6. In the same manner we form a conception of infinite time, by supposing time to begin now, and to go on, after the nature of time, without limit; or by going back in thought from the present to a past time, and by continuing this retrogression without limit. And thus we have time infinite _a parte ante_ and _a parte post_, as the phrase used to run; and time infinite both ways includes both, and is the most complete notion of eternity. 7. Perhaps those who thus maintain that we cannot conceive anything infinite, mean that we cannot form to ourselves a definite image of anything infinite. And this of course is true. We cannot form to ourselves an image of anything of which one of the characteristics is that it is, in a certain way, unlimited. But this impossibility does not prevent our reasoning about infinite quantities; combining as elements of our reasoning, the absence of a limit with other positive characters. 8. One of the consequences which is drawn by the assertors of the doctrine that we cannot know anything about Infinity, is that we cannot obtain from science any knowledge concerning God: And I have been the more desirous to show the absence of proof of this doctrine, because I conceive that science _does_ give us some knowledge, though it be very little, of the nature of God: as I shall endeavour to show hereafter. For instance, I conceive that when we say that God is an _eternal_ Being, this phraseology is not empty and unmeaning. It has been used by the wisest and most thoughtful men in all ages, and, as I conceive, may be used with undiminished, or with increased propriety, after all the light which science and philosophy have thrown upon such declarations. The reader of Newton will recollect how emphatically he uses this expression along with others of a cognate character[302]: "God is eternal and infinite, ... that is, He endures from eternity to eternity, and is present from infinity to infinity.... He is not eternity and infinity, but eternal and infinite. He is not duration and space, but He endures and is present. He endures always, and is present everywhere, and by existing always and everywhere He constitutes duration and space." We shall see shortly that the view to which we are led may be very fitly expressed by this language. But I will first notice some other aspects of this philosophy. FOOTNOTES: [Footnote 298: _Hist. Ind. Sc._ b. ix. c. iii.] [Footnote 299: _Ibid._ b. vii. c. ii.] [Footnote 300: Sir W. Hamilton's Note on the _Philosophy of the Unconditioned_.] [Footnote 301: Werenfels in Mr. Mansel's _Bampton Lectures_, lect. ii. Note 15.] [Footnote 302: _Scholium Generale_ at the end of the _Principia_.] CHAPTER XXVII. SIR WILLIAM HAMILTON ON INERTIA AND WEIGHT.