We do not know in detail how human consciousness arose, and we only have direct evidence of our own consciousness. But it is common sense to assume that most normally behaving people are conscious to some degree, and that consciousness is a result of biological processes of the body, and its organs, even though we cannot see it directly, the way we appear to see our own consciousness.
Assumptions about the level of consciousness of other people affect modern society at a deep level. A conscious mind is thought to have free will, to a greater degree than simpler animals or machines do. In criminal law, a person can only be judged on the actions they take consciously, but not while for example sleepwalking or hallucinating.
The old metaphor is that consciousness is to the body like a pilot is to the ship. The pilot of a ship needs information and feedback to do his job, but he does not have direct access to it. Instead, he gets his information secondhand from the lookouts, and the various instruments for measuring speed with knots, the compass, and elsewhere. The pilot also does not row the oars himself, or stoke the engines, he just sends instructions below and assumes they will be carried out. The pilot does nothing directly, but all vital information must flow timely through him. Neither is steersman the same role as the captain; piloting work means reacting to the currents and the winds as they happen, not long-term goal-setting or strategic planning.
[Note: The old greek word for pilot is kubernetes, which is the etymological root word for both ‘cyber-‘ and ‘govern-‘ words.]
Piloting a ship is not always hectic, at times the ship can be safely moored at harbour, or the sailing can be so smooth that the pilot can take a nap. But when the ship is at strange seas, risking greatest danger from outside forces, pilot-consciousness kicks in fully, alerting all lookouts and powering the engines to full reserve power, ready to react to whatever happens. When the outside forces show their full might, the pilot is more worried about the ship surviving the next wave, than getting to the destination on time.
The state or level of consciousness is often associated with some feelings of anticipation, alertness, even worry or anxiety; such feelings can even prevent dialing down the level of consciousness to restful sleep, and thereby cause more stress the next day. Pain can only be felt when conscious, hence the cliché of pinching yourself to check if you are dreaming or not. Pathos [the root word for ‘-pathy’ words, like empathy or psychopathy], in all its meanings, is a strong catalyst to rouse consciousness. Only humans are thought to be capable of becoming truly conscious of their own mortality, the conscious mind thus becoming aware of the limits of its own existence.
When the pilot takes over and commandeers a vehicle, the flexibility of consciousness allows him to extend his notion of self to include the vessel. For example, an experienced driver can experience his car sliding on a slick patch of road as a tactile sensation, as if a part of himself was touching the road, and not the tires. In the same way, human consciousness naturally tends to identify itself as the whole individual. Sigmund Freud named the normal conscious part of the mind ‘ego’, which is ‘self’ in latin. His key observation was that the mind is much more than the ego, and that true self-knowledge requires careful study, which he called psycho-analysis.
Introspection is an imperfect tool for studying one’s own mind, due to the many literal and metaphorical blind spots involved. The ego is very capable of fooling itself. This is why it is not considered safe to try doing psycho-analysis by yourself, you should have guidance from someone who has gone through the process. Same applies for some methods of controlling consciousness through meditation.
There are methods of self-discovery that are less dangerous, such as the various personality tests. To extend the metaphor, different pilots have their own favorite places on the ‘bridge’, their habitual ways of operating the ship, or specific feelings associated with its operations. Your ‘center’ may not be in the same place as someone else’s. For example, a procrastinator waits until the last possible moment to make a decision; it could be that only the imminence and finality of a deadline makes their choices feel ‘right’ or ‘real’ enough to commit to. Another example is risk-seeking/aversion: some people only feel alive when in some amount of danger; others do their utmost to pass risks and responsibilities to other people.
Most pilots become habituated to a specific level of stress when operating the self-ship, and cannot function well without it; the types and levels of preferred stress can vary much between individuals. Too much stress however can break the pilot and damage the ship. This is also variable between individuals. Hans Eysenck theorized that sensitivity of an individual to be easily traumatized is correlated to intraversion, or that extraversion could be even redefined in terms of tough-mindedness; but there are other models as well, such as psychological ‘resilience‘, which supposedly can be trained as a ‘life skill’.
Habits are also something that can be consciously trained, and paying attention to our own habits is very healthy in the long run. Consciousness is tuned to fairly limited range of timescales; changes that happen too fast or too slowly do not enter consciousness. Daily habits creep slowly, and without photographs it would be hard to believe how much we change over time. Almost all of the atoms and molecules in our bodies are swapped to new ones every few years, yet our sense of identity remains continuous.
Heraclitus says that “a man’s character is his destiny”, and to know thyself means knowing your weaknesses, as well as strengths. Multitasking is a typical weakness that the pilot often confuses for a strength. Consciousness appears to be the stage where all experience terminates, but the real multitasking happens at the edges; the decision of which of the competing stimuli enter consciousness is never a completely conscious decision. The same applies to commands outgoing, unfortunately. Completeness of control can be an illusion, a form of magical thinking.
Many philosophers have also been fascinated with the true nature of the biggest ‘blind spot’ of consciousness: consciousness itself. There have been various efforts to formalize the ‘contents’ of consciousness, or to model consciousness in terms of ‘properties’ that some entity may or may not ‘have’. There are inherent limitations with these approaches, they should be taken in the original context of phaneroscopy, without drawing any metaphysical conclusions from them.
Not many deny that life, and consciousness, is a process, and human viewpoint is one of moving inexorably forward through Time. The ‘contents’ of consciousness form an unstoppable stream, moving in relation to our self-identity. It seems to us that our mind is anchored to something unmoving and unchanging, with the world changing around it. Yet we identify no specific ‘qualia’ for change or motion, or atomic perceptions of time passing. [There are some thresholds to when we begin recognizing a rhythm, though.]
The true nature of subjective experience may be a ‘hard problem’, but no harder than explaining the true nature of Time. The human condition is to flow from an unchangeable past, inexorably and continuously forward, towards an unknown future, and to only ever be able to act in the present. The pilot role is necessary exactly because the flow that powers all flows cannot be stopped, it can only be navigated.