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HISTORICAL VIEW OF THE

attending the first endeavours to enquire into thd lawsof the material world. The Aristotelian philosophytended to increase the difficulty, by representing allthings as full of irregularity and confusion, and theprinciples of heat and cold, moisture and dryness, asin a state of perpetual warfare; thus the motion ofbodies on the earth’s surface was considered to be of anature essentially different from that of the heavenlybodies; all attempts, therefore, to refer them to commonlaws were supposed useless. Perhaps, indeed, it maybe a fair question, whether this part of the system isnot really consistent with the true principles of inductivephilosophy; for certainly we are not warranted in in-ferring the existence of order and connection, until wehave at least traced some indications of it; nor couldthe celestial and terrestrial motions be entitled to beclassed together, until we had some experimental groundsfor doing so: they were properly set down as each athing “ sui generis,” until they could be shown to bereferable to one common “ genus.”

The ancients, then, were wanting in the power oftracing the relations between one class of facts andanother, and this could only be attained by the ex-tended use of observation, on the one hand, in all caseswhich presented themselves beyond the reach of ourpowers to control; and on the other, by carefullymaking repetitions and new combinations, in a word,experiments , on all cases within our command.

Now, in many departments of observation, we haveseen, they were not only not deficient, but eminentlydiligent and successful; those classes of facts, therefore,they were able to trace with accuracy, but they failedin perceiving their relations to others. This was doubt-less occasioned, in part at least, by the imperfection ofmuch of their process of observation, and the almosttotal absence of experiment. The contrast is ex-tremely remarkable between their astronomy and theirdynamics ; between the elaborate care with which theydetermined the motions of the celestial bodies, and their