Christopher asked:

This is a response to a question answered by Shaun Williamson that I asked about ‘intelligence/ consciousness and evolution’ In this answer, it was stated that ‘Being conscious means having sensory awareness of the world and to have sensory awareness of the world you need sense organs and a nervous system’. My question regarding this is does this mean that if you are blind you are only 4/5 or 80, conscious? Given that we have 5 senses and your assertion that sensory awareness of the world is needed in order to be conscious, it follows that there are levels of consciousness. Therefore if someone with 5 working senses would he have a higher level of consciousness than someone without 5. If this is so, then wouldn’t that also end the discussion about AI and other natural organisms having consciousness.

Answer by Craig Skinner

I think that, in this context, we should speak of varieties, rather than levels, of consciousness. And that it doesn’t end discussion about AI and other natural organisms.

Doctors routinely assess ‘level’ of consciousness, especially if brain damage is suspected, and typically class the patient’s conscious level as:

* normal (fully conscious)
* clouded
* stupor (unconscious but rousable)
* coma (unconscious and unrousable)

So a healthy blind person is typically fully conscious, while a dead-drunk man with perfect senses can be stuporose.

Clearly, a blind person’s consciousness is impoverished, but typically she enriches it by making much more of other senses (especially touch) than fully-abled people. Likewise deaf people learn to understand speech by sight (sign language) rather than by hearing. And those with anosmia are rarely connoisseurs of food (flavour depends on smell as much as taste). In short, sensory impairment leads to a different sort of consciousness.

As regards other animals, don’t confuse consciousness with intelligence. Some animals have much better vision than us – birds of prey spot a mouse in a field from hundreds of feet up, some birds display with (to us) drab grey feathers that are seen in colours we can’t imagine by their potential mates with vision extending to the ultra-violet. And echolocating bats presumably have conscious experiences we can’t imagine. So some animals have consciousness richer than ours in some respects. The distinctive feature of human consciousness is self-consciousness, of which only glimmerings seem apparent in some other animals.

As regards AI, yes, sensory input was ignored for decades as ‘good-old-fashioned AI’ strove to produce ever more elaborate algorithms for digital computers. But now, AI is focussing on units which have sensory input, act in the world, learn and develop with time as we do, and in due course I see no reason for these not to be conscious.


(a) is consciousness possible without sensory awareness, without a body at all say? Theists think so. Descartes thought so: he considered thought (reasoning, deciding, believing, willing etc) was confined to immaterial substance (res cogitans), so that God and angels think, but emotion has a bodily component (racing heart, sweating, faster breathing, whatever) so that animals have emotions, and humans, being an intermingling of the two substances, have both thought and emotions. I am inclined to think consciousness is necessarily embodied, whether carbon based, silicon based or whatever, but you must form your own view.

(b) would AI lack emotion? We are inclined to think only flesh and blood creatures can have real feeling, whereas androids like Mr Data, even aliens like Mr Spock, are strong on logic, lacking in feelings. I don’t think so. As Descartes held, emotions have a bodily component, specifically (we now know) chemicals such as adrenaline, testosterone or serotonin affecting brain function, and I don’t see why analogous hormonal/endocrine effects couldn’t be built in to suitably developed AI.


Answer by Shaun Williamson

No it doesn’t follow that there are different levels of consciousness only that there are different sorts of consciousness. Suppose your blind man is a super taster (ten percent of people are super tasters) then in some ways he is more conscious than me because I am not a super taster. So how would you access his percentage of consciousness now. Many birds have superior eyesight compared to humans. Does this mean they are more conscious than us. They certainly see more than us but perhaps they make less use of what they see.

The discussion about AI is a rather different discussion. Dogs like us have eyes so it is reasonable to think that they see. They also have ears so they must hear. Machines don’t have eyes or ears or brains because eyes and ears and brains are organic things that arise naturally. Like us dogs can be made unconscious by a blow to the head. So it is not clear what would be needed for us to describe a machine as conscious.

Wittgenstein said ‘Our languages contain the sum total of distinctions that men have found useful it to draw. So contrary to what most philosophers think (because philosophers fantasize about language and think language was made by God not by men) the question ‘Can a machine be conscious really reduces to the question ‘Will we ever find it useful to describe certain machines as conscious?’.