If we work upon marble, it will perish; if we work upon brass, time will efface it; if we rear temples, they will crumble into dust; but if we work upon immortal minds and instill into them just principles, we are then engraving that upon tablets which no time will efface, but will brighten and brighten to all eternity.

Webster contrasts material monuments—marble statues, brass inscriptions, and even grand temples—with the more durable legacy of shaping human character. The passage argues that physical works inevitably decay, while moral and intellectual formation can outlast generations because it is carried forward in living persons and institutions. The imagery of “engraving” on “immortal minds” recasts education and ethical instruction as a kind of higher craftsmanship: the teacher, statesman, or reformer creates a legacy not by building objects but by cultivating principles that persist and even intensify over time. It is also a civic claim: a republic’s true permanence depends less on buildings than on the virtues of its citizens.