Left: Friedrich Wohler's 1828 urea synthesis, which according to Henry Bray "bridged the gap" between organic and inorganic. Right: Mark Leach’s “organic vs inorganic” tree divide, representative of his “chemogenesis theory, according to which conceptualizes that chemical reactivity, organic, and inorganic “emerge” from the periodic table. (Ѻ)

“The idea of the unity of organic and inorganic nature is now firmly established. . . . All natural bodies which are known to us are equally animated, and the distinction which has been made between animals and inanimate bodies does not exist.”

“Some years ago chemistry was divided into inorganic and organic branches, on the supposition that what is known as the life-principle was somehow a necessary factor in the formation of the organic compounds; but since very many of these compounds have been made, and are now daily making, in all the laboratories of the world, this supposed principle of differentiation has to be given up. Today organic chemistry is sometimes called, ‘chemistry of the carbon compounds’; sometimes, ‘chemistry of the hydro-carbons and their derivatives’. By whatever name one may call it, chemists no longer believe that organic chemistry is dependent on any so-called life principle for the formation of its compounds. Especially is this true since potassium cyanide [KCN], urea [CH4N2O], potassium formate [HCO2K], and acetylene [C2H2] were formed by Wohler and Berthelot: and since in our own day carbon compounds exactly as they exist in the bodies of plants and animals are prepared hourly with simply chemical means. Thus therefore the supposed chasm between the so-called living and the so-called dead has been most certainly bridged [compare: unbridgeable gap].”

“What are the physical and chemical origins of diversity among inorganic and organic things, and how shall the adaptability of matter and energy be described? He may then see his way through all the difficulties which philosophical and biological thought have accumulated around a problem that in the final analysis belongs only to physical science, and at the end he will find a provisional answer to the question.”

— Lawrence Henderson (1917), Order of Nature [3]

“Even now there are serious conceptual discontinuities in the evolutionary theory, were its philosophical mission of unifying organic and inorganic nature is not fully realized. Whereas organic nature is pictured as purposive, self-serving, and, at least in its highest expressions, conscious, inorganic nature is conceived as behaving according to the blind mechanistic principles of chance and necessity.”

— Jeffrey Wicken (1981), “Chance, Necessity, and Purpose: Toward a Philosophy of Evolution” [4]

“Chemistry professors are unstable mixtures of predominantly unstable compounds which, in the exclusive presence of the sun's heat, decay irreversibly into simpler organic and inorganic compounds. That's a scientific fact. The question is: Then why does nature reverse this process? What on earth causes the inorganic compounds to go the other way? It isn't sun's energy. We just saw what the sun's energy did. It has to something else. What is it?”

— Robert Pirsig (1991), Lila: An Inquiry into Morals