208 Transactio7is. — Misceltaneotis. 



among these, which constitute the whole content of physical science, there 

 exists a universe of realities inaccessible to physical science, on which the 

 possibilities of sensation are dependent. In the language of metaphysics 

 the question may be thus stated : — Does the phenojnenal world, or world of 

 appearances, correspond to and depend for its existence on a noumenal world, 

 or world of realities, wholly outside us ? The answer given by the majo- 

 rity of metaphysicians is, I believe, that there does exist such a world of 

 reahties, but that its nature must be for ever hidden from us. 



Physical science, they would say, investigates the properties of things 

 as they appear to us — investigates the outsides of things, so to speak ; but 

 things as they are in themselves, the inner nature or insides of things (though 

 we may be certain of their existence, whether intuitively or as a result of 

 legitimate inference), are inaccessible to human research. This I take to 

 be the doctrine of Kant, and also the doctrine of Herbert Spencer. Now, 

 the doctrine I wish to describe this evening, is partly in agreement with the 

 foregoing doctrine, and partly in disagreement with it. There is a universe 

 of realities, it af&rms, underlying the phenomena which it is the business 

 of physical science to investigate, but its nature is not wholly unknown to 

 us. For let us consider a particular section of physiological phenomena — 

 the phenomena of the human brain. In the changes which take place, 

 during life, in the grey matter of the brain, we have a field for physical 

 research. These changes belong to the world of phenomena — to the world 

 of " things as they appear to us." They may be described in the language 

 of physical science, and statements respecting them would resolve them- 

 selves, in last analysis, into statements of possibilities of sensation, and 

 relations among those possibilities, in the mind of a supposed observer. 

 But now, according to both the doctrines we are considering, this complex 

 of phenomena — this group of changes in the grey matter of the brain — 

 must have a complex of noumena, or " things-in-themselves," underlying it. 

 What is this complex of "things-in-themselves?" It is not an object of 

 physical research. Physical research stops at the changes in the grey 

 matter of the brain — stops at a group of appearances. What is the complex 

 of "things-in-themselves" which underlies these appearances? Now we 

 know, or at least have very strong ground for believing, that some of the 

 changes in the grey matter of the brain correspond to feelings or thoughts 

 in the mind of the person to whom the brain belongs. Accorcliny to the 

 doctrine of Mind-Stii.f, these feelings or thoughts are the noumena — the " things- 

 in-themselves " — ichich 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 



