413 
immense imlfrfl* fw- P, 0 '" 1 ? of s P-->“, introduce an 
i imense number of hypothetical or imaginary atoms, not perceived 
y e senses, to fill up the intervals between the bodies we can see 
or occupy the spaces beyond them ? Thus, if the solar system is 
moving m a known direction, we may conceive the whole of the 
aei within the orbit of Neptune either to move or not to move 
along with it. _ In the latter case the visible parts of our system 
are moving with reference to the invisible, and as the bulk of 
these last is immensely superior, they become the natural standard 
of reference. But it all be conceived to move together, our notions 
of immovable space will be drawn from these interstices, now 
supposed to be. ever changing, of our own system. And if our 
whole system, visible and invisible, including all from which our 
notions of space are borrowed, is to be reckoned in motion, it must 
be in relation to some equal or larger visible and invisible system, 
faraway. And this is plainly a new relation, or set of almost 
infinite relations. 
30. Absolute Space and Motion is thus a rainbow, receding ever 
before us. The moment we strive to grasp it, it eludes us and 
disappears. If some one body somewhere were absolutely at rest 
found" 114 I " iVer ^ SUre ° f the faCt> or learn ' rIlere could b « 
31. Newton remarks further : 
‘There is only one real circular motion of any one revolving body, cor- 
responding to one power of endeavouring to recede from the axe of motion 
as its proper and adequate effect. But relative motions in one and the same 
body are innumerable, according to the various relations it bears to external 
bodies. Relative quantities are not the quantities themselves, whose names 
they bear, but sensible measures of them, which are commonly used instead 
of the measured quantities themselves. And if the meaning of words is to 
be determined by their use, then, by the names space, place and motion, 
their measures are properly to be understood, and the expressions will be 
unusual and purely mathematical, if the measured quantities themselves are 
meant ; upon which account they strain the sacred writings, who there in- 
terpret the words for the measured quantities. Nor do these less defile the 
purity of philosophical truths, who confound the real quantities themselves 
with their relations and vulgar measures. It is, indeed a matter of great 
difficulty to discover and distinguish the true motions of particular bodies 
from the apparent, because the parts of that immovable space in which the 
motions are performed, do by no means come under our senses. Yet it is 
not altogether desperate. For we have some arguments to guide us, partly 
from the apparent motions, which are the differences of the true, and partly 
from the forces which are the causes and effects of the true motions.” 
32. Here Newton repels and refutes that charge of scientific 
VOL. xi. 2 G 
