Following Locke's footsteps, the French had discovered that 'as the stomach secretes chyle, so does the brain secrete thought.'"[167] The sentiments of Bonnet of Geneva, as stated in his "Palingenesie," are substantially in accordance with those of Locke, and have met with similar treatment.

He is not a Materialist; he admits a real distinction, as well as a close union, between the soul and the body; he speaks even of the possible existence of disembodied souls or pure spirits; he affirms the immateriality of the thinking principle; and expressly assigns his reasons for _not_ being a Materialist.[168] But he appears to have thought, as Locke did, that possibly the power of thinking might be superadded to matter, by the Creator's omnipotent will, and that there is nothing in this supposition which could seriously affect either the doctrine of Theism or the "immortality" of man.

And hence he affirmed, in words which Dr.Priestley selected for the motto of his "Disquisitions," that "if any one should ever demonstrate the soul to be material, far from being alarmed at this, we should only admire the power which could give to _matter_ the power of _thinking_." We conceive that the language both of Locke and Bonnet on this particular point amounts to a dangerous and very unnecessary concession.
Were it meant merely to affirm that God could so unite a thinking spiritual being with a material organism, as to make the two mutually dependent and subservient, this is no more than is admitted by all the advocates of Immaterialism, and it is actually exhibited in the constitution of human nature.

But if it were meant to admit that the power of "thinking" and "willing" might be superadded as a property or quality to matter itself, _without any substantive being other than matter as a substratum_, then we conceive it to be at variance with the grounds on which Locke and Bonnet themselves had previously declared their belief in the distinct existence both of matter and spirit.

We shall only add, that the prejudice against our doctrine, which is founded on the union of two _substances_ apparently so heterogeneous as mind and matter in _the same person_, is, to say the least, fully counterbalanced by the difficulty, incident to the theory, of demonstrating the coexistence of _two sets of properties_, apparently so diverse and disparate as thought and extension, "vis inertiae" and spontaneity, in _the same substance_.
On the whole, we conclude that the same reason which warrants us in ascribing certain properties or phenomena to a distinct substance called "matter," equally warrants us in ascribing certain other properties or phenomena to a distinct substance called "mind;" and that the difference between their properties and phenomena is so great as to justify the belief that the substances are different, and ought to be denominated by distinctive names.
V.Our _fifth_ proposition is, That it is impossible to account for the phenomena of thought, feeling, desire, volition, and self-consciousness, by ascribing them, as Materialists do, either to the _substance of_ "matter," or to its _form_; that is, either to the _atomic particles_ of which it consists, or to the _peculiar organization_ in which these particles are arranged.
It is too manifest to admit either of doubt or denial, that the power of thinking, feeling, and willing, does not belong to every form of matter.
It is not, therefore, one of its essential properties; and if it belong to it at all, it must be either a _quality superadded_ to the ordinary powers of matter, or a _product resulting_ from its configuration in an organized form.
If it be a quality superadded merely to the ordinary powers of matter, then it must exist equally in every part of the mass to which it is attached; every particle of the matter in which it inheres must be sentient, intelligent, voluntary, and active; and, on this supposition, it will remain a difficult, if not desperate problem, to account for the _unity_ of consciousness by such a diversity of parts, and especially for the _continuity_ of consciousness, when the material elements are confessedly in a state of constant flux and mutation.