Meaning of “Its one source is the knowledge of Ideas;…”

The Sense of Beauty (1896), Part I, §11, ‘The definition of beauty,’ Project Gutenberg #26842; the represented section begins on printed page 49. ‘Beauty is pleasure regarded as the quality of a thing’ is Santayana’s summary definition after describing beauty as positive, intrinsic and objectified value. This remains historical naturalistic aesthetic theory / philosophical psychology, not a modern empirical test proving an object objectively beautiful.

The World as Will and Idea, Vol. I, First Book, §1, Haldane and Kemp translation, Project Gutenberg #38427. “Idea” translates Vorstellung in this historical philosophical vocabulary and should not be read as the everyday sense of a passing thought.

“Ode on a Grecian Urn,” in Keats: Poems Published in 1820; Project Gutenberg #23684. The words are presented as the urn’s closing message, so the source page preserves the dramatic-poetic framing.

Endymion: A Poetic Romance (1818), Book I, line 1, Project Gutenberg #24280, reproducing the Taylor and Hessey 1818 text. “A thing of beauty is a joy for ever” opens the poem’s mythic Romantic meditation on beauty; the statement remains a poetic proposition rather than empirical evidence that every aesthetic experience produces permanent happiness.

The Marriage of Heaven and Hell, “Proverbs of Hell,” represented by Project Gutenberg #45315 at printed page 16. Gutenberg regularizes the line to “imagined”; Blake’s engraved text is often transcribed with historical spelling and punctuation. The proverb is part of Blake’s deliberately paradoxical infernal-wisdom sequence, not a literal claim that every imagined thing will eventually be proved.

Essays in the Art of Writing, “On Some Technical Elements of Style in Literature,” represented by the 1905 Chatto & Windus edition in Project Gutenberg #492. The collection is posthumous; the excerpt concerns literary aesthetics.