Reading a medical dictionary’s definition of human consciousness, I had to ask myself with each bullet item what it was about that definition that was different from what animals have. In some cases I was forced to concede that animals have, to some degree or another, the characteristics cited in the definition. After contemplating the definitions, I tried to find something that really demonstrated that human consciousness was unique amongst life on earth.
First (not necessarily foremost), human consciousness is the unique ability to anticipate events and consequences and to plan our lives. The phrase "subjective awareness" (as used in the dictionary definition cited above) perhaps best defines the separation between humans and other life forms on earth. We have the ability to decide what is important and discard the less important whereas, in general, animals tend to react to any stimuli regardless of its importance. We understand and can differentiate between perceived, real, and non- threat. (There is no single authoritative definition of "subjective awareness." One college article said it is "what a person chooses to believe." If true, this also demonstrates the separation between human and beast. Animals do not "choose [what] to believe," rather they react to sensory inputs.)
Human consciousness is also what defines our ability to reason, hypothesize, imagine potential and create. Whether that creation be furniture or art, it is something that doesn't exist naturally. Some may argue that such is not creation, however I am not using the term in the same sense that the Bible speaks of God's creating things. However, it was by our use of cognitive reasoning, ability to see potential, and then to use skills through both individual and collective experience that gives us the ability to both "create" and expand on that for improvements.
Finally, for those who believe in God, human consciousness is the ability to grasp the unseen -- namely that intelligence superior to ours is what made us. Granted, atheists and agnostics are humans the same as believers are humans and their rejection of a creator does not lessen their humanity. However, with animals the concept of superiority stops with the visible. They have no consciousness of a God, gods, or whatever. They do not worship, they do not try to contemplate and understand the cosmos, nor even their own existence. However, mankind, even some atheists, have never stopped looking for a reason and understanding of why we are here.
In short then, human ability to anticipate, to plan (individually and collectively), to imagine; to improve our lot; and to worship are all unique features of human consciousness.
But now comes the big question -- where did this awareness, this cognition come from? The answer to that is not something atheists can adequately answer with any degree of satisfaction. To brush it off as a quirk of evolution demonstrates an air of arrogance like a professor that really doesn’t know the answer so he makes something up and then emphatically claim that his position is correct because of his education. However, those believing in God, especially those accepting the Bible, readily appreciate the value of knowing that humans were made in God’s image. Part of that “image” is the cognitive powers that no other creation (except angels) is mentioned as having (nor has any other earthly creature demonstrated). (Obviously the word “image” here cannot mean the compositional characteristics. God is a spirit being. Today, with our knowledge of science, we might more readily describe him as an intelligent energy life-force of some sort. Man, on the other hand is physical. So we must look to other characteristics, such as those already mentioned, in order to make sense of what the Bible is teaching.)
(The Bible teaches that God’s four main attributes are love, justice, wisdom and power. These also are demonstrated by mankind. While animals may to some degree demonstrate power it is not only power as in strength that the Bible is speaking of. Also, animals do care for their young and herd, however, the love humans express is usually considered a higher degree of cognition.)
It is my personal feelings that the very reason science cannot agree on how to correctly and accurately define consciousness is that it rejects the very foundation that we are made in God’s image. Without that ground-floor belief, nothing else makes sense. There really is no reason, evolutionary or otherwise, for man to have this ability apart from it being an endowment by a loving creator.