More Objections

Sight and Touch Alone Cannot Convey the Idea of a Vacuum

The following produce the only perceptions which we can judge of the distance:

• the angles of the rays of light flowing from them, forming with each other,
• the motion required in the eye, in its passage from one to the other, and
• the different parts of the organs affected by them.

Each of these perceptions are simple and indivisible.

They can never give us the idea of space.

Two men are floating in the air.

One man moves his arm around without hitting anything tangible.

Another man moves his arm around and hits an object.

His arm leaves it, moves again, and hits another object.

The difference in these 2 cases is merely in the perception of those objects.

The sensation arising from the motion is the same in both cases.

That sensation cannot:

• give us an idea of space when there is no other perception, nor
• give us more of that idea of space when mixed with the touch of tangible objects, since that mixture does not change the space.

Motion and darkness give us no idea of vacuum.*

In Our Experience, Free Motion Happens in Darkness

We falsely associate the idea of a vacuum with darkness and free motion because there is:

• a close relation between free motion and darkness, and
• a real space between visible and tangible objects.

1. Two visible objects in utter darkness makes us see a gap between them, which our minds can fill with objects that can give us a true idea of space.

The sensation of motion is likewise the same when there is nothing tangible between two bodies.

2. Two green balls have a gap between them filled with two more balls and are placed in the same way as two yellow balls.

Our senses will see that the two yellow balls can receive the same space without us touching them.

Similarly, we can detect the space between those yellow balls when we run our hand between them and feel no objects other than those two.

In other words, without changing the 2 yellow balls:

• our imagination can convert an invisible distance into a visible one, and
• our sense of motion can convert an intangible distance into a tangible one.

3. These 2 kinds of distance have nearly the same effects on every natural phenomenon.

All qualities, such as heat, cold, light, attraction, etc. reduce in proportion to the distance.

This exposes 3 relations between that distance which conveys the idea of a space, and a vacuum.

a. The distant objects affect the senses in the same way, whether separated by space or a vacuum.

b. The second kind of distance can receive the first kind of distance.

c. A space and a vacuum equally reduce the force of every quality.

These relations between a space and a vacuum is why:

• the one has so often been taken for the other
• we imagine we have an idea of space without the idea of any visible or tangible object.