ruYSICAL AND MATHEMATICAL SCIENCES. 87

this distinction. The mind of that great philosopherwas cast in so purely abstractive a mould, that he couldproceed upon no other model to fashion his system ofnature. It was not, as is often incorrectly alleged,that he neglected to collect facts, for he was mostindustrious in doing so; but he did not consider thecollection of facts to have any reference to that scientificclassification of ideas, which he made the groundworkof all his theories. Hence he presents us with a massof statements of facts, more or less correctly determined,and of natural phenomena observed with more or lessaccuracy ; but these have no correspondence with theabstract principles which he lays down as the ground-work of his reasoning.

For illustration take his definitions (if such they canbe ealled)--of motion,, and of light. “ Motion is theact of a being in power, so far as it is in- power,” and“ light is the act or energy of a transparent body, in-asmuch as it is transparent.” That is, he first as-sumed the notion of body or being, then that of act orenergy; things were to be considered either as in actor energy, or in capacity or power: motion then wouldbe the peculiar characteristic of body considered as inenergy; light again, (which, as we observed before, heregarded as not material, but as the result of some kindof impulse,) was that sort of energy which is character-istic of transparency. By this sort of systematisingfrom metaphysical distinctions and the primary adoptionof some vague generalities, such as the repugnance ofnature to all motions but those which are natural, theabstract perfection of circular motion, &c., was the wholetheory of the peripatetic system constructed; ancf toattempt to square nature to these imaginary principleswas alone considered to be true philosophy.

The seeming irregularity and confusion which atfirst sight appears to pervade the multifarious pheno-mena of nature, and to render hopeless all attempts toanalyse them into any sort of order, must, doubtless,have been one of the most discouraging circumstancesg 4