Ye sacred Muses, with whose beauty fir'd, My soul is ravisht and my brain inspir'd: Whose Priest I am, whose holy fillets wear, Would you your Poet's first petition hear, Give me the ways of wand'ring stars to know, The depth of Heaven above and Earth below; Teach me the various labours of the Moon, And whence proceed th' eclipses of the Sun; Why flowing Tides prevail upon the main, And in what dark abyss they shrink again; What shakes the solid Earth; what cause delays The Summer Nights; and shortens Winter Days.... Happy the man who, studying Nature's Laws, Through known effects can trace the secret cause! Ovid[40] expresses a similar feeling. Felices animos quibus hæc cognoscere primis Inque domos superas scandere cura fuit!... Admovere oculis distantia sidera nostris Ætheraque ingenio supposuere suo. Sic petitur cœlum: non ut ferat Ossam Olympus Summaque Peliacus sidera tanget apex. Thrice happy souls! to whom 'twas given to rise To truths like these, and scale the spangled skies! Far distant stars to clearest view they brought, And girdled ether with their chain of thought. So heaven is reached:--not as of old they tried By mountains piled on mountains in their pride. And from the whole tenour of these and similar passages, it is evident that the intellectual pleasure which arises from our first introduction to a beautiful physical theory had a main share in producing this enthusiasm at the contemplation of the victories of science; although undoubtedly the moral philosophy, which was never separated from the natural philosophy, and the triumph over superstitious fears, which a knowledge of nature was supposed to furnish, added warmth to the feeling of exultation. We may trace a similar impression in the ardent expressions which Pliny[41] makes use of in speaking of the early astronomers, and which we have quoted in the _History_. "Great men! elevated above the common standard of human nature, by discovering the laws which celestial occurrences obey, and by freeing the wretched mind of man from the fears which eclipses inspired." This exulting contemplation of what science had done, naturally led the mind to an anticipation of further achievements still to be performed. Expressions of this feeling occur in Seneca, and are of the most remarkable kind, as the following example will show[42]: "Why do we wonder that comets, so rare a phenomenon, have not yet had their laws assigned?--that we should know so little of their beginning and their end, when their recurrence is at wide intervals? It is not yet fifteen hundred years since Greece, Stellis numeros et nomina fecit,