Some are very critical of some uses of the word consciousness.
"The field is replete with weasel words and unfortunately one of those is consciousness," says Prof Stevan Harnad of Quebec University.
"It is a word that is confidently used by a lot of people, but they all mean something different, and so it is not clear at all what it means."
He says that a better, less weasley, word is "sentience", which is more tightly defined as the capacity to feel. "To feel everything, a pinch, to see the colour red, to feel tired and hungry, those are all things you feel," says Prof Harnad.
Others who have been instinctively sceptical of the idea of animals being conscious say that the new broader interpretation of what it means to be conscious makes a difference.
Dr Monique Udell, from Oregon State University, says she comes from a behaviourist background.
"If we look at distinct behaviours, for example what species can recognise themselves in a mirror, how many can plan ahead or are able to remember things that happened in the past, we are able to test these questions with experimentation and observation and draw more accurate conclusions based on data," she says.
"And if we are going to define consciousness as a sum of measurable behaviours, then animals that have succeeded in these particular tasks can be said to have something that we choose to call consciousness."
This is a much narrower definition of consciousness than the new group is promoting, but a respectful clash of ideas is what science is all about, according to Dr Udell.
"Having people who take ideas with a grain of salt and cast a critical eye is important because if we don’t come at these questions in different ways, then it is going to be harder to progress."
But what next? Some say far more animals need to be studied for the possibility of consciousness than is currently the case.
"Right now, most of the science is done on humans and monkeys and we are making the job much harder than it needs to be because we are not learning about consciousness in its most basic form," says Kristin Andrews, a professor of philosophy specialising in animal minds at York university in Toronto.
Prof Andrews and many others believe that research on humans and monkeys is the study of higher level consciousness – exhibited in the ability to communicate and feel complex emotions – whereas an octopus or snake may also have a more basic level of consciousness that we are ignoring by not investigating it.
Prof Andrews was among the prime movers of the New York Declaration on Animal Consciousness, external signed earlier this year, which has so far been signed by 286 researchers.
The short four paragraph declaration states that it is “irresponsible” to ignore the possibility of animal consciousness.
"We should consider welfare risks and use the evidence to inform our responses to these risks," it says.
Chris Magee is from Understanding Animal Research, a UK body backed by research organisations and companies that undertake animal experiments.
He says animals already are assumed to be conscious when it comes to whether to conduct experiments on them and says UK regulations require that experiments should be conducted only if the benefits to medical research outweigh the suffering caused.
"There is enough evidence for us to have a precautionary approach," he says.
But there is also a lot we don’t know, including about decapod crustaceans such as crabs, lobsters, crayfish, and shrimp.
"We don’t know very much about their lived experience, or even basic things like the point at which they die.
"And this is important because we need to set rules to protect them either in the lab or in the wild."
A government review led by Prof Birch in 2021, external assessed 300 scientific studies on the sentience of decapods and Cephalopods, which include octopus, squid, and cuttlefish.
Prof Birch’s team found that there was strong evidence that these creatures were sentient in that they could experience feelings of pain, pleasure, thirst, hunger, warmth, joy, comfort and excitement. The conclusions led to the government including these creatures into its Animal Welfare (Sentience) Act in 2022.
"Issues related to octopus and crab welfare have been neglected," says Prof Birch.
"The emerging science should encourage society to take these issues a bit more seriously."
There are millions of different types of animals and precious little research has been carried out on how they experience the world. We know a bit about bees and other researchers have shown indications of conscious behaviour in co*ckroaches and even fruit flies but there are so many other experiments to be done involving so many other animals.
It is a field of study that the modern-day heretics who have signed the New York Declaration claim has been neglected, even ridiculed. Their approach, to say the unsayable and risk sanction is nothing new.
Around the same time that Rene Descartes was saying "I think therefore I am", the Catholic church found the Italian astronomer Galileo Galilei "vehemently suspect of heresy" for suggesting that the Earth was not the centre of the Universe.
It was a shift in thinking that opened our eyes to a truer, richer picture of the Universe and our place in it.
Shifting ourselves from the centre of the Universe a second time may well do the same for our understanding of ourselves as well as the other living things with whom we share the planet.
