I make no excuse for returning to the topic of consciousness. It’s a phenomenon that, apparently, everyone experiences, and almost certainly some animals experience it too. However, it is the ultimate in subjectiveness. No one except yourself knows how you experience consciousness.
It can’t currently be measured and we can only detect it by the behaviour of a person. The old chestnut of a comatose patient coming round with hovering relatives and medical staff is familiar to all. “He’s coming round!” says a person at the bedside as the patient’s eyes flicker and his muscles twitch.

This is not a reliable way of determining consciousness. People have surfaced from comas or anaesthetics and have reported that contrary to the physical evidence they were in fact conscious for at least some of the time when they were comatose. Also, deep brain scans have shown changes which may indicate that the patient was responding to question in that his brain patterns changed, which has led to a medical furore. There is disagreement as to whether or not the changes in the brain indicate that the patient was in fact conscious.
Definition of “Conscious”1.a. Characterized by or having an awareness of one’s environment and one’s own existence, sensations,and thoughts. See Synonyms at aware.
b. Mentally perceptive or alert; awake: The patient remained fully conscious after the local anesthetic was administered.2. Capable of thought, will, or perception: the development of conscious life on the planet.
The fact that consciousness is an objective phenomenon (so far as we can currently tell) means that we can only subjectively assess if it exists in a person. Even if a person behaves as if he or she were conscious, feeling pain, drinking beer, doing all the things that a conscious person would do, how does one know that this person is actually a conscious person? It is conceivable that what looks like a person is a sort of zombie, programmed to behave exactly like a conscious person would behave.

(These philosophical zombies are not like the usual cinematic concept of a zombie – they look like ordinary people, they have not died and revivified, bits do not fall off them, and they don’t have a hunger for brains. It’s a technical philosophical term).
The short answer is that there is currently no objective was to tell. Everyone except yourself might be a zombie. Erm, although I subjectively know that I am not, which might mean that I am the only conscious person in a world of zombies. It’s probably simplest to argue, that I am conscious, and I appear to be little different to everyone else, so it would be silly to argue that everyone else is a zombie. It’s much more likely that we are all subjectively conscious in our own heads.
Consciousness appears to be an aspect of the brain/mind. If parts of the brain are destroyed, or momentarily shocked by a blow, consciousness ceases and the person becomes unconscious. As above, though, it is conceivable that a person might not be able to move or respond, but still be conscious in the prison of their skull. It sounds like a particularly unpleasant fate.
Consciousness appears to be an emergent property of the brain/mind, because there does not appear to be a particular part of the brain that is related to consciousness as such. I think that it is fair to say this, though I haven’t delved into the subject much recently, though I do read things as I write these posts. In doing this I read an article on The Time website which hits many of the same high notes as I’ve hit here. It’s nice when I find an article that does that!

An emergent phenomenon is something like a family or a sports team or a termite nest. The emergent phenomenon is not implicit in individual members of the family or the sports team or the termite nest, but all the members make up a new entity which has an identity of its own.
Emergent phenomenon rely on the synergistic effect of all the members working in a concerted way to achieve more than a single individual can achieve by themselves. (Emergent phenomenon are not restricted to social interactions – water is wet, though an individual water molecule cannot really be considered to be wet in itself).

It follows that, just as the higher animals band together into families, bands and packs, which is an emergent phenomenon seen in humans societies, that the brains/minds of some animals are likely to experience the emergent phenomenon of consciousness, as they behave as if they do. It is highly unlikely that consciousness only evolved in one species, though of course it is possible.
Opponents of the idea that animals may exhibit consciousness suggest that we are anthropomorphising when we detect conscious behaviour in animals, and that they may be be zombies (in the philosophical sense of the word), and that the apparent consciousness is merely behaviours that are instinctive.

Of course, no one knows for sure if animals do experience consciousness or not. I rather feel that it is likely that they do, and the extent to which they do is determined by how sophisticated their minds and brains. Certainly, I feel it is unlikely that consciousness is controlled by a genetic on/off switch and that it evolved in animals in the same way as any other trait, that is gradually, and our near relatives on the genetic tree are to some extent at least conscious.
If this is so, then consciousness in animals other than ourselves inform ethics – we should treat animals as if they are conscious beings, as far as we can. I read a science fiction story once in which every being on the earth got a boost in brain function as a result of the earth leaving any area of space where a brake was put on brain function by some physical field or similar phenomenon.
The human race immediately became super-intelligent, and apes became at least as intelligent and conscious as we were. Also other animals, which we used as food sources became to some extent aware. As the story ended one of the characters was musing on this fact and suggested that maybe a religion of self-sacrifice could be given to these animals so that we could continue to eat them. I’d suspect that, more likely, the human race would become vegetarian! Or possibly, as suggested in the story, we would employ the apes to do the dirty work for us.
