The theory of the perpetual flux was indeed an apprehension of which the full scope was only to be realised by a later age, in alliance with a larger knowledge of the natural world, a closer observation of the phenomena of mind, than was possible, even for Heraclitus, at that early day. So, the seeds of almost all scientific ideas might seem to have been dimly enfolded in the mind of antiquity; but fecundated, admitted to their full working prerogative, one by one, in after ages, by good favour of the special [19] intellectual conditions belonging to a particular generation, which, on a sudden, finds itself preoccupied by a formula, not so much new, as renovated by new application. It is in this way that the most modern metaphysical, and the most modern empirical philosophies alike have illustrated emphatically, justified, expanded, the divination (so we may make bold to call it under the new light now thrown upon it) of the ancient theorist of Ephesus. The entire modern theory of "development," in all its various phases, proved or unprovable,--what is it but old Heracliteanism awake once more in a new world, and grown to full proportions? Panta chôrei, panta rhei+--It is the burden of Hegel on the one hand, to whom nature, and art, and polity, and philosophy, aye, and religion too, each in its long historic series, are but so many conscious movements in the secular process of the eternal mind; and on the other hand of Darwin and Darwinism, for which "type" itself properly is not but is only always becoming. The bold paradox of Heraclitus is, in effect, repeated on all sides, as the vital persuasion just now of a cautiously reasoned experience, and, in illustration of the very law of change which it asserts, may itself presently be superseded as a commonplace. Think of all that subtly disguised movement, latens processus, Bacon calls it (again as if by a kind of anticipation) which [20] modern research has detected, measured, hopes to reduce to minuter or ally to still larger currents, in what had seemed most substantial to the naked eye, the inattentive mind. To the "observation and experiment" of the physical enquirer of to-day, the eye and the sun it lives by reveal themselves, after all, as Heraclitus had declared (scarcely serious, he seemed to those around him) as literally in constant extinction and renewal; the sun only going out more gradually than the human eye; the system meanwhile, of which it is the centre, in ceaseless movement nowhither. Our terrestrial planet is in constant increase by meteoric dust, moving to it through endless time out of infinite space. The Alps drift down the rivers into the plains, as still loftier mountains found their level there ages ago. The granite kernel of the earth, it is said, is ever changing in its very substance, its molecular constitution, by the passage through it of electric currents. And the Darwinian theory--that "species," the