25. I allow it is usual for most people to wonder how any one should find a difficulty in what they think they every day observe. Do we not see (will they be ready to say) the parts of bodies stick firmly together? Is there anything more common? And what doubt can there be made of it? And the like, I say, concerning thinking and voluntary motion. Do we not every moment experiment it in ourselves, and therefore can it be doubted? The matter of fact is clear, I confess; but when we would a little nearer look into it, both in the one and the other; and can as little understand how the parts of body cohere, as how we ourselves perceive or move. I would have any one intelligibly explain to me how the parts of gold, or brass, (that but now in fusion were as loose from one another as the particles of water, or the sands of an hour-glass,) come in a few moments to be so united, and adhere so strongly one to another, that the utmost force of men’s arms cannot separate them? A considering man will, I suppose, be here at a loss to satisfy his own, or another man’s understanding. 26. The cause of coherence of atoms in extended substances incomprehensible. The little bodies that compose that fluid we call water are so extremely small, that I have never heard of any one who, by a microscope, (and yet I have heard of some that have magnified to ten thousand; nay, to much above a hundred thousand times,) pretended to perceive their distinct bulk, figure, or motion; and the particles of water are also so perfectly loose one from another, that the least force sensibly separates them. Nay, if we consider their perpetual motion, we must allow them to have no cohesion one with another; and yet let but a sharp cold come, and they unite, they consolidate; these little atoms cohere, and are not, without great force, separable. He that could find the bonds that tie these heaps of loose little bodies together so firmly; he that could make known the cement that makes them stick so fast one to another, would discover a great and yet unknown secret: and yet when that was done, would he be far enough from making the extension of body (which is the cohesion of its solid parts) intelligible, till he could show wherein consisted the union, or consolidation of the parts of those bonds or of that cement, or of the least particle of matter that exists. Whereby it appears that this primary and supposed obvious quality of body will be found, when examined, to be as incomprehensible as anything belonging to our minds, and a solid extended substance as hard to be conceived as a thinking immaterial one, whatever difficulties some would raise against it. 27. The supposed pressure [*dropped word] explain cohesion is unintelligible.