The primal air of prussic acid and carbonic acid in which humanity lived as soul and spirit before sun, moon and earth separated into three bodies.
The Prussic Acid Sun-Atmosphere in Anthroposophy is Rudolf Steiner's name for the air of the primal world body in which sun, moon and earth were still one, an atmosphere holding no oxygen and no free nitrogen but prussic acid (Blausäure, hydrogen cyanide) and carbonic acid. Steiner described it in the workmen's lecture of 10 October 1923 at Dornach, published in GA 351, How Spirit Works in Nature. In that condition the human being had no physical body: he lived as soul and spirit within the shared sun body, nourished by the cyanide air itself. When the sun departed it left nitrogen behind in our present atmosphere, and when the moon departed the carbonic acid released our oxygen. Today's air is therefore the residue of that separation. Origins-of-life chemists now treat hydrogen cyanide as the parent molecule of life's first building blocks, an unexpected echo of Steiner's picture.
The Prussic Acid Sun-Atmosphere names one of the strangest claims in Steiner's cosmology: before sun, moon and earth separated, the one world body breathed an air of prussic acid and carbonic acid, and humanity lived in it without a physical form. Our nitrogen and oxygen, on this account, are what the departing sun and moon left behind, a chemical memory of that first condition.
In Steiner's Own Words
You will say: But there was no real oxygen; in hydrocyanic acid and carbonic acid, man cannot live! Yes, gentlemen, as man is today, he could not live in that either; but in those days man did not yet have a physical body. He lived as a soul in this structure, in this heavenly body, which was the sun and earth and moon at the same time. And if we look at it properly, we simply come back to the fact that the whole nature of the heavenly bodies was different in those days, that when we still lived in the sun we naturally did not live on oxygen, but on prussic acid and carbonic acid. The sun, in which we lived, gave us prussic acid; the moon, which was inside the earth, gave us carbonic acid.
What it Means Today
Steiner told the Dornach workmen that life once fed on prussic acid, nine decades before laboratory chemistry began to say something structurally similar. In 2015 the chemist John Sutherland and his group at the MRC Laboratory of Molecular Biology in Cambridge published a study in Nature Chemistry (Patel and colleagues, "Common Origins of RNA, Protein and Lipid Precursors in a Cyanosulfidic Protometabolism") showing that hydrogen cyanide, the compound Steiner calls Blausäure, can act as the single parent molecule from which the precursors of RNA, proteins and lipids all derive. Sutherland's team had already shown in Nature in 2009 that activated nucleotides assemble under early-earth conditions from cyanide-derived feedstocks. Mainstream geochemistry likewise holds that the early atmosphere carried no free oxygen: breathable air is a late arrival, the product of a changed planetary condition. None of this confirms Steiner's clairvoyant cosmology, and Sutherland's cyanide is a building material, not a medium for souls. The difference deserves to be stated plainly. Thalira synthesis: where the Cambridge chemists find prussic acid at the beginning of life as its raw material, Steiner finds it at the beginning as the atmosphere of a humanity not yet born into bodies, so the two accounts agree on the substance and part ways on what was living in it.
Where to Read More