Form in philosophy spans metaphysics (Plato's Forms, Aristotle's formal cause), aesthetics (the relationship between form and content), and philosophy of language (logical form). Plato's theory of Forms (eide) holds that the observable world is an imperfect copy of eternal, unchanging archetypes — the Form of Beauty, the Form of Justice — which are the proper objects of philosophical knowledge. Aristotle reformulates Form as the formal cause of a thing — the principle of organization that makes it the kind of thing it is, internal to the thing rather than transcendent. In Kantian aesthetics, form (specifically the form of purposiveness without purpose) is what is appreciated in genuine aesthetic judgment. In the New
Criticism, form and content are treated as inseparable — the poem's meaning cannot be paraphrased away from its formal realization. For poets, the
choice of form is
never merely technical but always also philosophical. Related terms: Plato's eide, Aristotle's four causes, formal cause, Kant's purposiveness, organic form, New Critical unity.