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Sir ISAAC N E W T O N’s Book I.

time : but as his knowledge of nature is founded on the ob-servation of sensible things, he must begin with these, andmust often return to them, to examine his progress by them.Here is his secure hold; and as he sets out from thence, soif he likewise trace not often his steps backwards with caution,he will be in hazard of losing his way in the labyrinths ofnature.

6. From this short view of nature, and of the situation ofman, considered as a spectator of its phænomena and as anenquirer into its constitution, we may form some judgment of theproject of those, who, in composing their systems, begin at thesummit os the scale, and then, by clear ideas, pretend to de-scend through all its steps with great pomp and facility, so as inone view to explain all things. The processes in experimentalphilosophy are carried on in a different manner : the beginningsare less lofty, but the scheme improves as we arise from par-ticular observations, to more general and more just views.

It must be owned, indeed, that philosophy would be perfect,if our view of nature, from the common objects of sense, tothe limits of the universe upwards, and to the elements ofthings downwards, was complete ; and the powers or causesthat operate in the whole were known. But if we comparethe extent of this scheme with the powers of mankind, weshall be obliged to allow the necestity of taking it in parts,and of proceeding with all the caution and care we are capa-ble of, in enquiring into each part. When we perceive suchwonders, as naturalists have discovered, in the minutest objects,shall we pretend to describe so easily the productions of in-finite power in space, that is at the same time infinitely extended ,and infinitely divisible ? Surely we may rather imagine, that inthe whole, there will be matter for the enquiries and perpetualadmiration of much more perfect beings.

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