|
13th
DHS-DLMPS Joint Conference at Scientific Models : Their Historical and Philosophical Relevance |
Biological Models in Renaissance Chemistry
The Case of the Concept of Seed*
Hiro HIRAI
Centre
d'histoire des sciences, Université
de Liège, 4000 Liège
It is well-known to historians of
science that biological models were frequently applied to explanations of the
physical and chemical behaviours of natural
substances in early chemistry. Vegetable models of growth or maturation were
the favourite of the medieval
Latin alchemists. And late sixteenth-century mineral science in particular saw
the diffusion of ideas of this kind. Among these, the Renaissance concept of "seed"
seems to me the most striking one.
The concept of seed, established
under the authority of Plato during the late Renaissance by Neoplatonic
thinkers, is the missing link that unites the medieval theory of the "substantial
form" of the Scholastics and the theory of the "molecules" of
the mechanistic philosophers of the seventeenth century. It was designed to
explain the origin of the specificity and the organisation
of individual natural things, living and non-living, and their physical and
chemical behaviours. The invisible spiritual "seeds"
are considered as the vehicles of the form, or quiddity,
of each natural being, including the new diseases unknown to the Ancient
authors.
In the Renaissance period, Marsilio Ficino of the Platonic
Academy of Florence first formulated a metaphysical system incorporating the
idea of invisible spiritual seeds diffused throughout Nature. For this theory,
he combined the Stoic theory of logoi spermatikoi, transmitted by such Neoplatonic
thinkers as Plotinus and Proclus,
with Lucretius' atomistic idea of semina
rerum. For Ficino,
these seeds, which generate the forms of natural things in informed prime
matter, are sent from the heaven by the spiritus mundi, the uniting bond of the World-Soul and its
corporeal body (machina mundi).
Agrippa of Nettesheim is one of the earliest
followers of this Ficinian concept and the French
physician Jean Fernel introduced it into the learned medical milieu through his
very popular book On the Hidden Causes of Things (
Uniting this Paracelsian
idea with that transmitted by Jean Fernel, the Danish Paracelsian
Petrus Severinus
established a landmark in the history of the concept of seed by his book, Idea
medicinae (
Under the manifest influence of the
system of Severinus, the Flemish alchemist Van Helmont developed his ideas of "seminal principle"
and archeus faber, forged
on the model of Severinian "mechanical spirits".
The French atomist Pierre Gassendi, for his part, invented the term "molecule"
and identified his molecules with "seeds" of things. For Gassendi,
these seed-like molecules were directly created from atoms by God in the first
days of the creation and are endowed with their own scientia
for the further organisation of natural things. He
clearly acknowledges his indebtedness to the Danish Paracelsian
for this idea. Thus, these two giants of the scientific revolution, Van Helmont and Gassendi, shared a key source in constructing
their theories of matter, totally divergent to our modern eyes. This fact helps
us to understand why the most important seventeenth-century chemist, Robert
Boyle, had no difficulty in integrating the Helmontian
theory of "seminal principle" into his mechanical corpuscular
philosophy of matter, which he inherited much from Gassendi.
The trajectory of the Renaissance
concept of seed provides us a fascinating example of the application of
biological models to early modern matter theories.
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(*) This article is based on my doctoral dissertation : Le concept de semence dans les théories de la matière à la Renaissance de Marsile Ficin à Pierre Gassendi. (décembre 1999, Université de Lille 3, France). I would like to thank my friend Mr. Andrew Sparling for the correction of English of this abstranct although I am entirely responsable for the errors within.
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