1803.] 
of all material fubftances. If {pace be no 
fubftance, matter alfo is w#real; and both 
are mere relations ‘of our perceptions, as 
are time and motion. But that {pace is not 
a fubftance, is admitted ; and has, I think, 
been proved, independently of admiffion. 
‘The non-exiftence of matter is merely the 
conclufion, the neceffary conclufion. 
But were no arguments advanced again 
the exiftence of matter? My opponent, al- 
molt in the fame breath, maintains that 
none were advanced, and quotes two. 
The frfi of thefe is, ‘* that mind and 
matter have no common principle of action.” 
New, this is exclufive of the common or 
mixt hypothefis, which cannot coniift 
with the truth of the affertion. 
The fecond is, ‘* mind, of the exiffence. 
of which we cannot doubt, will account for 
all ideas and fenfations ; and therefore no 
other folution can pbilofophically be adopt- 
ed.’ And this is exclufive of the fimple 
hypothefis of matertalifn. 
But my opponent fays, that the firft af- 
fertion ‘* is contradicted. by hourly expe- 
rience*.’ But is not this manifeltly a 
begging of the queftion; ‘ a claim of 
grant of the very point in difpute.”’ If 
we bave hourly experience that matter adts 
on mind, how idly is he attempting to 
prove, or I to difprove, wnat this -hourly 
experience has perpetually and irrefiitibly 
proved to ali, 
_ But let us enquire, what we do expe- 
rience. 
We certainly experience that our own 
mind aéts; we as certainly experience 
that our mind is fubjeét to influences 
which do not originate in itflf, but aét 
upon it. Each individual is therefore cer- 
tain, that he is zot the fole being, but that 
other minds exist, whether any thing but 
mind exilts or not. 
But that mind may and muft have a 
common principle of aétion on mind cer- 
tainly and intuitively appears. Things 
that have a common nature muft have a 
common and reciprocal principle of ac- 
tion. Mind conlequently may produce, 
and is naturally adequate to produce, all 
effects which can take place in mind. 
It remains to enquire on this head, 
whether any thing but mind caz produce 
thefe effects. If matter caz produce them, 
it muft be by virtue of fome common 
principle. Now, have we evidence of 
fuch principle ; or, have we not rather all 
poffible evidence againft it? 
My opponent fuppoles that matter * dy 
its prefencet+”’ can and does excite percep- 
ree eee TiPuged 
* Monrtruty Mac. No. 102. 
Reply in Vindication of the Berkeleian Syftem. 
523 
tion; and that this isan effential property 
of matter derived from the wiil of Deity. 
But the effential properties muf& be fuch 
as refult from the zature of a being, not 
fuch as are fuperadded, even if ‘this could 
without contradiction be fuperadded.’ And 
what.do we find in this fuppofed exiftence? 
‘¢ Matter,’ by which it can be inherent 
in it to excite perception. 
My opponent agrees with me, that ** zo 
definition can be given of matter and {pirit 
(or, as I leis equivocally choofe to fay, 
mind) which can include both under one 
commonnuame;* and why, but for this rea- 
fon——that they cannot be included under 
one common nature? But my opponent, 
(and his hypothefis required it) attempts 
to include in matter thofe very properties 
and powers, by the privation of which 
Newrron, and pnilofophers in general, 
admitting its exiftence, have diftincuifhed 
it from mind. He admits, with Ariftotle, 
that matter has figure: but he admits it 
for this caufe only, that by means of fi- 
gure it acts on our fenfes. In doing this, 
he aflumes the very point in difpute ; for, 
unlefs our fenfes are exerciled by means of 
material organs, material figure can have 
no effeét in producing fenfation. It would 
have been better furely to have afferted, 
that matter poffefles figure, becaufe folid 
extenfion circum/cribed in {pace neceflarily 
implies fome determinate figure. The 
only real proof, therefore, that figure is 
other than a phenomenon of perception muft 
bedrawn from previoufly eitablifhing, that 
{pace is a real {ubftance, and is occupied by 
folid extenficn. 
My opponent next afferts, that Plato is 
not juftified in {uppofing matter to be fenfe- 
lefs ; and the only realon he gives is this, 
that ‘the living brain is figured, and not 
Jfenfelefs,> as being “ the organ of percep- 
tion.’ But it isone thing to be the organ 
cr infirument of perception and fenfation, 
and another to perceive and feel. The 
whole mixt hypothefis pre-fuppofes this 
diftinétion : and even in the material, per. 
ception, commonly, as, by my opponent, 
is fuppofed to lodge in the brain; and the 
organs of perception not to be themfelves 
percipient. But has not my opponent 
feen, that brain and body and organs, in the 
material fenfe, can none of them be fup- 
pofed or admitted to exilt, unlefs the exif- 
tence of matter be firft proved, or on rea- 
fonable grounds fuppofed ? 
He goes on to objeét to the Newtonian 
definition, that matter is zzert; and fup- 
pofes that ‘the rays of heat and light or 
YP 324. 
3 ¥ gravitation 
