Chap. i. PHILOSOPHICAL DISCOVERIES. 7

niils, may invent systems that will perhaps be greatly admiredfor a time ; these however are, phantoms which the force oftruth will sooner or later difpell: and while we are pleas’d withthe deceit, true philosophy, with all the arts and improvementsthat depend upon it, suffers. The real state of things escapesour observation : or, if it presents itself to us, we are apt eitherto reject it wholly as fiction, or, by new efforts of a vain in-genuity, to interweave it with our own conceits, and labourto make it tally with our favourite schemes. Thus, by. blending together parts so ill suited, the whole comes forth anabsurd composition os truth and error.

Of the many difficulties that have stood in the way ofphilosophy, this vanity perhaps has had the worst effects.The love of the marvellous, and the prejudices of sense, ob-structed the progress of natural knowledge; but experienceand reflection soon taught men to examine and endeavour tocorrect these. Tho' philosophers met with great discourage-ments in the dark and superstitious ages, learning flourished,with liberty, in better times. The disputes amongst the sects,more fond of victory than of truth, produced a talkative sortof philosophy, and a vain ostentation of learning, that pre-vailed for a long time ; but men could not be always di-verted from pursuing after more real knowledge. These havenot done near so much harm, as that pride and ambition,which has led philosophers to think it beneath them, to offerany thing less to the world than a compleat and finishedsystem of nature ; and, in order to obtain this at once, totake die liberty of inventing certain principles and hypotheses,from which they pretend to explain all her mysteries.

2. Sir Isaac Newton saw how extravagant such attempts*were, and therefore did not set out with any favourite prin-ciple

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