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Wisconsin Academy of Sciences , Arts and Letters. 
IV. 14. Is time such a relation that it would not exist if there were 
no mind to number continuous change and refer it to some measure? 
That seems to be necessary deduction from our definition of time. 
VI. 1. Time, like every other continuous quantity, cannot consist of 
indivisible units, any more than a line can consist of successive points. 
L.. VI. 6. All changes, like time their number, are, potentially, divisible 
ad infinitum. From this is deduced the very suggestive principle, that no 
change or motion can possibly be instantaneous. 
In Aristotle’s De Sens, Chapt. VI, he applies this principle to show the 
progressive motion of light. 
VII. 1. Wherever there is change, or motion, there must be an ante¬ 
cedent, efficient cause, which itself may be something moved or changed. 
And so we may make a regress indefinitely; but such a series cannot be 
infinite. 
I do not propose to follow the metaphysical proof of this proposition, 
but only to note the result, viz., that in physics a first moving cause which 
is not itself subject to change must, according to principles of reason, be 
assumed to exist. We shall not reach that first cause, perhaps, by regress 
through the chain of changes; for these are discovered by the senses; but 
this first cause is not so discoverable, but is an intelligible principle, neces¬ 
sary in accounting for change, and known with absolute certainty to exist. 
VIII. 1. Motion, change, cannot be annihilated. Nature is orderly, sub¬ 
ject to law, and the law of continuity of force canies on successive 
changes in the indefinite extension of time. 
VIII. 5. Let us consider further the prime mover. It may indeed, act 
hrough many media, just as a man may impel a stone through the media of 
his cane, his hand, etc.; but it is impossible to recede in such a chain through 
an absolute infinity of links. The first mover, then, is self-moved. It does 
not constitute one of the chain of links; for those are sensible, the prime 
mover is purely intelligible. It is itself immutable. Everything which 
is mutable, is also divisible. But the prime mover is one and indivisible. 
VIII. 6. It never changes, but the things which are moved change 
their relations to it, as it does to them. Here I observe, in passing, that 
the changed relations of Deity to the world of finite beings, according to 
this principle, are based on changes in the things which belong to time. 
This prime mover is eternal. For motion has neither beginning nor end. 
It has absolute unity. There may, indeed, be many motors which are 
immutable; but if they come into being, or cease to be, there must be a 
cause of that, as of any other change. Thus, we are carried back again to 
the eternal, primal mover. All change is, in ultimate analysis, reducible 
to one continuous motion. Therefore the first cause is one only. All 
living things may be called self-moved; but they are also changeable and 
conditioned by external things. “ 
Concluding this too brief review of Aristotle’s fundamental physical 
principles, I will try to state what laws of nature now empirically estab- 
