914 Transactions.— Miscellaneous, 
Thomson, which makes all the atoms of ordinary matter, and all the par- 
ticles of which the ether is composed, to consist of a rotational motion in 
an incompressible frictionless fluid? The stoppage of the vortex-motion 
would be the obliteration of both atoms and ether—the annihilation of the 
sensible universe. The perfect fluid at rest would be, on my view, & mere 
nullity. No noumenal existence would correspond to it, and it would, in 
fact, merely represent the potentiality of massiveness among feelings. 
Two other identifications will at once suggest themselves, and may be 
relied on with greater confidence than any of the three preceding ones: 
First, the causal relations among elements of feeling will have their counter- 
parts in the causal relations among motions of matter, i.e., they will have 
their counterparts in the dynamical laws of the universe. And secondly, 
the relations of synchronism among elements of feeling will have their 
counterparts in the relations of synchronism among the motions of matter, 
i.e., they will have their counterparts in the space-relations of the universe. 
Certain passages in Herbert Spencer’s ‘‘ Principles of Pyschology” seem to 
indicate that he entertains a similar belief. 
And now, one more thing follows. The nexus of causation which 
obtains among the feeling-elements, or Mind-Stuff units, i.e., among the 
elements of the noumenal world, must be at least as complex as the corre- 
sponding nexus which obtains among the motions of matter, i.e., among the 
elements of the phenomenal world ; and it may be indefinitely more so. For 
the phenomenal world depends for its existence on the noumenal world, and 
is in fact only a particular aspect of the latter—that aspect, namely, which 
the noumenal world presents to its own most complex strands, the percipient 
beings that grow up in its bosom. Nor can the elements of the phenomenal 
world derive any complexity from the interaction of the noumenal elements 
which they represent with the complex structure of the precipients. For it 
is the especial triumph of the mechanical theory of the universe to have 
eliminated all these complexities, and referred the affections of the various 
senses to the same source. Thus the sensations of light and warmth we 
receive from a fire, are both referred to the radiant energy of the ether 
which intervenes. between the fire and ourselves. Hence we may be certain 
that the nexus of causation in the noumenal world is at least as complex as 
the dynamical nexus of the phenomenal world. But it may be indefinitely 
more so, There may be many causal relations in the noumenal world which 
have no types in the phenomenal world, though we may be certain that every 
dynamical relation in the phenomenal has its anti-type in the noumenal 
world. The phenomenal world is a projection, so to speak, of the noumenal 
world on the plane of observation, and much complexity may be lost in the 
process of projection. In the same way the space-relations of the pheno- 
