One ought to study how one ought to live.

How ought one live? A question at once esoteric yet personal, metaphysical yet immediate. Perhaps one should follow a path oriented towards the pursuit of knowledge and wisdom. Perhaps one should follow a path of fierce involvement in the world’s affairs. Perhaps one should live out an Epicurean hedonism, a life oriented towards the pursuit of long-term personal well-being. Perhaps one should live out a Millian altruism, a life oriented towards the pursuit of collective well-being.

Perhaps one should live a life catering to the quantifiable demands of financial markets, and so use them as a compass that points towards “generated value.” Perhaps one should live a life catering to the legible demands of reputation markets, and so adopt society’s emergent morality as one’s own. Perhaps one should live a life catering to the visceral demands of evolutionary adaptations, and so employ pleasure and pain as ultimate custodians of good and evil.

Perhaps there is no such thing as the right way to live, a view which thrives along with the combinatorial fetish of postmodernism, yet which finds its most vivid expression in Nietzsche. His works are almost mocking: “Beyond Good and Evil,” or “The Genealogy of Morals.” He claims, through the mouthpiece of Zarathustra, that God is dead—in the broader sense of there being no higher purpose, no values worth aspiring to, no virtues worth cultivating.

But how could one have come to know that? On what grounds could he be making these claims about the nature of this intangible object that is morality? While at that, on what grounds have Epicurus, Mill, and countless others ventured claims about the nature of this metaphysical structure? Beyond crude faith, on what grounds can we evaluate theories about metaphysical objects, weigh them against each other, and orient ourselves towards theories that are most in accord with their objects?

The home of ever more appropriate theories is science. However, science excels as a means of acquiring knowledge about tangible, concrete phenomena embedded in the same causal domain as us. What lab equipment could possibly intervene on morality? On what sensors could morality possibly leave its mark? Granted, one can study entities that themselves engage with these objects, but could one accomplish contact directly?

The home of systematic inquiry into abstract objects is mathematics. However, it is not the case that mathematics is not based on faith. The edifice is typically framed as foundationalist, the naked axioms bearing all its weight. Pledge allegiance to Euclid’s last axiom, and be granted cognitive ergonomics. Break your vow, and be forced to deal with Lovecraftian horrors. That said, mathematics enables proof, helping establish the validity of inferences between statements independently of the truthfulness of the statements involved. Mathematics excels at epistemological plumbing, setting up a network of abstract pipes that propagate truth, despite not accounting for it. Yet, the pipes themselves rely on axioms burrowed deep in mathematical logic and proof theory.

Unsatisfied with the empirical and the theoretical, we explore the conceptual. On one hand, metaphysics is concerned with the study of objects that appear to transcend the physical (e.g., prime numbers, human rights, beauty). On the other hand, epistemology is concerned with the study of knowledge and means of knowing (e.g., observation, testimony, memory). Combining the two, epistemology of metaphysics concerns itself with the means of gaining knowledge about intangible objects in particular.

More concretely, given arguments in support of different views on the nature of morality, epistemology of metaphysics might provide means of weighing them against each other. For instance, one theory might be simpler, and so might get ahead on these grounds. Alternatively, one theory might require fewer resources to defend. Of course, this begs the question: On what grounds can we establish the grounds on which we can compare theories about intangible objects? Knowledge and truth seem to be intangible themselves, so epistemology of metaphysics necessarily makes itself one of its objects of study. Theories about weighing metaphysical theories should reflexively apply to themselves, as theories are also abstract structures. How simple is Occam’s razor? How defensible is identifying truth with defensibility?

Consider again the opening question: How ought one live? There is no consensus. There is only moral uncertainty to be dealt with, and active inquiry into how to properly account for it. However, if there is such a thing as how one ought to live (e.g., promoting the well-being of others, cultivating wisdom, standing up for principles), then one ought to learn, study, seek the true nature of this intangible object that is morality, in order to be able to effectively incorporate its contents into one’s life. In other words, one ought to actively strive to reduce moral uncertainty—potentially by using machines—not only cope with it in its current form. And if there is no such thing, if the very construct of morality is vacuous, we might as well know for almost sure. One ought to know how one ought to live in order to live it out, or at least strive to know better.