A central question for moral epistemology is how our moral beliefs are justified. In his Foundations of Bioethics, Hugo Tristram Engelhardt, Jr. argues that modern secular philosophy fails to provide a justification for moral belief. Despite this failure, which he equates with the failure of the "Enlightenment project," Engelhardt claims that we can peacefully collaborate by respecting one another's ability to agree or give permission.

In this essay, I respond to Engelhardt's critique of secular philosophy and his proposal for secular morality on the basis of permission. I compare Engelhardt's work with that of Alasdair MacIntyre, Harry G. Frankfurt, Gilbert Harman, David Lewis, and Jeffrey Stout on related questions. Engelhardt's proposal doesn't give us the "content-less" morality he claims it does. Far from being a purely formal concept, his notion of permission relies directly on many shared assumptions, particularly about the nature of freedom. Engelhardt actually describes a convention of morality that closely resembles our own current conventions of behavior toward strangers. Engelhardt's skeptical attack on secular moral philosophy is ineffective because it assumes a flawed concept of justification. A more robust kind of justification, built on Harman's conservatism, resists Engelhardt's skepticism. Moral philosophy isn't incapable of providing justification for our moral beliefs.

Justification is a process of fitting our beliefs together to reach reflective equilibrium. It relies on shared conventions of thought and action that are elements of our culture. It doesn't rely on a special foundation of unimpeachable belief, but takes account of all our relevant beliefs. Justification isn't just a matter of what we think but of how we think. When we say our beliefs are justified, we mean that until proven otherwise, we've gathered our beliefs properly and we think we're right. Justification isn't perfect or infallible, but it's how we form the best beliefs we can.