Consciousness in humans easily defined, and pretty well understood. Consciousness in animals uses similar definitions, but describes consciousness in animals by degree compared to humans. This refelects the evolution in animals, which parallels the evolution of the complexity of the brain.
From: Animal consciousness - Wikipedia
Animal consciousness, or animal awareness, is the quality or state of self-awareness within an animal, or of being aware of an external object or something within itself.[2][3] In humans, consciousness has been defined as: sentience, awareness, subjectivity, qualia, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind.[4] Despite the difficulty in definition, many philosophers believe there is a broadly shared underlying intuition about what consciousness is.[5]
The topic of animal consciousness is beset with a number of difficulties. It poses the problem of other minds in an especially severe form because animals, lacking the ability to use human language (except certain birds such as grey parrots), cannot tell us about their experiences.[6] Also, it is difficult to reason objectively about the question, because a denial that an animal is conscious is often taken to imply that it does not feel, its life has no value, and that harming it is not morally wrong. The 17th-century French philosopher René Descartes, for example, has sometimes been blamed for mistreatment of animals because he argued that only humans are conscious.[7]
Philosophers who consider subjective experience the essence of consciousness also generally believe, as a correlate, that the existence and nature of animal consciousness can never rigorously be known. The American philosopher Thomas Nagelspelled out this point of view in an influential essay titled What Is it Like to Be a Bat?. He said that an organism is conscious "if and only if there is something that it is like to be that organism—something it is like for the organism"; and he argued that no matter how much we know about an animal's brain and behavior, we can never really put ourselves into the mind of the animal and experience its world in the way it does itself.[8]Other thinkers, such as the cognitive scientist Douglas Hofstadter, dismiss this argument as incoherent.[9] Several psychologists and ethologists have argued for the existence of animal consciousness by describing a range of behaviors that appear to show animals holding beliefs about things they cannot directly perceive—Donald Griffin's 2001 book Animal Minds reviews a substantial portion of the evidence.[10]
Animal consciousness has been actively researched for over one hundred years.[11] In 1927 the American functional psychologist Harvey Carr argued that any valid measure or understanding of awareness in animals depends on "an accurate and complete knowledge of its essential conditions in man".[12] A more recent review concluded in 1985 that "the best approach is to use experiment (especially psychophysics) and observation to trace the dawning and ontogeny of self-consciousness, perception, communication, intention, beliefs, and reflection in normal human fetuses, infants, and children".[11] In 2012, a group of neuroscientists signed the Cambridge Declaration on Consciousness, which "unequivocally" asserted that "humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neural substrates."
Advanced forms of consciousness by degree reflected in evolution can be found many animals in particularly in our relatives the primates.
Other non-mammal animals such cehlapods:
From: Animal consciousness - Wikipedia
Cephalopod intelligence has an important comparative aspect in the understanding of intelligence because it relies on a nervous system fundamentally different from that of vertebrates.[1] The cephalopod class of molluscs, particularly the Coleoidea subclass (cuttlefish, squid, octopuses), are thought to be the most intelligent invertebrates and an important example of advanced cognitive evolution in animals.
The scope of cephalopod intelligence is controversial, complicated by the elusive nature and esoteric thought processes of these creatures. In spite of this, the existence of impressive spatial learning capacity, navigational abilities, and predatory techniques in cephalopods is widely acknowledged.[2].
Nagel's bat has always been puzzling to me. Why would *we* need to experience what the bat does to know what it is like to be a bat in most particulars?
This is another of those claims that there is a 'hard problem' of consciousness, which, truthfully, I just don't accept. If we are able to correlate brain activity to conscious experiences in mutually predicable ways, how is that *not* an explanation of consciousness and the mind? And we just apply that same technique to other species.