I come now, Eleutherius, to acquaint you with some of the reasons that have made me backward to entertain such a notion of nature as I have hitherto discoursed of. And I shall at present comprise them under the following five.

1. The first whereof is, that such a nature as we are speaking of seems to me to be either asserted or assumed without sufficient proof. And this single reason, if it be well made out, may (I think) suffice for my turn. For in matters of philosophy, where we ought not to take up anything upon trust or believe it without proof, it is enough to keep us from believing a thing, that we have no positive argument to induce us to assent to it, though we have no particular arguments against it. And if this rule be to take place in lesser cases, sure it ought to hold in this, where we are to entertain the belief of so catholic an agent that all the others are looked upon but as its instruments, that act in subordination to it; and which, being said to have an immediate agency in many of the phenomena of the world, cannot but be supposed to be demonstrable by divers of them. I have yet met with no physical arguments, either demonstrative or so much as considerably probable, to evince the existence of the nature we examine.