In combinations of poetical images, no regard is had to their consistency with truth and reason. It is the part of philosophy to discover relations as they exist in nature; but to search out and combine into one glowing and harmonious whole the brightest and grandest images which art or nature supplies--this is the province of poetry. The utmost calmness and most collected thought are necessary to that patient and laborious reasoning by which progress is made in the science of truth. The fury of impassioned feeling, on the other hand, supports the loftier flights of poetry. Hence philosophy and poetry rarely meet in the same individual. Yet the smallness of the number of those who have gained renown both as poets and philosophers, is to be ascribed less to any incompatibility between the habits of mind peculiar to each, than to the fact that the short space of human life will not allow to both the attention necessary for their highest attainments. I speak now of poetical and philosophical genius, not of poetry and philosophy. Between the two last there _is_ an incompatibility, as may easily be shown. Euclid's elements, for example, contain as pure specimens of mere reasoning as can be conceived; but in them simplicity, clearness and precision of terms are all the ornament they need or will admit: nor can poetical language be used by any arrangement without producing obscurity and disgust. And the wild conceptions of unbridled fancy will as little brook the restraint of heartless reason. In short, poetry and philosophy are so distinct and opposed in character, that neither can ever be used to heighten the proper effect of the other. A most extraordinary combination of poetical and philosophical talent in one individual was displayed by Lucretius. I might challenge the whole circle of science or literature to furnish examples of clearer, closer and more irrefutable argument than his work presents. And for purity, sublimity, delicacy, strength and feeling, passages of his poetry might be selected scarcely {298} inferior to any effort of ancient or modern times. Yet his work may well be chosen to furnish proof that even the brightest genius cannot combine austere logic and gorgeous poetry, so as that each shall produce its due effect. For although where the reasoning is not deep the embellishments of fancy may be borne and even relished, yet where the argument requires close and laborious thought, the reader is willing to sacrifice all the ornaments of poetry to the simpler grace of perspicuity. But it is mostly in episodes and illustrations that the fire of his poetic genius burns so brightly; and here we see him throw off the fetters of truth to wander in the haunted fields of fiction. And although his work displays intense thought and burning poetry, we rarely find them united in the same passage.