In my dissertation, I argue that self-opacity is an essential feature of human agency that can contribute to moral development. This often-disorienting experience is familiar from ordinary life and is a frequent theme of literature and film, yet it has not received adequate philosophical attention. My work challenges dominant approaches to moral philosophy that privilege self-transparency and reflection as essential to human agency (especially thinkers following rationalist or deliberative endorsement conceptions of agency). Such theories tend to conceive of self-opacity merely negatively, as a contingent failure of agency and thereby as an ethical failure. Against this, I argue, first, that self-opacity is essential to human agency, thanks to two mutually informing dimensions of human life: our animality and our sociality. Second, I argue that self-opacity can contribute productively to ethical life, such that it is possible not just to tolerate self-opacity, but to live well with it. I show that cultivating a non-defensive relationship with self-opacity is crucial to moral growth.