The case that the brain makes it
The default position in neuroscience is physicalism: consciousness arises from the organized activity of the brain, much as digestion arises from the gut. The evidence is substantial. Damage a specific brain region and a specific part of experience can vanish, from color vision to the ability to recognize faces. Anesthetics reliably switch experience off and on by acting on neural tissue. As the brain matures, so does the mind. Everywhere we look, changing the brain changes the experience, in lawful, repeatable ways.
On this view, asking where consciousness 'comes from' is like asking where a whirlpool comes from: it is what certain complex processes do when arranged the right way. The open task, then, is to find which arrangements matter and why. That is hard, but it is ordinary science.
Why some take consciousness as basic
The reason the question stays open is the explanatory gap: no one has shown how mere physical mechanism could add up to felt experience. That stubborn gap motivates bolder options. Panpsychism, defended today by philosophers such as Philip Goff and Galen Strawson, proposes that experience, in some minimal form, is a basic feature of matter itself, present in simple form even in fundamental particles and combining into the rich consciousness of brains. It is an old idea, taken seriously again because it promises to close the gap by not opening it in the first place.
A related family, Russellian monism, suggests physics describes only what matter does, not what it is, and that its intrinsic nature may be experiential. Giulio Tononi's Integrated Information Theory, a leading scientific model, points in a similar direction: it locates consciousness wherever a system integrates information in the right way, which need not be limited to brains. At the far end stands idealism, the view that mind is the ground floor and the physical world a structure within it. None of these is fringe superstition; each is a live attempt to solve a real problem.
How we might decide
Right now the evidence underdetermines the answer. The tight brain-experience correlations are fully consistent with the brain producing consciousness, and also with the brain shaping and filtering a consciousness that is more basic. Correlation alone cannot tell producing from expressing.
There are paths forward. Thinkers in the tradition of Alfred North Whitehead's process philosophy argue that treating experience as fundamental may make nature more intelligible, not less. Scientific theories like Integrated Information Theory make testable predictions about which physical systems should be conscious, and experiments are beginning to probe them. Progress will likely come from theories precise enough to be proven wrong. For now, the intellectually honest answer is that whether consciousness is built by the brain or built into the world remains genuinely unsettled, and it is one of the most interesting unsettled questions there is.