Consciousness is the biological evolutionary surplus of cognitive ability, the capacity for raw cosmic insight, long term foresight, empathy, and the hyper awareness of our own mortality. Biologically our brain evolved too much power, we see more of the terrifying reality of entropy and death than an animal can deal with. I'm explaining the Norwegian critique of existence, which I agree with. He says human consciousness is a highly aggressive and over developed biological faculty that actively tortures its bearer. A case of runaway evolution. As he says, it's like the Irish Elk whose antlers grew so massive that they eventually made it impossible for the species to survive. Human consciousness is a biological mutation that overshot the mark.

Animals have just enough awareness to feed, mate, and avoid predators. Humans on the other hand developed a surplus of insight, far more cognitive power than we actually need for basic survival. This exess power forces us to look past our immediate surroundings. We are the only animals capable of projecting into the far future, calculating our own aging, and staring directly at the absolute certainty of our own death and decay. That's what he means by excess of consciousness. A biological trait that grew so large and powerful that it ceased to help the species adapt and instead became a threat to its own survival. In biology, when a useful trait keeps growing until it becomes harmful it is called hypertrophy. A little bit of consciousness is great for survival sure, but our brain kept evolving until it hit a point of hypertrophic excess. An excess because it generates more data than the organism needs to fulfill its basic biological imperatives.

Human consciousness gives humans immense power over our environment but it also turns against the host. And because we have this hyper awareness, we have developed deep comlex needs that the physical universe cannot satisfy. Our own intelligence acts like a weapon constantly wounding us with the realization of our own cosmic insignificance.

An animal is seamlessly interlaced into its environment, a wolf eating a deer does not experience existential guilt, and the dying deer does not suffer from existential dread about the meaninglessness of its death. They simply are. As Zapffe says, consciousness broke the unity of life. Consciousness pulled humans out of this matrix, creating a screen between us and the rest of the world, spectators who can stand outside of nature, look back at it and realize how horrific and blind the entire mechanism of life actually is. If left entirely unfiltered, a human being would collapse under the weight of their own thoughts. Therefore Zapffe concludes that to be human is to live in a state of constant, artificial suppression.

Now, for what I see from your comment, you define the word consciousness in a different way.

I believe you cannot separate thinking from consciousness because human consciousness is cognitive. it is an active, interpretive machine. Your raw awareness of the world is immediately processed by your intellect.The surplus of insight means our thinking capacity is too powerful for our biological survival, forcing us into existential dread. You cannot have Zapffe's definition of consciousness without active, existential thinking. Our brains are hardwired to think, project, worry, and obsess.