, the Spanish government is considering a law that would completely ban the use of chimps for commercial purposes, including circuses, shows and advertising.

It is not just chimps that Spain wants to protect. The law relates to the entire great apeThe Hominidae or Hominid family of primates, including orangutans, gorillas, chimpanzees, bonobos and humans. family of primates, which includes gorillas, orangutans and bonobos. As well as commercial use, the law would ban scientific testing if it causes harm, and impose strict rules on ownership.¹

The proposed law argues that these animals are the distant cousins of another great ape: humans. We all belong to the category Hominidae, with a common ancestorA person related to us who lived a long time ago. that lived 14 million years ago. If it is wrong to experiment on humans, surely it is wrong to do the same with gorillas or orangutans?

At present, 29 countries around the world have passed laws protecting great apes from harmful research.² The entire EUEuropean Union. An economic and political union of 27 countries. banned great ape experimentation in 2013, but the law in Spain goes beyond science. As the document argues, great apes have cognitive abilities that "bring them close to those of human beings".³

Peter Singer, the respected philosopher, is one of many academics who support the proposal. He founded the Great Ape Project, a group campaigning for great apes to be granted rights to life, libertyFreedom. and protection from torture. And he praised the Spanish government for respecting the "dignity" of these animals.⁴

But others have concerns about the legislation. Many animals have some cognitive ability, but are still used in scientific research, or else farmed for meat and other products. Why should great apes be given "dignity," but not horses, cows, or dogs?

At the centre of this debate is the concept of personhood. These are the qualities that make people distinct from animals and deserving of human rights, protections and privileges. But this concept can be difficult to define.

For example, many philosophers argue that humans have a unique capacity for self-awareness, empathyThe capacity to understand and feel the suffering of others. and the ability to understand complex rules or think abstractly. But there are humans who do not share these abilities - young children, or people with learning difficulties - who still count as persons.

In recent years, some scientists have argued that personhood should be applied to great apes, and some lawyers have argued that personhood should be applied to all animals. ⁵ There are even environmental activists who believe ecosystems like forests or rivers could qualify. Sure enough, if Spain passes this law, the idea of personhood will only grow bigger.

Is this morally right?

Yes: Humans and great apes share a common ancestor and similar levels of cognitive ability. Therefore, they should be given the same rights and protections that people enjoy.

No: If cognitive ability means an animal should be treated like a human, we cannot simply protect great apes. Farming animals for food, dairy, or leather will also have to be stopped.

Or... It can be hard to draw a clear dividing line between humans and animals. But, if we do not draw a line somewhere, the concept of personhood becomes meaningless.