218 Transactions.— Miscellaneous. 
founded. It is made upon the collation of the mental phenomena revealed 
to us by self-consciousness, with those physical changes in the grey nervous 
matter of the brain, which are, with great probability, assumed to accom- 
pany the mental phenomena. Let it be supposed that the observer volun- 
tarily enters upon some train of thought—say, the asses’ bridge in Euclid : 
it is assumed, and, I concede, with great probability assumed, that this 
mental process will be exactly represented by concomitant observable 
physical changes in the nervous substance. One may imagine observations 
of this kind brought to a high pitch of accuracy, so that any witness of the 
cerebral phenomena, in the case supposed, should be enabled to infer there- 
from, with certainty, that the subject was in the act of demonstrating Pro- 
position No. 5 of the First Book. In this and similar cases Mind takes— 
or seems to take—the initiative. We should, therefore, expect to find the 
thought slightly in advance, in point of time, of its material expression ; or, 
at least, not posterior in point of time. In such a case Mr. Frankland 
seems to consider himself justified in inferring that the mental operations— 
the nowmena, as he terms them—‘‘ underlie,” or are even identical with, the 
physical appearances. These are his words :—‘‘ According to the doctrine 
of Mind-Stuff, these feelings, or thoughts [in the mind of the person to 
whom the brain belongs], are the nowmena—the ‘ things-in-themselves "— 
which underlie the changes in the grey matter of the brain. What appears 
to an outside observer—or rather, what would appear to him were the skull 
‘transparent, as a change in the grey matter of the brain—is, in reality, a 
feeling or thought in the mind of the person to whom the brain belongs." 
I find it not easy exactly to define my own position with reference to 
this speculation. There is much in Mr. Frankland’s essay with which I 
heartily concur. He appears to me, if I may venture to say so, on the verge 
of truths which will lead him in a philosophical direction diametrically 
opposite to that which I understand him to be now pursuing. To such 
positions as these—that there are realities which underlie appearances— 
that physical science can never reveal to us these realities—that Psychology 
alone ean give us philosophical access to them—I assent ex animo. But I 
find it necessary to question the particular mode in which the writer pro- 
poses to make the transit from that which appears to that which is. 
In collating the sequence of ideas in the mind with the concomitant 
medullary changes, we have, I submit, two parallel series of phenomena 
between which we are incompetent to conceive of any necessary connection. 
I presume that this will be at once admitted as true in regard to any two 
parallel series of physical phenomena. In the field of physical science we 
know only, that events follow one another in an invariable sequence. We 
are not ‘entitled to affirm that the antecedent event causes, or produces, the 
