The Aethereal Elements and Their Qualities

by Rene Descartes

The philosophers assure us that above the clouds there is an aethereal air much subtler than ours.

That air is not composed of vapors of the earth, but is an element in itself. Above this air there is another, much subtler body, which they call the element of fire.

These two elements are mixed with liquids and solids of all the inferior bodies. This aethereal air and fire fill the in-between spaces* among the parts of the real air that we breathe. These bodies, interlaced with one another, then compose a real solid mass.

*Superphysics Note= The previous chapter explained that the aether had bodies within it. This chapter explains what those bodies are, as aethereal air and aethereal fire

Athereal Fire

My idea is that the first element is an aethereal fire. It is the most subtle and penetrating fluid in the universe. As a liquid, its parts are smaller and move much faster than those of other bodies.

This aethereal fire has no determinate size or shape.

Or rather, in order not to be forced to admit any void in nature, I do not attribute to this first element parts having any.

The impetuosity of their motion causes them to be divided by collision with other bodies. Its parts:

• change shape at every moment to accommodate themselves to the shape of the places they enter
• can go into any passage regardless of narrowness
• can penetrate the and fill the gaps in other bodies easily

Athereal Air

The second element is aethereal air. It is also a very subtle fluid compared to the third. But compared to fire, it has some size and shape to each of its parts. They are all round and joined together like grains of sand or dust.

Thus, they cannot arrange themselves so well, nor so press against one another that there do not always remain around them many small intervals into which it is much easier for the first element to slide than for the parts of the second to change shape expressly in order to fill them.

This air cannot be so pure anywhere. There is always some fire with it.

Athereal Earth

The third and last element is aethereal earth. Its parts are much larger and move as much less swiftly compared to air as those of air are slower than those of fire.

It is one or more large masses, of which the parts have very little or no motion that might cause them to change position with respect to one another.

I do not use the qualities called “heat,” “cold,” “moistness,” and “dryness,” as do the philosophers.

The difference between them and the other bodies that the philosophers call “mixed” or “composite” consists in the forms of these mixed bodies always containing in themselves some qualities that are contrary and that counteract one another, or at least do not tend to the conservation of one another, whereas the forms of the elements should be simple and not have any qualities that do not accord with one another so perfectly that each tends to the conservation of all the others.

The parts of aethereal fire move extremely fast. They are so small that no other bodies can stop them. Beyond that, they require no determinate size or shape or position.

The parts of air have a middling motion and size. Their motion and size can be decreased or increased. Thus, they always remain balanced in that same middling condition.

Earth has parts so large or so joined together that they have the force always to resist the motions of the other bodies.

Flame, for example, have parts that move very fast and have some size. But they cannot last long without being corrupted. They give their force to other bodies, causing their motion to reduce.

The violence of their agitation, causes them to break upon themselves against the bodies they encounter and lose their size.

Thus, gradually, they reduce themselves to the Earth element, or the Air, or remain as Fire.[22]

The aethereal air and earth are less similar to the grosser air we breathe or to this earth on which we walk. Instead, all the bodies we see are mixed and subject to corruption.

In the universe, the elements have no places that are particularly destined for them where they can be perpetually conserved in their natural purity.[23]

On the contrary, each part of matter always tends to be reduced to one of their forms. After being reduced, they never tend to leave that form. Hence, even if God at the beginning had created only mixed bodies, nevertheless since the world began all these bodies could have had the chance to leave their forms and to take on those of the elements.

Thus:

• all the bodies that are large enough to be counted among the most notable parts of the universe each have the form of only one of these elements alone
• mixed bodies can only appear on the surfaces of these large bodies

There are mixed bodies that are formed from the interaction between the three elements.

The universe only has three kinds of parts that are large enough:

1. The sun and the fixed stars as the first sort
2. The heavens as the second
3. The earth with the planets and the comets as the third

The stars are made up of pure Fire. The heavens are made up of pure Air. Planets and comets are made up of Earth.

• I link the planets and the comets with the earth because they, like she, resist light and reflect its rays.
• The nature of stars is totally contrary to that of planets because the action alone of their light shows that their bodies are of a very subtle and very agitated matter.
• The aethereal heavens cannot be perceived by our senses. They have a middle nature between the luminous bodies whose action we perceive and that of the solid and heavy bodies whose resistance we perceive.
• Finally, we do not perceive mixed bodies in any other place than on the surface of the earth.[24]

Thus, the mixed bodies are not only in the air we breathe, but also in all the other composite bodies right down to the hardest rocks and the heaviest metals.

• The latter are parts of the element of air mixed with those of earth.
• Consequently, they are also parts of the element of fire, because they are always found in the pores of the element of air.

These three elements are mixed with one another in all bodies. Only those of the Earth element compose the bodies we see, because of their size or the difficulty they have in moving.

The parts of aethereal fire and air are so subtle that they cannot be perceived. One may think of all these bodies as sponges. They have many small holes always full of air or water.