From Animal Faith and Spiritual Life
First in the order of genesis comes essence since it spreads out the field of forms through which existence may travel and may pick up one form after another along its special path. Matter in this order is second and truth third; for truth is the ideally complete description of the existing world, as it is, has been, and is to be. Finally spirit with all its discoveries comes last, because the psyche—without which spirit could not arise or live—is a trope established in matter; that is to say, a truth concerning the order and cohesion of certain events in the flux of nature. The tropes proper to spirit—the passions expressed in morals and in literary psychology—are truths about spirit which of course presuppose its existence: but the discovery of these tropes is itself subsequent to them; so that even here, when spirit considers its own career, the relevant spiritual act, the moral sentiment or psychological insight, chronicles a prior truth, and brings into the light of consciousness an order in events which, though the events were spiritual, had hitherto uncoiled itself unnoticed in the natural world.
Animal Faith '67 at 145-46 ("The Order of Genesis and the Order of Discovery").
From Letters of George Santayana
I am writing a brand new system of philosophy to be called 'Three Realms of Being'—not the mineral vegetable and animal, but something far more metaphysical, namely Essence, Matter and Consciousness.
Letters '55 at 104 ("To Susana Sturgis de Sastre, May 16, 1911").
From Scepticism and Animal Faith
The truth, however nobly it may loom before the scientific intellect, is ontologically something secondary.
From Realms of Being
[Man] seldom has leisure to dwell on essences apart from their presumable truth; even their beauty and dialectical pattern seem to him rather trivial, unless they are significant of facts in the realm of matter, controlling his destiny. I therefore give a special name to this tragic segment of the realm of essence and call it the Realm of Truth.
From Realms of Being
We have seen that the truth, as I take the word, is subservient to existence: it is ontologically secondary and true of something else.
Realms '72 at 445 ("The Realm of Truth: Radiation of Truth").
From Realms of Being
Within the fanatical defence of vested illusions there may be a sacrificial respect for things beyond us, whatever those secret realities may be; and the martyr that on earth is ready to die for some false opinion may be judged in heaven to have died for the truth. The very absurdity of a tenet, or its groundlessness, at least proves that imagination is at work, and groping for an issue from animal darkness. At least the category of truth has been set up. Appearances, innocent and perfectly real in themselves, have begun to be questioned and discounted as deceptive; and this not merely against the blank background of a posited substance, known only as a force, but in contrast to a possible and more adequate description of that substance and of the manner in which it produces appearances. Intelligence has begun the pursuit of truth.
Realms '72 at 515-16 ("The Realm of Truth: Love and Hatred of Truth").
From Realms of Being
Matter in any one of its moments and in any one of its atoms offers no foothold for consciousness: but let certain tropes and cycles be established in the movement of matter, let certain kinds of matter cohere and pulse together in an organism, and behold, consciousness has arisen. Now tropes, cycles, organisms, and pulsations, with all the laws of nature, are units proper to the realm of truth; units that bridge the flux of existence and are suspended over it, as truth and spirit also are suspended.
Realms '72 at 516-17 ("The Realm of Truth: Love and Hatred of Truth").
From Philosophy of George Santayana
Materialism by no means implies that nothing exists save matter. Democritus admitted the void to an equal reality, with all the relations and events that motion in the void would involve: he thereby admitted what I call the realm of truth.
From Philosophy of George Santayana
Under the form of truth change and motion become visible; in precipitation, in self-abolishing flux from instant to instant, they are perfectly invisible and unconscious of themselves.
From Realms of Being
This simple dissolution of superstition yields three of my realms of being: matter . . . ; essence . . . ; and spirit . . . . There remains the realm of truth . . . .
From Realms of Being
[M]y analysis transposes the doctrine of the Trinity into terms of pure ontology and moral dialectic.
[P]ower [the realm of matter] is signified by the First Person of the Trinity, the Father . . . .
Yet . . . power could not possibly produce anything unless it borrowed some form from the realm of essence . . . .
[B]y the intervention of irrational power . . . the infinity of essence is determined to a particular complex or series of forms . . . . This complex or series of forms exemplified in the universe composes the truth about it . . . . It is the Logos . . . .
[The] third dimension of reality is spirit. Christian theology has been much less curious and penetrating in regard to the Holy Ghost than in regard to the Father and the Son . . . .
Realms '72 at 845-48 ("General Review of Realms of Being") (emphasis added at 848).
From Idea of Christ in the Gospels
[T]hat in which [Philo's] Logos became flesh was not a particular man, but the whole creation and the whole history of the world. I don't know in what circumstances this incarnation or phenomonalising of the Platonic ideas came to be assimilated to the son of God, become man. The fact that in Christ the power and the wisdom of God were manifested, established the analogy: but an anomaly seems to appear when we consider how remote from the Logos or the Nous was the inspiration of Christ. His mission was not to create but to redeem and to save; and his wisdom spoke in parables and precepts, not in grammatical or conceptual hierarchies of terms. He was a living person, not the morphology of the universe. I cannot help thinking that it was an unfortunate accident that the Son of God and the wisdom of God should have seemed to coincide, as being both immediately and inwardly generated within the divine life, and thought of as its second term. That divine element which seems to descend into the created soul is rather life than wisdom, rather the Psyche, than the Logos: but something of the Logos may descend too, and we find in John a number of other terms, the Light, the Way, the Truth, that fall in well with the mediating office of Christ, as teacher and redeemer. Yet there are still other terms, Life and Love, that seem to fit better the intimate essence of his person, as if he were spirit incarnate, rather than the Word.
From Physical Order and Moral Liberty
But nature is more than substance; it is a system of movements, forms, and transformations, which have their specific being in the realm of truth. This realm is non-natural in one respect; it is eternal.
Physical Order '69 at 157 ("The Relations of Spirit to Time").