The Other Qualities of our Idea of Space and Time

Time is Sensible Only with Changes

Impressions always precede ideas.

Every idea first appears as a correspondent impression.

However, many of our ideas are so obscure that it is almost impossible for the mind to tell their nature and composition.

I apply this principle to discover the nature of our ideas of space and time.

When I open my eyes, I see many visible bodies.*

When I close my eyes, I acquire the idea of space* from the distance between these bodies.

Every idea is derived from some impression exactly similar to it.*

The impressions similar to this idea of space must be visual sensations.

The table before me gives me the idea of [physical] space.

This idea of [physical] space represents some impression [of physical space] appearing to my senses now.

But my eyes only convey the impressions of points.

If I could see closer, I would see new points.

Suppose that in this table, the points were purple.

Every repetition of that idea, we would:

• place the points in the same order with respect to each other
• bestow a purple colour on them, which is the only color we know.

But after experiencing other colours of green, red, white, black, etc, and finding a resemblance in the disposition of those points, we:

• omit the peculiarities of colour, as far as possible, and
• found an abstract idea merely on how they look.

The abstract idea is not hindered from representing touch and sight, because of their resemblance, even when:

• the resemblance is carried beyond the sense objects
• impressions of touch are similar to those of sight in the disposition of their parts.

All abstract ideas are just particular ideas, considered in a certain light.

But since they are annexed to general terms, they are able to represent a variety of objects

What is Time?

The idea of time is derived from the succession of our:

• perceptions,
• ideas and impressions,
• impressions of reflection, and
• sensations.

This abstract idea of time has more variety than the idea of space.

Yet it is represented in the imagination by some specific individual idea of a determinate quantity and quality.

We get the idea of space from the disposition of visible and tangible objects.

We create the idea of time from the succession of ideas and impressions.

It is impossible for time to appear alone.

A man in a sound sleep, or strongly occupied with a thought, is insensible of time.

The same duration appears longer or shorter to his imagination, depending on how fast or slow his perceptions succeed each other.

Malezieu has remarked that our perceptions have certain bounds fixed by the mind’s original nature and constitution.

Beyond those bounds, no influence of external objects on the senses can hasten or retard our thought.

For example, if you wheel around a burning coal rapidly, it will appear as an image of a circle of fire.

• There will seem no gap of time between its revolutions because it is impossible for our perceptions to succeed each other as rapidly as its rotating motion.

Wherever we have no successive perceptions, we have no notion of time, even though there is a real succession in the objects.

Thus, time:

• cannot appear to the mind alone or through a steady unchangeable object, and
• is always discovered through some perceivable succession of changeable objects.

Therefore, time or duration consists of different parts.

• Otherwise, we could not conceive a longer or shorter time.

These parts are not co-existent, because the co-existence of parts:

• belongs to space, and
• distinguishes it from time.

Since time is composed of parts that are not coexistent, an unchangeable object producing only coexistent impressions cannot give us the idea of time.

Consequently, idea of time:

• must be derived from a succession of changeable objects
• in its first appearance, can never be severed from such a succession.