There can be no voice where there is no motion or percussion of the
air; there can be no percussion of the air where there is no
instrument, there can be no instrument without a body; and this
being so, a spirit can have neither voice, nor form, nor strength.
And if it were to assume a body it could not penetrate nor enter
where the passages are closed. And if any one should say that by
air, compressed and compacted together, a spirit may take bodies of
various forms and by this means speak and move with strength--to him
I reply that when there are neither nerves nor bones there can be no
force exercised in any kind of movement made by such imaginary
spirits.

Beware of the teaching of these speculators, because their reasoning
is not confirmed by experience.