Biomimetic Chemistry and Synthetic Biology 39 4.1 Commercial and philosophical ambitions This is the grandiose program publicized by John Craig Venter, … 32 Bernadette Bensaude-Vincent There is a long tradition of boundary crossing in the history of chemistry. Medieval alchemists were condemned by the reigning scholastic culture because they subverted the order of nature in their attempts at making artificial gold and in a few cases to make life in a test-tube. Their nineteenth-century heirs, …

2. A Common Ancestor ‘Synthetic biology’ is a phrase coined in the early twentieth century by Stéphane-Armand Nicolas Leduc, a French medical doctor who developed a biophysical theory of life along with biophysical therapies. As he became an expert in the art of growing a variety of life-like shapes – such as trees, mushrooms or shells – out of solutions of carbonates, phosphates, silicates, nitrates or chlorides, he ambitioned to expand the domain of physical chemistry, a new science studying electrolytic and colloid solutions and the kinetics of reactions. 2.1 Leduc’s ambitious program Leduc’s program of ‘synthetic biology’ was exposed in his book Théorie phys- ico-chimique de la vie et génération spontanée and further developed in La Biologie synthétique .3 It consisted in imitating the forms, colors, textures, and movements of living organisms by osmotic growths. It is of special interest for the purpose of this paper because it was both synthetic and biomimetic. “The task of synthetic biology, he wrote, is the recognition of those physico-
Biomimetic Chemistry and Synthetic Biology 33 chemical conditions which can produce forms and structures analogous to those of living beings” (Leduc 1910, p. xv). Leduc belonged to the anti-vitalist movement. His ambition was to account for the phenomena of life with the properties of colloid liquids: Not only a crude solution of mineral compounds generates buds, stems, roots, branches without the presence of organic ferment, but also these life-like forms are analogous to living organisms in their fine structures, as they present colonies of microscopic vesicles separated by osmotic membranes. Le- duc went on claiming that they also display analogous functions, such as rhythmic and periodic movements, nutrition,4 and even a selective choice among the substances available in the surrounding medium. Leduc was so fascinated by the analogies between the mineral shapes grown in his test- tubes and living organisms that he boldly concluded (Leduc 1910, p. 3): Since then, we are totally unable to define the exact boundary which separates life from the physical phenomena of nature, we may fairly conclude that no such separation exists. All living organisms are transformers of energy, chemical transformers of matter and transformers of forms. Life originated in liquids and spontaneous generation is the corollary of the theory of evolution. 2.2. Naïve reductionism? At first glance, Leduc’s conclusions inspired by a crude and naïve reductionism seem almost absurd. Analogy is not identity. Consequently Leduc’s inference from the spectacular forms grown in inorganic solutions to the existence of spontaneous generation is clearly invalid. Leduc’s synthetic biology thus can be considered as a vestige of a time when chemists were confident enough in the power of their discipline to believe that they could provide explanations for the origin of life. However this prima facie judgment rests on a superficial understanding of Leduc’s program. Indeed Leduc was not naïve enough to mistake his life-like shapes for genuine living organisms. He presumably knew that mimicry is not a process of identification and that imitation presupposes the difference between the model and the copy. His claim is better understood as the expression of ‘methodological reductionism’. The synthesis of life-like structures by osmotic diffusion provided him with a model for investigating the forces at work in morphogenesis. Just as contemporary biologists use drosophila or mice as animal models for exploring the mechanisms of human diseases, Leduc used osmotic growths as a concrete model, an analogon for exploring the power of physical and chemical forces. He used his osmotic growths to identify the most basic conditions of life that he identified as “the ….

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