Anyone who acquires more than the usual amount of knowledge concerning a subject is bound to leave it as his contribution to the knowledge of the world.

Bailey frames specialized knowledge as carrying an ethical obligation. To learn beyond the “usual amount” is not merely personal enrichment; it creates a debt to the wider community. The scholar, scientist, or practitioner becomes a steward of insight and is “bound” to return it—through teaching, publication, practical application, or public service—so that private expertise becomes shared human capital. The quote also implies a cumulative view of knowledge: progress depends on individuals adding their increments to a common store, rather than hoarding expertise as status or advantage. In this sense, Bailey links intellectual achievement to responsibility and generosity.