“Let’s start with mammals – a grouping which includes rats, bats, monkeys, manatees, lions, hippos, and of course humans too. I believe that all mammals are conscious. Of course, I don’t know this for sure, but I am pretty confident. This claim is not based on superficial similarity to humans, but on shared mechanisms. If you set aside raw brain size – which has more to do with body size than with anything else – mammalian brains are strikingly similar across species.”