The classical instance of the development of this idea is found in the cult of the Greek Hestia, the Latin Vesta, a goddess who was the personification of fire, the guardian of the household altar and of the welfare of cities and nations. She was worshipped fairly widely in Greece and Asia Minor, but principally in Rome, where a beautiful circular temple was dedicated to her service; her ministers, the Vestal virgins, were held in the greatest honour and were chosen from among the loveliest and noblest of Roman maidens. In this temple was kept ever brightly burning the sacred fire supposed to have been kindled by the rays of the sun, and to have been brought by AEneas when he founded his kingdom in the new land of Italy. The extinction of this fire would have been regarded as the gravest public calamity, foreboding disaster. Its flames were intended to represent the purity of the goddess, thus emphasising the mystic aspect of another physical property of fire—its purifying power. "Our God" (said the writer of the Epistle to the Hebrews) "is a consuming fire."

Greece had its common hearth at Delphi. It was also supposed that at the centre of the earth there was a hearth which answered to that. In the Apocalypse we read of the altar with its sacred fire as central in heaven. Truly these concepts are persistent! And why? Because there is more than imagination in them; they are the products of ideas immanent in the material phenomena in which they are embodied, and through which they manifest themselves to the human soul.

There could not fail to be fire-gods many, and a study of their respective characters, especially in the earlier stages of their development, often furnishes a key to the intuitional workings of the primitive mind as prompted by the always arresting, and often terrorising phenomena of fire and flame. Max Müller's detailed study of the development of the Hindu god, Agni, was mentioned in an earlier chapter. The name originally means the Mover, and arose, doubtless, from the running, darting, leaping movement of flame. Beginning his career as a purely physical god, he advanced through various stages of spiritualisation until he became the supreme deity. Is not the problem of motion still one of the most fascinating and profound? Bergson's "L'Evolution créatrice" is one of the latest attempts to grapple with it, and those who in early India personified fire as the Mover were his legitimate predecessors.

The Greek Hephaestus personified the brightness of flame, and took shape as a god of ripe age, of muscular form, of serious countenance, but lame. Why lame? Why this physical defect as a drawback to so much physical beauty and strength? A Frenchman, Emérie, suggests—"attendu la marche inégale et vacillante de la flamme." Certainly fire, as compared with water and air, is dependent on sustenance, as Heracleitus so well realised, as also its consequent limitations in regard to free and independent movement: but the sage solved this difficulty by making the Fire-motion feed, as it were, upon itself. The god was represented as puny at birth because flame, especially as kindled artificially, so often starts from a tiny spark. His marriage to Aphrodite typifies "the association of fire with the life-giving forces of nature." So, remarks Max Müller, the Hindu Agni was the patron of marriage. How many lines of thought open out before us here, bringing us face to face, by pre-scientific modes of mental activity, with some of the deepest mysteries of human life!

Vulcan, the Latin parallel of Hephaestus, suggests to us the awe-inspiring phenomena of volcanoes, which, though not of frequent occurrence, are calculated by virtue of their magnitude and grandeur to stimulate emotion and intuition to an exceptional degree. Fear would naturally predominate, but, even for the primitive mind, would be one factor only in a complex whole. Matthew Arnold has attempted to portray the soul-storm raised by the sight of the molten crater of AEtna. He makes Empedocles, the poet-philosopher, climb the summit of the mountain, gaze for the last time on the realm of nature spread around, and apostrophise the stars above and the volcanic fires beneath his feet.

"And thou, fiery world,
That sapp'st the vitals of this terrible mount
Upon whose charred and quaking crust I stand—
Thou, too, brimmest with life."

Note here again the sense of life—of kinship, so fundamental to Nature Mysticism. And so to the close.

"And therefore, O ye elements! I know—
Ye know it too—it hath been granted me
Not to die wholly, not to be all enslaved.
I feel it in this hour. The numbing cloud
Mounts off my soul; I feel it, I breathe free,
Is it but for a moment?
—Ah, boil up, ye vapours!
Leap and roar, thou sea of fire!
My soul glows to meet you.
Ere it flag, ere the mists
Of despondency and gloom
Rush over it again,
Receive me, save me!
[He plunges into the crater.]"

Out of the ancient beliefs and myths concerning subterranean fires grew up the enormously important beliefs in Hell and Purgatory, which attained such abnormal proportions in medieval times, and which are by no means yet extinct. The most vivid picture of Hell, founded largely on ancient material, though with a Biblical basis, is found in Milton. In language which recalls the Titanomachy, the poet tells of Satan and his myrmidons hurled from heaven.

"Him the almighty Power
Hurled headlong flaming from th' aetherial sky,
With hideous ruin and combustion, down
To bottomless perdition, there to dwell
In adamantine chains and penal fire."