I need not tell you, what complaints the more candid and judicious of the Chymists themselves are wont to make of those boasters, that confidently pr… - Robert Boyle

But of such writers the number is yet (and will I fear always be so) small, that I shall not need to make many exceptions, when I treat of the usefulness of writing books of essays, in comparison of that of writing systematically: or, at least... whilst I presume not to judge of other men's abilities, I hope it may be lawful for me to confess freely to you concerning myself, that I am very sensible of my being far from having such a stock of experiments and observations, as I judge requisite to write systematically; and I am apt to impute many of the deficiencies to be met with in the theories and reasonings of such great wits as Aristotle, Campanella, and some other celebrated philosophers, chiefly to this very thing, that they have too hastily, and either upon a few observations, or at least without a competent number of experiments, presumed to establish principles, and deliver axioms.

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

And of universal nature, the notion I would offer, should be something like this. Nature is the aggregate of the bodies, that make up the world, in its present state, considered as a principle, by virtue whereof, they act and suffer, according to the laws of motion, prescribed by the author of things.