Unum · verum · bonum
Unity, truth and goodness accompany being and reveal its intelligible depth
The transcendentals are not additional properties attached to some beings. They name being under aspects that extend beyond every genus. Every being is one insofar as it is undivided in itself; true insofar as it is intelligible and proportioned to intellect; good insofar as it is perfective and desirable. These notions are really grounded in being while differing conceptually according to relation and emphasis.
Unity explains why a substance is more than a heap. Truth explains why reality can measure judgment. Goodness explains why every appetite tends toward an apprehended perfection. Evil is consequently not a positive nature equal and opposite to good. It is a privation of due good in a subject: blindness in an eye, injustice in a will, disorder in an action. This account will later be indispensable for the problem of evil.
Beauty is often associated with the transcendentals because it joins intelligibility and delight: integrity, proportion and clarity make form present to a knowing subject in a way that pleases upon apprehension. One should not reduce beauty to private taste, yet concrete aesthetic judgment can involve cultural formation, bodily conditions and individual sensitivity. Its metaphysical root lies in the splendour of form and the fittingness of order.
The fourth way ascends through participated transcendental perfection; the fifth through ordered operation. Together they show that natural theology is not limited to asking why matter began. It asks why being is unified, intelligible, good and directed. The first cause must account for these features without receiving them in a limited mode from another.
Reader path: Summa Theologiae I, q. 5-6, 11, 16 · Augustine, De natura boni
