Naturally, the discussion then took off like wildfire. Toward the end of it, Rappaport suddenly rose with “one more hypothesis.” It was so original that I present it here. He defended the thesis that the difference between “artificial” and “natural” was not entirely objective, not an absolute given, but a relative thing and dependent on the cognitive frame of reference. Substances excreted by living organisms in the course of their metabolism we considered to be natural products. If I ate a great quantity of sugar, its excess would be eliminated by my kidneys. Whether the sugar in the urine was “artificial” or “natural” depended on my purpose. If I ate so much sugar intentionally, in order to eliminate it, knowing the mechanism involved and able to predict the effects of my action, the sugar would be “artificially” present; but if I ate it because I had a craving for it, and for no other reason, its presence would be “natural.” One could demonstrate this. If someone examined my urine and if I had arranged this with him accordingly, the presence of sugar which he would discover could acquire the meaning of an informational signal. The sugar might signify, for instance, “yes,” and the lack of sugar “no.” This process of symbolic signaling would be as artificial as could be, but only between the two of us. Whoever did not know of our arrangement would learn nothing of it from an examination of the urine. So, then, in Culture as well as in Nature only the “natural” phenomena existed “really and truly”; the “artificial” were artificial only insofar as we related them, by agreement or action, in a definite way. Only miracles were “absolutely artificial,” and they were impossible.
After this introduction Rappaport delivered the main blow. Let us suppose that biological evolution could take a double path: it could create separate organisms, and then, from them, intelligent beings; or it could create, on the other branch, biospheres that were “nonintelligent” but at the same time highly organized — and let us call these “forests of living flesh,” or vegetation of still another type, one that in the course of a very long development would master even nuclear energy. The vegetation’s evolution would master it, however, not in the way that we mastered bomb or reactor technology, but in the way that our bodies “mastered” metabolism. In this case the products of the metabolism would be phenomena of a radioactive type — and, at a later stage, even streams of neutrinos, which would be nothing but the “excretion” from such globes, of the organisms on them, excretion which we would receive precisely in the form of a “stellar code.” In this case we would have a completely natural process, because beings would not be intending to send anything to anyone, or to communicate, and the streams in question would be only the inevitable result of their metabolic activity, an “excretory emission.” But it could also be that other planetary organisms would learn of their presence by this “spoor” left in space. Then it would constitute a kind of signal between them.
Rappaport added that his hypothesis fit into the class of things native to science, because science did not divide phenomena into “artificial” and “natural,” and therefore he had entered into the spirit of its rules. The hypothesis, in principle at least, could be tested (by detecting the presence, or merely proving the theoretical possibility, of “neutrino organisms”), because it did not refer us to “other Universes.”
Not everyone grasped that this was more than just an exhibition of wit. It was possible, in principle, to predict and calculate any type of organic metabolism when one began with physics and chemistry, whereas it was not possible, beginning with the same physics and chemistry, to predict or calculate a culture in which certain beings would write and send “neutrino letters.” This second phenomenon was of another, nonphysical, order. If civilizations spoke to one another in different languages, and their differences in development were considerable, at best those who were less knowledgeable would extract from the received communication only (or nearly only) what was physical in it (or natural, the same thing). They would understand nothing more. And in fact, with a sufficiently large gap between civilizations, the same concept-symbols, even if they functioned in both cultures, would have totally different referents.
There was discussed, among other things, the question of whether or not the probable “civilization of the Senders,” either existing or (according to Sylvester) no longer among the living, was rational. And how could we say that a civilization that concerned itself about what would be “in the next Universe,” thirty billion years away, was rational? Even for a fantastically wealthy civilization, what had to be the cost, the price paid in the fates of living beings, for it to become the helmsman of the Great Cosmogony? This also, analogously, held for the “life-causing effect.” One might say that for them this was rational — or that there was no intercivilizationally constant sense of “rationality.” A dozen of us gathered at Baloyne’s after the closing of the meeting, and talked long into the night. If Sylvester and Lerner failed to convince us, they definitely poured oil on the troubled waters of the past. There was discussion about what Rappaport had presented. He added to it and made clarifications, and from this emerged a strange picture indeed — of leviathan biospheres that “sent” into the Universe, unaware of what they were doing; of an advanced stage of homeostasis, unknown to us; of amalgamations of vital processes which, drawing upon the sources of nuclear energy, began to equal, in their metabolic conversions, the power of suns. The biophilia of their “neutrino excretion” represented an effect exactly like that of the plants, whose activity had filled the atmosphere of Earth with oxygen, thus making life possible for other organisms, organisms that did not know of photosynthesis. And surely it was unintentional on the part of the grass to give us the opportunity to exist! Frog Eggs and the whole “informational” side of the letter became the products of an incredibly complex metabolism. Frog Eggs was a kind of waste, a cinder whose structure derived from planetary metabolisms.
When Donald and I returned to the hotel, he said at one point that he felt basically cheated: the leash on which we ran in circles had been lengthened, but that changed nothing in our situation of confinement. We were spectators at a nice display of intellectual fireworks, but when the show was over, we were left empty-handed. Perhaps — he went on — something had even been taken away from us. Before, the consensus omnium had stood behind the concept of a “letter” in whose envelope was found a little sand (meaning Frog Eggs). As long as we believed that we had received a letter, however incomprehensible it was, however mysterious, the knowledge of the existence of a Sender had value in itself. But now, when it turned out that perhaps the thing was not a letter but a meaningless scrawl, nothing remained to us except the sand. . . and even if the sand was gold dust, we felt reduced to poverty — more, we felt robbed.
I thought this over when I was alone. I tried to figure out where the certainty in me came from which allowed me to dispose of other views, no matter how well buttressed by arguments they were. I was convinced that we had received a letter. It is very important to me to convey to the reader not just this belief of mine — the belief does not matter so much — but the reasoning behind it. If I fail here, I should not have written this book. For that was its goal. A man who, like myself, has grappled long and often, on many changing fronts of science, with the problems of solving “Nature’s ciphers,” truly knows more about them than you will find in his mathematically tidy publications.
On the authority of this unconveyable knowledge, I maintain that Frog Eggs, with its reservoir of nuclear energy, with its “tele-explosion” effect, should have been turned into a weapon under our hands, because we strove so very hard, and desperately, to do this. That we were unsuccessful can be no accident. We had succeeded — in other situations, which were “natural” — all too often. I have no difficulty imagining the beings who sent the signal. They said to themselves: We will make it undecipherable for all who are not yet ready; but we must go further in our caution — so that even a false reading will not be able to supply them with any of the things that they seek but that should be denied them.
Not atoms, not galaxies, and neither planets nor our own bodies has Anyone cordoned off with such a system of safeguards, and we bear all the dismal consequences of that Neglect. Science is the part of culture that rubs against the world. We scrabble out pieces from the world and consume them — not in the order that would be best for us, because No One was so kind as to arrange this, but in an order that is regulated only by the resistance that matter itself presents. The atoms and stars have no reasons; they cannot defy us when we fashion models in their image; they will not bar our way to knowledge that may possibly be lethal. Whatever exists outside man is like a corpse: it can possess no intention. But the moment the forces not of Nature but of Reason direct a message at us, the situation changes completely. The One who sent out the letter was motivated by a purpose that was definitely not indifferent to life.