I find that even Eminent Writers (such as Raymund Lully, Paracelsus, and others) do so abuse the termes they employ, that as they will now and then g… - Robert Boyle

Among Latin writers, the acceptations of the word nature are so many, that I remember, one author reckons up no less than fourteen or fifteen. Hence we see how easy 'tis for the generality of men, without excepting those who write of natural things, to impose upon others and themselves, in the use of a word so apt to be mis-employ'd. ..the very great ambiguity of this term, and the promiscuous use made of it, without sufficiently attending to its different significations, render many of the expressions wherein 'tis employ'd either unintelligible, improper, or false.

That then, that I wish for, as to systems, is this, that men, in the first place, would forbear to establish any theory, till they have consulted with (though not a fully competent number of experiments, such as may afford them all the phænomena to be explicated by that theory, yet) a considerable number of experiments, in proportion to the comprehensiveness of the theory to be erected on them. And, in the next place, I would have such kind of supestructures looked upon only as temporary ones; which though they may be preferred before any others, as being the least imperfect, or, if you please, the best in their kind that we yet have, yet are they not entirely to be acquiesced in, as absolutely perfect, or uncapable of improving alterations.

And first the Doctrine that all their Theory is grounded on, seems to me Inevident and undemonstrated, not to say precarious.