I am too sensible of the pains you have taken in the art of chemistry, to discover the principles of natural bodies, and wish they had been more profitably bestowed upon some other, than such experiments; for both by my own contemplation, and the observations which I have made by my rational and sensitive perception upon nature, and her works, I find, that nature is but one infinite self-moving body, which by the virtue of its self-motion, is divided into infinite parts, which parts being restless, undergo perpetual changes and transmutations by their infinite compositions and divisions. Now, if this be so, as surely, according to regular sense and reason, it appears no otherwise; it is in vain to look for primary ingredients, or constitutive principles of natural bodies, since there is no more but one universal principle of nature, to wit, self-moving matter, which is the only cause of all natural effects.