Evolving divides

What do humans and animals share? And what sets them apart? Over the centuries, attitudes towards these two questions have varied. The perceived gap between the species at times widened and at times narrowed, before their disquieting proximity and the reality of animal intelligence and cultures was finally acknowledged. We take a look back at the nature of these changes.

Konrad Lorenz and his geese, in 1967. © Courtesy of the Konrad Lorenz Archive, Altenberg
Konrad Lorenz and his geese, in 1967. © Courtesy of the Konrad Lorenz Archive, Altenberg
René Descartes painted by Frans Hals.
René Descartes painted by Frans Hals.
One of the dogs used by Pavlov for his experiments (probably Baikal). A tube to collect his saliva was inserted surgically into his mouth. Photo kept at the Pavlov Museum in Ryazan (Russia). © GNU FDL
One of the dogs used by Pavlov for his experiments (probably Baikal). A tube to collect his saliva was inserted surgically into his mouth. Photo kept at the Pavlov Museum in Ryazan (Russia). © GNU FDL

What is humanity's position within the living world? The question is not insignificant; it is asked in all civilizations. In ancient Greece, philosophers were already divided into two camps. There were the ‘dualists', who believed in an ontological separation between the species, and the ‘continuists' who did not wish to place humans and animals in opposition. Among the former, the Stoics believed that humans possessed the superiority of reason while animals drew on instinct alone. The latter camp included most notably Aristotle, who believed that the living world as a whole possessed a psyche.(1) This theory accounted for a hierarchical continuum extending from plants to humans, by way of animals. Capable of sensation, desire and movement, animals would nevertheless be inferior to humans who possessed the prerogative of thought.

Thought immediately constitutes the dividing line. Montaigne, in the 16th century, shed his own light on the concept. He marvelled at the song of the blackbird and the way the spider wove its web, asserting that there were at times more differences between two people than between a person and an animal. Animals could reason, even engage in discourse and learn. To his mind, human superiority seemed overrated. However, only humans can arrive at universal notions through observations of the singular - in other words, engage in intellectual activities.

From Descartes to Darwin

But Descartes (1596-1650) soon occupied centre stage and his view that relegated the animal to the lower echelons dominated for a long time. This was the time of the first automatons, the anthropomorphic machines activated by hydraulic systems, and it was in such terms that the philosopher saw the animal- machine: mechanisms reduced to a body and in the service of humanity who is possessed of reason. "What seems to me a very strong argument to prove that the reason animals do not speak as we do is not that they lack the organs but that they have no thoughts," he wrote. Kant and Heidegger shared this view, as did the generations of human beings for whom the animal object represents an instrument in their everyday life, for their profession or for pleasure.(2)

We had to wait for Darwin (3) before this conception was swept aside. The main turning point came with the publication of his reference work on evolution, The Origin of Species (1859), in which he argued that living species have a common origin, and that evolution is governed by the mechanism of natural selection. Darwin, a Malthusian, based his theories on painstaking observations made during his famous trip, lasting nearly five years, on board The Beagle; during which he visited the Cape Verde Islands, the coast of South America, the Galapagos Islands, Australia and Tasmania. The observations were recorded in his Journal of researches. Darwin saw competition as the motor for survival ("It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change"). He then published Descent of Man in which he shows the proximity of human and animal species via an ancestor linked to the catarrhine monkeys.(4)

A giant step in humanity's thoughts on life had been taken. It was not until much later that genetics revealed that we share 99 % of our genes with chimpanzees. Yet this has not prevented creationist movements - who see life as governed by a superior causality and goal that is attributable to an ‘intelligent design' - from today contesting Darwinism.

Psychologists and ethologists

Darwin inspired passionate interest among psychologists who, during the 20th century, favoured laboratory observations. The most famous experiment is no doubt the one concerning Pavlov's dogs. Salivation was provoked when the dogs were shown food but when this stimulus was replaced by a visual or acoustic signal, the same salivation was triggered. This provided researchers with a means of testing the sensorial activities of animals. For behavioural psychologists, the favoured ‘guinea pigs' were white rats presented with labyrinths. These experiments were not designed to speculate on animal consciousness but to observe behaviour under controlled conditions, some of which were decidedly cruel. The Cartesian animal-machine reacting to stimuli and without any capacity to take its own initiative remained very much present.

In the 1930s, the first ethologists returned to the study of the natural environment, viewing the animal as a living being. At his house in Altenberg, on the banks of the Danube and surrounded by birds, the Austrian Konrad Lorenz (winner of the Nobel Prize for physiology and medicine in 1973) led the field in these observations. The jackdaw Tschok and the goose Martina became stars. It is the behaviour of the latter that his ‘master' had to thank for one of his most famous theories. Lorenz watched the wild goose hatch, waiting a while before entrusting it to one of his domestic geese and noticed that the gosling rejected this unknown guardian and preferred to follow him. His theory of imprinting, that is the existence of a very brief learning period during which animals attach themselves to the first object they see at birth, was published in 1927. Together with his friend, the Dutchman Niko Tinbergen, Lorenz also studied the concept of instinct by studying innate behaviour.

Their contemporary, Estonian zoologist Jacob von Uexhüll (1864-1944), marked a new stage when he turned his attention more to the significance of behaviour than its causes. He analysed the notion of Umwelt, the ‘surrounding world' experienced by the animal that captures things due to its particular sensorial apparatus. It is a world of signals. The animal is not a machine but is operating the controls. One of his favourite examples is the tick, which is blind and deaf, and whose thermal sense enables it to detect the presence of a hot-blooded mammal close by, onto which it allows itself to fall and attach itself, suck its blood, and as result enable its eggs, encapsulated since the time of mating, to develop. Ticks possess remarkable patience as some laboratory specimens waited 18 years before finding prey.

Animal intelligence

These experiments heralded cognitive ethology that over recent decades has revolu- tionised the approach to ‘animal intelligence'. Today we know far more about the learning processes, sex life, social relationships, tool use, inventiveness, self-awareness and socialisation of non-humans. What is more, these virtues are not the prerogatives of the great apes. In certain fields, the corvids would easily beat the chimpanzees. Elephants can recognise themselves in a mirror. London blue tits can open milk bottles placed on the doorsteps of houses. The killer whales of Canada have developed a surprising hunting technique that involves regurgitating their fish meals onto the surface of the water and waiting for a gull to swoop down, at which point they promptly devour it in turn. Alex, the grey parrot kept by Irène Pepperberg, a researcher at the University of Tucson (USA), was able to answer (by speaking, for course) the question of how many blue objects there were on a tray. In 2007, Japanese researchers showed, using videos, that chimpanzees beat students in a visual memory exercise that involved repositioning, in order, a set of numbers from one to nine.

These are just some of the many examples that could be cited - while not falling victim to the trap of egalitarianism. "You have to be a brute not to attribute suffering, interiority, subjectivity, and understanding to animals. But one risks falling prey to stupidity by continuing to deny that men feel, communicate, express themselves, and produce differently and better than even the most human of animals," believes Elisabeth de Fontenay, philosopher and author of Le silence des bêtes (The silence of the beasts), who has been working for many years on the relationship between humans and animals.(5)

Didier Buysse

  1. Term translated into Latin as anima, origin of the word animal.
  2. It was not until much later that animals were attributed rights. One of the first to express this idea was the American Thomas Regan (The case for animal rights - 1984) who defended the existence of moral rights for animals that, on the other hand, do not have obligations
    (see article called 'Oneself and others')
  3. See 'Man andbeast - inbrief'
  4. The catarrhines (from the Greek cata, meaning downwards, and rhinos, meaning nose), also known as Old World monkeys, are mainly present in Africa and Asia, whereas the platyrrhines, or New World monkeys, live mainly on the American continent. The former have nostrils that are close together and directed downwards while the latter possess nostrils that are far apart and directed sideways.
  5. Philosophie magazine, n°2, July 2006.