The beings of the mind are not of clay;
Essentially immortal, they create
And multiply in us a brighter ray
And more beloved existence.

Byron contrasts physical, perishable “clay” with the mind’s creations—ideas, memories, imaginings, and artistic forms—which seem to outlast the body. Such “beings of the mind” are described as “essentially immortal” because they can be preserved, transmitted, and reanimated in others through language and art. The lines suggest that inner life does not merely mirror existence but actively “creates” and “multiplies” it, intensifying experience into a “brighter” and more cherished reality. The passage reflects a Romantic valuation of imagination as a generative power that confers meaning and a kind of afterlife on human feeling and thought.