8 
Transactions Texas Academy of Science. — 1906. 
tain that sensations rightly studied tell us what matter is. Known 
directly and indirectly as effects of matter working on our senses, 
sensations show matter to be a vastly complicated system of active 
causes, occupying space— that, and nothing more. Each material 
object is thus known to be a group of forces, more or less complicated 
in their interplay, and varied as to their constituent elements. The 
forces constituting a living cell are very varied in kind, and compli- 
cated in interplay, as compared with those composing an equal vol- 
ume of hydrogen gas; but complicated and varied forces are forces 
none the less. Moreover, all kinds of matter have one quality in 
common, the forceful defence of the space they occupy. This is 
called their resistance or impenetrability. Everything material op- 
poses force to attempted encroachment on its space, and, unless given 
room elsewhere, absolutely prevents its entire appropriation; though 
all the forces of the universe pressed upon a single drop of water, 
it could not be annihilated. Thus impenetrability is the active de- 
fense of space. The fundamental constituent of matter is force. And 
other constituents are the chemical, electrical and physical activities 
whose effects are familiar. Nor need philosophers deny that matter 
is made up of molecules and atoms, or of electrons even, provided 
always these smaller and smaller particles are admitted to be bundles 
of forces, occupying less and less extended allotments of space. 
Where this view departs from that of common sense it is simpler, 
that is all. Common sense says matter is blue, sweet, soft, etc. No, 
say the philosophers, these are effects, not properties. Again, com- 
mon sense says, and here with a shrill insistence, force is not matter, 
but in it. No, say the philosophers, there is no need of complicating 
with an unmeaning distinction. Force, activity, achievement, that 
is all that there is to matter. As Heracleitus said 2,500 years ago, 
Panta rei, flowing, change, doing is all. 
Beyond question the blind forces of our nature strongly incline 
us to ask for more. But in obeying this prompting we are but wor- 
shiping an idol of the tribe, a fallacy patent enough as soon as the 
nature of the mind is understood. The insistence on something more 
than force in outer objects registers the triumph of the imagination, 
a blind faculty, as Kant rightly called it, unaware of its own contents 
and of their significance, over clear-sighted and self-critical reason. 
Everything we talk of and think about, including matter, is identi- 
fied, when necessary, and mentally dealt with, by means of its picture 
stored away in the imagination, which appears automatically when 
its aid is required. Without such counterfeit presentments, the 
mind could not make a beginning of dealing with the objects about 
it, for their names are not pasted upon their backs, and besides, 
