w and can know nothing; and in affirming the existence of such
substrata we are making a supposition we can not possibly verify. The
ultimate datum of speculative philosophy is not "_I think_," but simply
"_Thoughts or feelings are_." The belief in a permanent subject or
substance, called matter, as the ground and plexus of physical
phenomena, and of a permanent subject or substance, called mind, as the
ground and plexus of mental phenomena, is not a primitive and original
intuition of reason. It is simply through the action of the principle of
association among the ultimate phenomena, called feelings, that this
(erroneous) separation of the phenomena into two orders or
aggregates--one called mind or self; the other matter, or not
self--takes place; and without this curdling or associating process no
such notion or belief could have been generated. "The principle of
substance," as an ultimate law of thought, is, therefore, to be regarded
as a transcendental dream.

But now that the notion of _mind_ or _self_, and of _matter_ or not
_self_, do exist as common convictions of our race, what is philosophy
to make of them? After a great many qualifications and explanations, Mr.
Mill has, in his "Logic," summed up his doctrine of Constructive
Idealism in the following words: "As body is the mysterious _something_
which excites the mind to feel, so mind is the mysterious _something_
which feels and thinks."[228] But what is this "mysterious something?"
Is it a reality, an entity, a subject; or is it a shadow, an illusion, a
dream? In his "Examination of Sir Wm. Hamilton's Philosophy," where it
may be presumed, we have his maturest opinions, Mr. Mill, in still more
abstract and idealistic phraseology, attempts an answer. Here he defines
matter as "_a permanent possibility of sensation_,"[229] and mind as "_a
permanent possibility of feeling_."[230] And "the belief in these
permanent possibilities," he assures us, "includes all that is essential
or characteristic in the belief in substance."[231] "If I am asked,"
says he, "whether I believe in matter, I ask whether the questioner
accepts this definition of it. If he does, I believe in matter: and so
do all Berkeleians. In any other sense than this, I do not. But I affirm
with confidence that this conception of matter includes the whole
meaning attached to it by the common world, apart from philosophical,
and sometimes from theological theories. The reliance of mankind on the
rea