In common parlance, the word ‘soul’ pops up everywhere. We may speak of a vast, soulless corporation or describe an athlete as the ‘heart and soul’ of his team. Soul music gets us swaying. We want our lover, body and soul. In each case, ‘soul’ connotes deep feeling and core values. ‘Feelings form the basis for what humans have described for millennia as the … soul or spirit,’ the neuroscientist Antonio Damasio eloquently expounds in his groundbreaking book Descartes’ Error (1994).

Today, studies increasingly show that many non-human beings feel. Elephants appear to feel grief, while dolphins and whales express joy, or something much like it. Parrots can become cranky, pigs and cows terrified, chickens saddened, monkeys seemingly embarrassed. Experiments have shown that rats become agitated when seeing surgery performed on other rats and that, when presented with a trapped lab-mate and a piece of chocolate, they will free their caged brethren before eating. There’s even evidence that rats take pleasure in being tickled.

None of this will come as a surprise to pet owners or anyone who has observed virtually any kind of animal for any length of time. Science is rediscovering what Charles Darwin, in his book The Expression of the Emotions in Man and Animals (1872) concluded: that the variations between humans and other species in their capacity to feel and express emotion are differences in degree rather than in kind. It’s a short step from there to recognition that individual animals have personalities, and to reckon that not only do they live – they have lives.

One might even argue that other creatures are more cognisant of feelings than humans are, because they possess a primary form of consciousness: they are aware of themselves and their environment but are less burdened by complexities such as reflection and rumination that typify human consciousness. They live closer to the bone, so to speak. Jeffrey Masson, author of When Elephants Weep (1995), has remarked that animals possess feelings of ‘undiluted purity and clarity’ compared to the ‘seeming opacity and inaccessibility of human feelings.’ Furthermore, we should consider that humans may not experience the full range of feelings found in the animal kingdom. As Humane Society ethologist Jonathan Balcombe points out: ‘In light of their sometimes vastly different living circumstances and sensory capabilities, other species may experience some emotional states that we do not.’

Sentience – the capacity of an organism to feel – is fundamental to being alive. If human beings have souls, they must be more about sentience than consciousness. We are motivated far more by passion than by intellect – what we feel deeply is what drives us, for good and ill. In his book Pleasure: A Creative Approach to Life (1970), the late psychoanalyst Alexander Lowen meditated on these connections, proposing that ‘The soul of a man is in his body. Through his body a person is part of life and part of nature … If we are identified with our bodies, we have souls, for through our bodies we are identified with all creation.’ As long as we are alive – and therefore feeling – we are connected to one another and to the natural world. We are, in a word, ensouled.

Extraordinary examples of ensoulment among non-human animals abound. Ethologist Adriaan Kortlandt once observed a wild chimp in the Congo ‘gaze at a particularly beautiful sunset for a full 15 minutes, watching the changing colors’, forsaking his evening meal in the process. Elsewhere, African elephants belonging to the same family or group will greet one another after a separation with a loud chorus of rumbles and roars as they rush together, flapping their ears and spinning in circles.

Thanks to the internet, there’s a steady stream of examples of animals demonstrating compassion, from an ape saving a crow to a gorilla protecting a 3-year-old boy when he fell into her enclosure. A particularly striking case of animal gratitude occurred in 2005 off the California coast, where a female humpback whale was found entangled in nylon ropes used by fishermen. As recounted by Frans de Waal in The Age of Empathy: Nature’s Lessons for a Kinder Society (2009): ‘The ropes were digging into the blubber, leaving cuts. The only way to free the whale was to dive under the surface to cut away the ropes.’ The divers spent an hour at the task, an especially risky one given the sheer strength of the animal’s tail. ‘The most remarkable part came when the whale realised it was free. Instead of leaving the scene, she hung around. The huge animal swam in a large circle, carefully approaching every diver separately. She nuzzled one, then moved on to the next, until she had touched them all.’

Animals that express gratitude, play, contemplate nature, act to save a fellow creature, or react mournfully to the loss of family members or other close companions, are all, in my view, demonstrating aspects of connectedness. Such connectedness is the root of spirituality – with the capacity to feel and emote being central.

In the end, soul may be a profound matter of fellow feeling. The stronger the capability of a given species for fellow feeling, the more that species can be said to exhibit soulfulness. To view things in this way offers another important step in humanity’s progression towards understanding its place in creation – and to appreciate the inheritance we hold in common with other sentient beings on this increasingly small, restive, and fragile planet.