Cyclopum educta caminis

Mænia conspicio, atque adverso fornice portas.

His demum exactis, perfecto munere Divæ,
Devenere locos lætos et amæna vireta
Fortunatorum nemorum sedesque beatas.
Largior hic campos æther et lumine vestit
Purpureo solemque suum, sua sidera norunt.

VIRGIL, En. vi. 630.

They leave at length the nether gloom, and stand
Before the portals of a better land :

To happier plains they come, and fairer groves,
The seats of those whom heaven, benignant, loves
A brighter day, a bluer ether, spreads

Its lucid depths above their favoured heads;
And, purged from mists that veil our earthly skies,
Shine suns and stars unseen by mortal eyes.

;

INTRODUCTION.

Of Formal and Physical Astronomy.

We have thus rapidly traced the causes of the almost complete blank which the history of physical science offers, from the decline of the Roman empire, for a thousand years. Along with the breaking up of the ancient forms of society, were broken up the ancient energy of thinking, the clearness of idea, and steadiness of intellectual action. This mental declension produced a servile admiration for the genius of the better times, and thus, the spirit of commentation; Christianity established the claim of truth to govern the world; and this principle, misinterpreted and combined with the ignorance and servility of the times, gave rise to the dogmatic system: and the love of speculation, finding no secure and permitted path on solid ground, went off into the regions of mysticism.

The causes which produced the inertness and blindness of the stationary period of human knowledge, began at last to yield to the influence of the principles which tended to progression. The indistinctness of thought, which was the original feature in the decline of sound knowledge, was in a measure remedied by the steady cultivation of pure mathematics and astronomy, and by the progress of inven

tions in the arts, which call out and fix the distinctness of our conceptions of the relations of natural phenomena. As men's minds became clear, they became less servile: the perception of the nature of truth drew men away from controversies about mere opinion; when they saw distinctly the relations of things, they ceased to give their whole attention to what had been said concerning them; and thus, as science rose into view, the spirit of commentation lost its sway. And when men came to feel what it was to think for themselves on subjects of science, they soon rebelled against the right of others to impose opinions upon them. When they threw off their blind admiration for the ancients, they were disposed to cast away also their passive obedience to the ancient system of doctrines. When they were no longer inspired by the spirit of commentation, they were no longer submissive to the dogmatism of the schools. When they began to feel that they could discover truths, they felt also a persuasion of a right and a growing will so to do.

Thus the revived clearness of ideas, which made its appearance at the revival of letters, brought on a struggle with the authority, intellectual and civil, of the established schools of philosophy. This clearness of idea showed itself, in the first instance, in astronomy, and was embodied in the system of Copernicus; but the contest did not come to a crisis till a century later, in the time of Galileo and other disciples of the new doctrine. It is our present business to trace