Dictionary definitions such as this one often seem to use the terms sentience, awareness, and consciousness as if they are synonymous with each other. Is this really the case? If not, how do they differ? Some books suggest that sentience and awareness are simply facets of the larger concept of consciousness.
These are all terms that one frequently reads in texts on Cognitive Science. I will try to find some exemplary definitions:
Consciousness: Many philosophers have argued that consciousness is a unitary concept that is understood intuitively by the majority of people in spite of the difficulty in defining it. Others, though, have argued that the level of disagreement about the meaning of the word indicates that it either means different things to different people, or else is an umbrella term encompassing a variety of distinct meanings with no simple element in common (Wikipedia). You should check the SEP article for there is a lot more to say about consciousness than one of us could actually summarise here.
Sentience is the ability to feel, perceive, or be conscious, or to have subjective experiences. Eighteenth century philosophers used the concept to distinguish the ability to think ("reason") from the ability to feel ("sentience"). In modern western philosophy, sentience is the ability to have sensations or experiences (described by some thinkers as "qualia"). Sentience is a minimalistic way of defining "consciousness", which is otherwise commonly used to collectively describe sentience plus other characteristics of the mind. (Wikipedia)
Awareness is the state or ability to perceive, to feel, or to be conscious of events, objects, or sensory patterns. In this level of consciousness, sense data can be confirmed by an observer without necessarily implying understanding. More broadly, it is the state or quality of being aware of something. In biological psychology, awareness is defined as a human's or an animal's perception and cognitive reaction to a condition or event. (Wikipedia)
If I'm not mistaken it's halfway safe to say that awareness and sentience are levels or subclasses of the consciousness. Awareness is mainly the physical act of perceiving, while sentience is a subjective way of actually being affected. Consciousness then is used in many different meanings, but often as a umbrella term for several faculties. Hope I could help, check the links for more information.
I have been recently reviewing the question of consciousness vs. awareness and it seems to me that consciousness includes an element of knowing something that is in awareness while awareness can be sub-conscious as demonstrated by selectively becoming conscious of specific stimuli as they arise which would not be possible without sensory awareness. Based on this consciousness requires awareness but awareness does not require consciousness. Most of what we are aware of is not conscious and usually never will be and some of it cannot be conscious, at least normally, such as sensory processing. Consciousness is a known model of some of what is in awareness which itself is a representation of the output of various forms of unconscious processing. For reference see Psychology: The Study of Human Behaviour by Robert Ornstein an Laura Carstensen (1991). Sentience implies the capability of consciousness or highly responsive awareness.
Drawing on existing contributions, I wonder if introducing the concept of interoperability might lend clarity and a useful organizing stability to the discussion of these interrelated terms? To wit: Consider human development (both of an individual subject and of the specie in toto) and the utility of the underlying characteristics embodied by each of these three terms [probably a separate discussion in its own right].
SENTIENCE seems to carry and connote characteristics which satisfy conditions of minimal interoperability between the individual and a necessary set of others. Developmentally, for example, an otherwise physically nourished individual possess and makes individually beneficial use of what is sensed in the absence of a formal vocabulary and extensive societal protocal for information interchange. One acquires somatisensory input, such as it is and assigns highly personalized, idiosyncratic and subjective meaning to the input.
The need to express or the potential utility derived from sharing and exchanging of such assigned meaning drives the process of abstraction yielding vocabulary of both physical utterance and action that demands organized AWARENESS within the individual's own mentation and that of other individuals in the relavent social environment. That is to say, a broader plane of interoperability.
Similarly, faced with a more expansive [read, "multicultural"] sphere of potential interchange, abstraction of a more complex nature is required. Introspection and imaginative extrospection are both requied to achieve high degrees of interoperability across boundaries of sophistocated, highly evolved and possibly ridgid systems of social interchange. Not an impossible objective (witness the UN, the OAS, the EEU) but one which demands an individually optimized abstraction of the full range of human experience integrated and shared among a spectum of multiple and distinct social systems. Such a state, IMHO, would qualify as a "CONSCIENCE". A brightly robust, internally stable CONSCIOUS awareness of one's own sense of values & assigned meaning as derived through abstract thought processes that are capable of adapting to and integrating with functionally similar processes in a wide range of inhabitants (i.e., across multiple species of living participants) in the relevant ecosystem.
The threshhold CAPACITY of the individual for achieving so developed a state of interoperability, predicated as it is on both sentience and awaress is, I submit, reasonably termed CONSCIOUSNESS.
We all use words to communicate, hopefully with a standard "unpacking" from symbols to meaning. However words should not be used as a restriction of what can or cannot exist in the mind.
Awareness to me, is what your body, sense organs know from your own viewpoint. Consciousness allows an input of that awareness in addition to other people's awareness. If you made a game where a monster made decisions based upon his/her own threat system, it would be acting according to its own awareness. However when it considers the threat system of its own threats, it may make decisions otherwise. In other words, it may have a chance of doubting its own awareness in favor of another awareness, or in the case of partial blindness, increase its own vision beyond what the eyes/ears etc can see. Consciousness is far more complicated than simply processing the outside world, it is a merging of multiple words into one. (Assuming the merge does not have contradictions, one is seeing beyond what one can see and know directly. And in the case of contradictions, this leads to the capacity of disagreement.) Also to note, a conscious object is formed, as a context of learning and is critical to rapid improvement. A conscious object can contain the spatial graph of many three dimensional spaces, forming a kind of invisible (non sensory) 4 dimensional space. One other thing a conscious object can do, is project one's position into a different one, allowing one to imagine what the sensory experience would be if one were to occupy that position. Eventually the conscious makes decisions in a three dimensional space, but this is a kind of quaternion map back down to three dimensions, or a complex number mapping onto a real number (in analogy).
Another thing about consciousness is that it appears to allow the input of thought streams of other people (communication) into one's own (communication object) bringing about the concept of symbolism. Why would we have symbols if there wasn't another mind to receive them? Symbols appear to play a conscious role in thought generation outside one's current awareness.
Also note, sometimes when we think of emotional pain, we think of social rejection, possible through a conscious view. The more we understand how the brain handles conscious problems, the more we can figure out what we call a "bad conscious" which can increase fear exponentially higher than simple awareness of a threat, aka someone else knows you are afraid at the same time you are afraid. Therefore I think that my fear, related to my awareness, is heightened by others fear, and is experienced as a different kind of thing in the mind. That is to be conscious comes with both its great strengths and menacing daemons. We can also have empathy for other people's awareness.
Sentience however to me, is the ability to take in not the thoughts of another (could be wrong) but the thinking of another (could be even wronger) and is far more complicated. Instead of thoughts coming in from different people, we see thought machines instead. We see the conscious of another, that is, the threat is not person A, but person A + B + C + D if an event were to occur, social grouping up on a person for a thought. The conscious can form a social thought police. Sentience however leads to war.
The terminators do not see the human's awareness, but their conscious and deem the human race incapable of the necessary brain power to form sentiance, that is the terminators calculate a cruel salvation for man-kind.
Another way to think of sentiance is again by refelcting on consciousness, consciousness allows us to override our own awareness, if another's awareness takes priority, aka our pain because another needs us - because the pain for another is calculated as worse pain, we may sacrifice our selves for another. Sentience on the other hand, can override our conscious, because the solution to the conscious problem is deemed poor, it seem extremely cruel. Awareness bubbles up to conscious, and a conscious problem bubbles up to sentience. Sentience solves the moral dilemma of the conscious, but a person who has a bad "sentience" can have a whole new tier of emotional pain, that of evaluating the consciousness of a group and deeming the entire 4 dimensional space as a poor solution to a perceived larger sentient problem. Actually leaders usually must be sentient, because they seem to override people's conscious all the time, and can be seen as even more evil, yet trying to make a larger sensation work. That is they will fire you, despite your conscious of your family because the whole company is suffering.
And yes there are layers beyond that, but somehow it is about how we make decisions. A general rule is that when there is more than one of something, we need description for selection, unless nature decides for us.
One such other layer, which I think is a diplomatic layer, increases the mind to the point where we can see something like a world war, and realize how destructive it is. It isn't enough to say that someone was hurt (awareness of another in our conscious layer) but the way it also hurts other people, including the person hurting the other (awareness of the conscious results - sentience, we feel somehow about it. More complicated thinking) But the entire war as hurting a larger social fabric, possibly even the world itself. In other words to be diplomatic is a something more complicated than sentience. Not everyone can be diplomatic. A diplomat, might see the general problems in an organization and realize that while it makes sense to fire a man connected to his consciousness, the sentience of the company is connected to the social fabric and produces more negative problems for the company later on. However it has to be going through even more complicated processing.)
I would say that the solution of the terminators was not very diplomatic to say the least.
I think that it is important not to conflate these terms - see my question about this. And it would be useful to have a spectrum of terms in this area. So it seems that consciousness seems to imply self-consciousness. Awareness seems to the ability to detect and respond to stimuli. So detection of salinity in a single-celled marine organism would be awareness. Sentience seems to between these definitions, so an improvement on mere awareness but less than self-consciousness. So awareness is demonstrated by amoebae, sentience by dogs, and consciousness by humans - taking the liberty that it exists! In this context, can non-living things have awareness? I suggest that quantum entanglement suggests awareness in entangled particles.