In 1967 British biologist and Nobel laureate Sir Peter Medawar famously characterized science as, in book title form, The Art of the Soluble. “Good scientists study the most important problems they think they can solve. It is, after all, their professional business to solve problems, not merely to grapple with them,” he wrote.

For millennia, the greatest minds of our species have grappled to gain purchase on the vertiginous ontological cliffs of three great mysteries—consciousness, free will and God—without ascending anywhere near the thin air of their peaks. Unlike other inscrutable problems, such as the structure of the atom, the molecular basis of replication and the causes of human violence, which have witnessed stunning advancements of enlightenment, these three seem to recede ever further away from understanding, even as we race ever faster to catch them in our scientific nets.

Are these “hard” problems, as philosopher David Chalmers characterized consciousness, or are they truly insoluble “mysterian” problems, as philosopher Owen Flanagan designated them (inspired by the 1960s rock group Question Mark and the Mysterians)? The “old mysterians” were dualists who believed in nonmaterial properties, such as the soul, that cannot be explained by natural processes. The “new mysterians,” Flanagan says, contend that consciousness can never be explained because of the limitations of human cognition. I contend that not only consciousness but also free will and God are mysterian problems—not because we are not yet smart enough to solve them but because they can never be solved, not even in principle, relating to how the concepts are conceived in language. Call those of us in this camp the “final mysterians.”

Consciousness. The hard problem of consciousness is represented by the qualitative experiences (qualia) of what it is like to be something. It is the first-person subjective experience of the world through the senses and brain of the organism. It is not possible to know what it is like to be a bat (in philosopher Thomas Nagel's famous thought experiment), because if you altered your brain and body from humanoid to batoid, you would just be a bat, not a human knowing what it feels like to be a bat. You would not be like the traveling salesman in Franz Kafka's 1915 novella The Metamorphosis, who awakens to discover he has been transformed into a giant insect but still has human thoughts. You would just be an arthropod. By definition, only I can know my first-person experience of being me, and the same is true for you, bats and bugs.

Free will. Few scientists dispute that we live in a deterministic universe in which all effects have causes (except in quantum mechanics, although this just adds an element of randomness to the system, not freedom). And yet we all act as if we have free will—that we make choices among options and retain certain degrees of freedom within constraining systems. Either we are all delusional, or else the problem is framed to be conceptually impenetrable. We are not inert blobs of matter bandied about the pinball machine of life by the paddles of nature's laws; we are active agents within the causal net of the universe, both determined by it and helping to determine it through our choices. That is the compatibilist position from whence volition and culpability emerge.

God. If the creator of the universe is supernatural—outside of space and time and nature's laws—then by definition, no natural science can discover God through any measurements made by natural instruments. By definition, this God is an unsolvable mystery. If God is part of the natural world or somehow reaches into our universe from outside of it to stir the particles (to, say, perform miracles like healing the sick), we should be able to quantify such providential acts. This God is scientifically soluble, but so far all claims of such measurements have yet to exceed statistical chance. In any case, God as a natural being who is just a whole lot smarter and more powerful than us is not what most people conceive of as deific.

Although these final mysteries may not be solvable by science, they are compelling concepts nonetheless, well deserving of our scrutiny if for no other reason than it may lead to a deeper understanding of our nature as sentient, volitional, spiritual beings.