Reading Notes for Class 2: Ancient & Medieval Ideas

The readings will give you an overview of the general state of ancient and medieval thinking about the earth. As you will see, the perspective on nature is quite different from ours but it is important to understand the framework that structured the early development of “geological” thought. This will help you understand the early debates and questions objects such as fossils, minerals and strata.

Harris notes 

Section 2 will provide you the general background to these topics, including basic information on ancient authors, their observations, and how these were transferred to Medieval and Renaissance Europe.

Harris (2018) The Influence of Plato and Aristotle…

This summary will introduce you to the (somewhat strange) ancient Greek perspective of the natural world. As noted in this text, it is difficult to find good introductions so I wrote this in response to past classes’ request. The importance is that this was the starting point for later natural history – as you will see in the following readings.

Adams (1938), Generation of Stones, p. 77-94 

Adams’ book is rather old but is really useful on some topics. This selection is a discussion of the three main Medieval-Renaissance theories on the “generation of stones”: an Aristotelian theory, the Petrific Seed, and Lapidifying Juice (great names!). You will see that he tends to drop in quotes from Latin and French (sigh) but these can be jumped over. Please read the introductory section and the section assigned to your group in class; skim the rest.

  • The Aristotelian theory has a useful summary of “properties”, “elements” and “exhalations” that follow from the prior reading. Adams also includes some information on how this was developed in later Medieval and early Renaissance times (p. 82-84) – there was some consideration about the role of “congelation”. As I noted before, he seems to overdo the “celestial influences” but this may reflect Platonic ideas about celestial correspondences (see the Rudwick reading).
  • The second theory of the Petrific Seed removes the “celestial influences” and shifts to consideration of Aristotelian “anima” (p. 85) and how to stones in the earth. I find the summary of de Clave’s version (p. 87) to be the most coherent of the three versions presented here.
  • Finally, the Lapifying Juice! The second paragraph outlines the basic idea. Note also the differentiation of different kinds of “succus” related to process of formation (p. 91-92). What strikes me is that this shifted into thinking about processes about how different kinds of stones formed – this is particularly notable in the work of Agricola (p. 93-94).

Rudwick (1976) Fossil Objects: p. 18-35

Rudwick’s book is subtitled “Episodes in the History of Paleontology” – this selection is from a chapter that looks at natural history in the sixteenth century that uses Conrad Gesner as its central figure. (And just to clarify the dates of the two Gesner books mentioned: “History of Animals” was published in four volumes in 1551-58; “On fossil Objects” was 1565.) This extract considers the continuing impact of Aristotelian and Neo-Platonic ideas on how naturalists interpreted “fossils” (here in its original meaning anything dug up from the earth), particularly those termed “figured stones” based upon them having some geometric shape(s). In general, this selection deals more with the form of objects, whereas the Adams selection focused more on their composition.

  • Section VI discusses (Hermetic) Neoplatonic ideas of the microcosm-macrocosm and hidden correspondences. These are Neoplatonic because they did not originate with Plato but were developed from his ideas in the early centuries AD. These are rather odd ideas as viewed from today but consider how they may emphasize geometric shapes and comparisons between stones, plants and animals as well as between the heavens and terrestrial realms.
  • Section VII turns to more Aristotelian ideas through the question of how to classify natural objects. Agricola’s basic groups (p. 23) persisted in some form for almost two centuries! Here you can see how Neoplatonic and Aristotelian ideas provided frameworks that could explain stones.
  • Section VIII arrives at a critical question: Why was the interpretation of figured stones so difficult? There were real obstacles due to the nature of the material and inadequate knowledge of modern forms; these overlay the conceptual problems noted in sections VI and VII.
  • Section IX addresses an even more critical point for us: how both Neoplatonic and Aristotelian theories provided coherent interpretative frameworks for how figured stones could be generated that did not require a simple organic origin. Here Rudwick draws upon the ideas of the “anima” and “petrific seed” (see Adams reading) to lay out how these older ideas framed thought well into the sixteenth century.

These readings cover a vast amount of time from Ancient Greece to the sixteenth century. In class, our focus will be on ancient natural history (mainly Aristotle), its influence on later European thought, and the struggles to begin to understand the origins and forms of stones and fossils. You will spend some time summarizing the important points of these readings. The work will be done in small groups, so come prepared to contribute. Here are some basic questions to consider before class.

  • How did their physical environment influence ancient authors interests and observations of the natural world? Within this framework, what kind of entities and processes were present in the physical world?
  • Aristotle’s works presented the most comprehensive framework for natural history emerging from the natural world. Within that framework:
    • How was the universe organized?
    • How did the four properties/four elements model explain nature (or at least the terrestrial part of it)?
    • What caused change (natural phenomena) in the natural world?
  • How was the “generation of stones” explained in the three major theories? (Focus on your assigned theory.) What kind of evidence could be used to support each?
  • To what extent do these theories reflect a progressive move from Aristotelian model toward a more complicated idea?
  • How were “figured stones” and “fossils” conceptualized? Why was the boundary between organic and inorganic uncertain and porous?
  • More specifically, how did the Aristotelian and Neoplatonic worldviews provide coherent interpretive frameworks for interpreting figured stones?
  • Finally, are you as amazed as I am over how long the ancient ideas permeated natural history?

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