The Greeks and Romans, whose principles of art the moderns have chiefly imitated, personified certain ideas of their social state, deified and worshiped them. As a general rule, they found in nature the types which they idealized; in some cases, from ignorance, superstition, or love of the marvelous, they departed from nature, and to that extent, in my judgment, their art was false. Art, as I understand it, should be the interpreter of nature, without too servile an imitation; art may transfigure nature, but should never be false to it; unnatural and, I may add (as far as knowledge is concerned), supernatural art is monstrosity.
By monstrosity (which is here used in its scientific, not its popular sense) I mean nothing ugly, misshapen, gigantic, or dwarfish, or with any congenital anomalies of conformation, rendering impossible the accomplishment of the ordinary functions of life, but the union of parts incompatible with each other, and impossible when brought to the test of reason and natural laws, however beautiful or suggestive they may be, and however consecrated by unquestioning ages of social, religious, and æsthetic acceptance. It is true, as Goethe has well said, that "it is in her monstrosities that Nature reveals to us her secrets," which we now know are but the expressions of natural laws; I hope to show that in the monsters of art she only reveals to us her weakness.
To illustrate my meaning by a few examples: The ancients, when they represented Saturn as Chronos or Time, the father of the gods, as an old man devouring his children (hours and days and years), armed with a scythe by which he cut down the generations of man, conceived a beautiful, expressive, and natural idea; but when they put upon him a pair of wings, to indicate the velocity of his flight, he became a monster, for the reason that arms and wings and legs are incompatible, and can not exist in nature, as we know the vertebrate skeleton. Six pairs of limbs are conceivable with the vertebrate skeleton, but wings without bones to support or muscles to move them are not conceivable.
Among other winged and impossible monsters created by ancient art, expressing long-cherished ideas, is Cupid or Love—though if would be an anatomical impossibility to move said wings; he must drop either his arms, with the bow and arrows, or his wings. So Mors or Death, represented by a skeleton, has enormous wings, with not a muscle to move either bone or pinion; Morpheus the minister of Somnus or Sleep, Psyche the Soul, and Zephyr the West Wind, have the wings of a butterfly—a mixture of vertebrate and invertebrate characters entirely incompatible.
The wonderful adaptation of the human skeleton to its uses—the contour of the spine, which renders erect position and biped locomotion possible in him alone of mammals; the lower limbs for locomotion only; the upper limbs for prehension, and the service of the senses resident in the head—all these imply a certain bony structure and corresponding muscular developments. If you add another pair of limbs as wings,
