THE PRESIDENTIAL ADDRESS 5 
starting-point, postulated the existence of ‘ matter ° to provide such 
starting-points. But the existence of this matter was a pure hypo- 
thesis; and matter is in actual fact as unobservable as the ether, 
Newtonian force, and other unobservables which have vanished 
from science. Early science not only assumed matter to exist, but 
further pictured it as existing in space and time. Again this 
assumption had no adequate justification ; for there is clearly no 
reason why the whole material universe should be restricted to the 
narrow framework along which messages strike our senses. To 
illustrate by an analogy, the earthquake waves which damage our 
houses travel along the surface of the ground, but we have no 
right to assume that they originate in the surface of the ground ; 
we know, on the contrary, that they originate deep down in the 
earth’s interior. 
The Newtonian mechanics, however, having endowed space and 
time with real objective existences, assumed that the whole universe 
existed within the limits of space and time. Even more character- 
istic of it was the doctrine of ‘ mechanistic determinism,’ which 
could be evolved from it by strictly logical processes. This reduced 
the whole physical universe to a vast machine in which each cog, 
shaft, and thrust bar could only transmit what it received, and wait 
for what was to come next. When it was found that the human body 
consisted of nothing beyond commonplace atoms and molecules, 
the human race also seemed to be reduced to cogs in the wheel, and 
in face of the inexorable movements of the machine, human effort, 
initiative, and ambition seemed to become meaningless illusions. 
Our minds were left with no more power or initiative than a sen- 
sitised cinematograph film; they could only register what was 
impressed on them from an outer world over which they had no 
control. 
Theoretical physics is no longer concerned to study the Newtonian 
universe which it once believed to exist in its own right in space and 
time. It merely sets before itself the modest task of reducing to 
law and order the impressions that the universe makes on our senses. 
It is not concerned with what lies beyond the gateways of knowledge, 
but with what enters through the gateways of knowledge. It is 
concerned with appearances rather than reality, so that its task 
resembles that of the cartographer or map-maker rather than that of 
the geologist or mining engineer. 
Now the cartographer knows that a map may be drawn in many 
ways, or, as he would himself say, many kinds of projection are 
available. Each one has its merits, but it is impossible to find all 
the merits we might reasonably desire combined in one single map. 
It is reasonable to demand that each bit of territory should look its 
proper shape on the map; also that each should look its proper 
