The atomists,
who define motion to be "a passage from one place to another," what do
they more than put one synonymous word for another? For what is
passage other than motion? And if they were asked what passage was,
how would they better define it than by motion? For is it not at least
as proper and significant to say, Passage is a motion from one place
to another, as to say, Motion is a passage, &c.? This is to translate,
and not to define, when we change two words of the same
signification one for another; which, when one is better understood
than the other, may serve to discover what idea the unknown stands
for; but is very far from a definition, unless we will say every
English word in the dictionary is the definition of the Latin word
it answers, and that motion is a definition of motus. Nor will the
"successive application of the parts of the superficies of one body to
those of another," which the Cartesians give us, prove a much better
definition of motion, when well examined.
10. Definitions of light. "The act of perspicuous, as far forth as
perspicuous," is another Peripatetic definition of a simple idea;
which, though not more absurd than the former of motion, yet betrays
its uselessness and insignificancy more plainly; because experience
will easily convince any one that it cannot make the meaning of the
word light (which it pretends to define) at all understood by a
blind man, but the definition of motion appears not at first sight
so useless, because it escapes this way of trial.
Pages:
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623