And so Steiner carries our illustration to completion, and from his lecture his hearers have given us the following completed diagram, but at the point corresponding to the peach-blossom we find the human being:

What do we find corresponding to the colors of the twelvefold spectrum in the states of aggregation? Nothing less than the whole of nature, which we saw disappearing at both ends of the visible and coming together in the human being on the far side. The human being takes up what comes from both sides and is placed there at that point.²⁷

The form-giving forces come from below, from the ultra-U realm so to speak, and these, in the outer world, also give the human being its mental images. Insofar as form is incorporated within the human being, it does not belong to the sphere of consciousness. In embryo and infant, form is very plastic and related to formative forces. With advancing age formative forces withdraw progressively in proportion to the increase in conscious mental activity, even to the point that from and after death, in the discarnate state, these forces reveal themselves when form is completely dissolved.

What then comes from the top, the infrared realm? We know that physiologically we go through a certain interaction with outer nature to produce warmth, i.e., movement, voluntary and involuntary, which is a reflection of Will, both conscious and unconscious. Thus, just as the formative outer objects are akin to mental activity, so is heat related to our Will. We experience it in our Will. We see form in solid bodies, but what brings about the form is not there. Just as the soul-spiritual element is not within a corpse but has been in it, so is what determines form not within the object. If I perceive heat in nature, I experience the same thing that is active in me as Will. In the thinking and willing human, we have what meets us in outer nature as form and heat respectively. Of course, thinking and Will, form and heat, have all possible intermediate stages where they interpenetrate one another just as the realms of aggregation and colors do.

Both form and heat, in meeting within the human, must do so by disappearing from space. Nature shows us that when we think of her in relation to the human being, we must leave her.

But what does this mean mathematically? A linear series representing in sequence the states of aggregation may be considered as positive. Then what works into the human, both form and heat, must be put down as negative. Mental image in the human is related to outer world form as negative to positive. Photography gives an earthly representation of this.

Matter is characterized by the human as pressure effects. We saw this earlier as it related to our consciousness. Thus ideas about form (matter) must come into the picture as the opposite of pressure, namely, suction. Mental activity is suction. On the other hand, when positive outer heat enters the human, it is "sucked up," disappearing from space as a counter-image manifesting as Will. Debits remain debits although they are credits elsewhere. Human nature must be thought of as what continually sucks up and destroys matter.

Steiner observed that unfortunately modern physics had not in his day developed the concept of negative matter. After his death, science has developed experimentally the concept of antimatter (1 Brit 455). Though there certainly appears to be some relationship in concept, science still seems to me to deal with it only in the realm of matter (what can be observed through instrumentation). Will and thought phenomena have to be given negative values in relation to heat phenomena and form-giving forces.²⁸

Steiner demonstrated to his audience by experiment (placing different substances in the path of light to see what type of effect each blocks) that heat effects arise in the red portion of the spectrum, chemical (e.g., phosphorescence) in the violet, and light in the central portion. Under earthly conditions, a spectrum can only be presented as an image. The one we get is the well-known linear one formed from the circular one by making the circle larger and larger so that the peach-blossom disappears, with violet fading off to infinity on one side and red on the other. The forces that make the circle larger, and the line thus straight, are forces of form, including magnetic forces. And since these are everywhere active on Earth and within the spectrum it is necessary to represent it in a straight line, thus:

The denser matter is, the less light can pass through, and vice versa. Thus, dematerialization will appear as brightness and materialization as darkness. The light realm is just above that of heat. But we've seen that each realm gives a picture of the one above and is pictured by the one below. And recall also that there is a mutual interpenetration of qualities. This takes on a particular form in the heat realm. There dematerialization works down into heat from above, while the materialization tendency works up into it from below (see arrows in the diagram).

Heat is thus conceived of as involving a living weaving—as against the concept of the mechanical theory of heat involving atoms and molecules in a closed space colliding with each other. Heat is indeed motion, but in the sense that there is a tendency to create material existence and then let it disappear again.²⁹ This is why we need heat in our organism, simply to change continuously the spatial into the nonspatial. Heat is what makes it possible for me to deal with things in space while forming ideas outside of space. Thus within me there is intensive motion continually alternating between pressure effects and suction effects, pictured below:

Thus, heat must be conceived as intensive motion, as an alternation between spatial pressure and spaceless suction, but in such a way that neither pressure nor suction is spatially manifested. To comprehend it, we must entirely leave the material world and with it three-dimensional space. It is a vortex continually manifesting in such a way that what appears physically is annihilated by what appears as the spiritual—a continuous interplay—a sucking up of what is in space by the entity that is not. Such is the figurative Imagination.

Another widely applied "scientific" conceptual term is called the "heat conduction principle." It is of practical utility. But Steiner says it does not exist in fact, nor is it in keeping with the more important phenomena, for what happens in what we call heat conduction is not "conduction" in any proper sense. He compares it to placing a row of boys on a metal rod that is heated at one end. As the rod becomes hot the boys cry out, first one, then the next, and so on. But it would never occur to us to say that what we heard from the first boy was conducted to the second, the third, and so on. When physicists apply heat and perceive it moving down the rod, they are really observing how the body of the rod reacts, one part after another, to the warmth being, just as the boys standing on the rod yell out. You cannot say the yells are "conducted."

Returning to the prior discussion, the heat, light and chemical effects in the spectrum can be initially portrayed in the following line:

But if we want to construct a picture of this spectrum, we must not think of light, heat and chemical effects as stretched out in a straight line, but rather as shown in the following diagram:

Thus, it is not possible to remain in the plane of light effects if we wish to symbolize either the heat or chemical effects. We have to move out of this plane, leaving only the light effects in it. But if we reserved the positive sign for heat and the negative for chemical effects, we cannot use either of these for light effects. We have to use imaginary numbers. In essence, these involve the square root of a negative number.³⁰