'their souls' tender fire'

A wave of yet more tender joy escaped from his heart and went coursing in warm flood along his arteries. Like the tender fires of stars moments of their life together, that no one knew of or would ever know of, broke upon and illumined his memory. He longed to recall to her those moments, to make her forget the years of their dull existence together and remember only their moments of ecstasy. For the years, he felt, had not quenched his soul or hers. Their children, his writing, her household cares had not quenched all their souls’ tender fire. In one letter that he had written to her then he had said: Why is it that words like these seem to me so dull and cold? Is it because there is no word tender enough to be your name?

—James Joyce, “The Dead,” Dubliners (1914)

This Body of Mine

By what rule or manner can I bind this body of mine?...He is my helper and my enemy, my assistant and my opponent, a protector and a traitor. I am kind to him and he assaults me. If I wear him out he gets weak. If he has rest he becomes unruly. If I upset him he cannot stand it. If I mortify him I endanger myself. If I strike him down I have nothing left by which to acquire virtues. I embrace him. And I turn away from him. What is this mystery in me? What is the principle of this mixed nature of body and soul? How can I be my own friend and my own enemy?

—John Climacus, "On Chastity" in The Ladder of Divine Ascent (600)

'the unfathomed distances in himself'

From the first, the baby stirred in the young father a deep, strong emotion he dared scarcely acknowledge, it was so strong and came out of the dark of him. When he heard the child cry, a terror possessed him, because of the answering echo from the unfathomed distances in himself. Must he know in himself such distances, perilous and imminent?

—D.H. Lawrence, The Rainbow (1915)

'Such omniscience ... would extinguish its soul'

In science greater knowledge is always and indisputably good; it is by no means so throughout all human existence. We know it from art proper, where achievement and great factual knowledge, or taste, or intelligence, are in no way essential companions; if they were, our best artists would also be our most learned academics. We can know it by reducing the matter to the absurd, and imagining that God, or some Protean visitor from outer space, were at one fell swoop to grant us all knowledge. Such omniscience would be worse than the worst natural catastrophe, for our species as a whole; would extinguish its soul, lose it all pleasure and reason for living.

—John Fowles, The Tree (1979)

A Man of Noble Breeding

Now against both these dangers there is one safeguard: not to exercise the soul without the body, nor yet the body without the soul, in order that both may hold their own and prove equally balanced and sound. So the mathematician or one who is intensely occupied with any other intellectual discipline must give his body its due meed by taking part in athletic training; while he who is industrious in molding his body must compensate his soul with her proper exercise in the cultivation of the mind and all higher education; so one may deserve to be called in the true sense a man of noble breeding.

—Plato, Timaeus (360 BC)

Thoroughly Pervaded with His Power

When the soul is drawn into the immediate presence of God and is thoroughly pervaded with His power, it becomes like fire, and in this state of glory takes on the appearance of a new higher spirit, a higher nature. When pure fire penetrates a pure metal with its heat, the metal loses its massiveness and hardness, and at the same time gives forth light and warmth, without forfeiting it own essence. In some such way the substantial fire of the divinity penetrates the soul with a heat it irradiates, owing to which the soul loses, not its own nature, but its natural lowliness and ponderousness and is drawn up to God, to receive light and warmth resembling the divine heat.

—Matthias Scheeben, Nature and Grace (1861)

A Soul that is Ruined in the Bud

And what happened was that the precocious boy experienced an unreal second childhood during this period of illness.  His sensibility, robbed of its real childhood, now fled with sudden yearning back to those already dimming years and wandered spellbound through a forest of memories whose vividness was perhaps of an almost pathological nature.  He relived these memories with no less intensity and passion than he had experienced them in reality before.  His betrayed and violated childhood erupted like a long pent-up spring.

When a tree is polled, it will sprout new shoots nearer its roots.  A soul that is ruined in the bud will frequently return to the springtime of its beginnings and its promise-filled childhood, as though it could discover new hopes there and retie the broken threads of life.  The shoots grow rapidly and eagerly, but it is only a sham life that will never be a genuine tree.

-- Hermann Hesse, Beneath the Wheel (1906)