302 THE GROUNDWORK OF SCIENCE

We have that experience in every movement of our

own frame, either in its change of place as a whole, or in the

movements of its various parts. Every breeze which sways

the smallest branches of a tree, or but makes its leaves to

vibrate, reveals it to us. Every cloud we see blown across the

sky and every dust-eddy gives us that experience. By move-

ments, the dawning human intellect is first aroused to activity

as the infant notices the movements and gestures of those

around it, and the movements it can itself impart to objects

it begins to grasp or kick against. In boyhood the throwing

of stones or balls, the movements of marbles, the spinning of

tops, and all games up to football and cricket, continually

reinforce the experiences gained at the dawn of mental

life.

Indeed, the motion of solid bodies is the most primitive,

most constant, and most universal of all our experiences.

Thus the abstract idea " motion " comes most readily before

the mind, and at first it seems that nothing can be easier

than to understand the movements of bodies, and what

is meant by the term denoting that idea. And for most

purposes of science an apprehension of that ordinary meaning

is amply sufficient ; but here, including as we do, and must

do, in our purview the science of sciences, we think it incum-

bent on us to endeavour to draw out more carefully the

significance of the idea we are now concerned with.

When we proceed to study our conception of motion,

various difficulties and problems present themselves for

solution. Obviously, any given object, e.g., a feather blown

by the wind, must be one and the same thing when so

propelled as when resting on the ground. Nevertheless, it is

no less obviously in a different state when in motion from

that in which it is when at rest. What, then, do we really

mean by its " motion " ? As we have said, that term is

abstract, and therefore what it denotes cannot really exist in

the concrete ; yet there must be some concrete reality which

is the foundation of that abstraction.

Now in all our experience, whatever has moved has

always moved away from the vicinity of something and

in the direction of something else. This uniform experience

must of course prevent us from being able to imagine

motion taking place in any other mode. But can we conceive

of its taking place otherwise? To us it seems perfectly

clear that motion must be, not only in some definite direc-

tion at each instant, but also from one entity and towards

another.

Some of my readers may think that were all objects save

one annihilated, that one might nevertheless traverse space.

Now if space were a real permanent existence, then any

object moving through it, would of course proceed from the

vicinity of one part of it to the vicinity of another portion of

space ; but if, as we believe to be the case, there is no such

thing as " space " at all, then evidently no object could

traverse it, for no object could traverse that which has no

existence.

But if space does not exist, it is evident that the universe,

considered as one whole, must be absolutely incapable of

motion, save internally. Such is the case, since the universe

must contain everything, or it would not be the universe ;

and therefore there can be nothing for it to approach or

recede from.

Thus motion is, or includes, a relation of one body to

another or to other bodies. But can this be all ? Can there

be nothing more objective in motion ?

We have seen the widespread tendency which exists to

speak of the physical energies as if they were material

substances. Is this the result of a pure delusion, or can

there be a true and valid objective foundation for it?

Evidently motion, heat, light, etc., cannot be so many

We have that experience in every movement of our

own frame, either in its change of place as a whole, or in the

movements of its various parts. Every breeze which sways

the smallest branches of a tree, or but makes its leaves to

vibrate, reveals it to us. Every cloud we see blown across the

sky and every dust-eddy gives us that experience. By move-

ments, the dawning human intellect is first aroused to activity

as the infant notices the movements and gestures of those

around it, and the movements it can itself impart to objects

it begins to grasp or kick against. In boyhood the throwing

of stones or balls, the movements of marbles, the spinning of

tops, and all games up to football and cricket, continually

reinforce the experiences gained at the dawn of mental

life.

Indeed, the motion of solid bodies is the most primitive,

most constant, and most universal of all our experiences.

Thus the abstract idea " motion " comes most readily before

the mind, and at first it seems that nothing can be easier

than to understand the movements of bodies, and what

is meant by the term denoting that idea. And for most

purposes of science an apprehension of that ordinary meaning

is amply sufficient ; but here, including as we do, and must

do, in our purview the science of sciences, we think it incum-

bent on us to endeavour to draw out more carefully the

significance of the idea we are now concerned with.

When we proceed to study our conception of motion,

various difficulties and problems present themselves for

solution. Obviously, any given object, e.g., a feather blown

by the wind, must be one and the same thing when so

propelled as when resting on the ground. Nevertheless, it is

no less obviously in a different state when in motion from

that in which it is when at rest. What, then, do we really

mean by its " motion " ? As we have said, that term is

abstract, and therefore what it denotes cannot really exist in

the concrete ; yet there must be some concrete reality which

is the foundation of that abstraction.

Now in all our experience, whatever has moved has

always moved away from the vicinity of something and

in the direction of something else. This uniform experience

must of course prevent us from being able to imagine

motion taking place in any other mode. But can we conceive

of its taking place otherwise? To us it seems perfectly

clear that motion must be, not only in some definite direc-

tion at each instant, but also from one entity and towards

another.

Some of my readers may think that were all objects save

one annihilated, that one might nevertheless traverse space.

Now if space were a real permanent existence, then any

object moving through it, would of course proceed from the

vicinity of one part of it to the vicinity of another portion of

space ; but if, as we believe to be the case, there is no such

thing as " space " at all, then evidently no object could

traverse it, for no object could traverse that which has no

existence.

But if space does not exist, it is evident that the universe,

considered as one whole, must be absolutely incapable of

motion, save internally. Such is the case, since the universe

must contain everything, or it would not be the universe ;

and therefore there can be nothing for it to approach or

recede from.

Thus motion is, or includes, a relation of one body to

another or to other bodies. But can this be all ? Can there

be nothing more objective in motion ?

We have seen the widespread tendency which exists to

speak of the physical energies as if they were material

substances. Is this the result of a pure delusion, or can

there be a true and valid objective foundation for it?

Evidently motion, heat, light, etc., cannot be so many