23. Cohesion of solid parts in body as hard to be conceived as thinking in a soul.
If any one says he knows not
what it is thinks in him, he means he knows not what the substance is of that thinking thing: No more, say I,
knows he what the substance is of that solid thing. Further, if he says he knows not how he thinks, I answer,
Neither knows he how he is extended, how the solid parts of body are united, or cohere together to make
extension. For though the pressure of the particles of air may account for the cohesion of several parts of matter
that are grosser than the particles of air, and have pores less than the corpuscles of air, yet the weight or pressure
of the air will not explain, nor can be a cause of the coherence of the particles of air themselves. And if the
pressure of the aether, or any subtiler matter than the air, may unite, and hold fast together, the parts of a particle
of air, as well as other bodies, yet it cannot make bonds for itself, and hold together the parts that make up every
the least corpuscle of that materia subtilis. So that that hypothesis, how ingeniously soever explained, by showing
that the parts of sensible bodies are held together by the pressure of other external insensible bodies, reaches not
the parts of the aether itself; and by how much the more evident it proves, that the parts of other bodies are held
together by the external pressure of the aether, and can have no other conceivable cause of their cohesion and
union, by so much the more it leaves us in the dark concerning the cohesion of the parts of the corpuscles of the
aether itself: which we can neither conceive without parts, they being bodies, and divisible, nor yet how their parts
cohere, they wanting that cause of cohesion which is given of the cohesion of the parts of all other bodies.
