Thales the Measurer

Livio Rossetti

• Publisher: Routledge
• Year: 2022
• Print ISBN: 9780367687090
• eBook ISBN: 9781000601862
• Edition: 1
• Topic: History
• Subtopic: Ancient History
• Index: History

Thales the Measurer offers a comprehensive and iconoclastic account of Thales of Miletus, considering the full extent of our evidence to build a new picture of his intellectual interests and activity.

Thales is most commonly associated with the claim that 'everything is water', but closer examination of the evidence that we have suggests that he could not have said anything of the sort. His real interests, and his real innovations, lay in challenges of quantitative measurement, especially measurements related to the movement of the sun. In this he had no predecessors – and, for centuries to follow, no real successors either.

This book is of interest for scholars in the history of philosophy, science, and life sciences. It is aimed especially at researchers in the field, but is also accessible to students and a more general readership.

Part I Approaching Thales

1 Who were these ancient masters?

DOI: 10.4324/9781003138723-2

1.1 A disconcerting oblivion

“Thales is all about water, Anaximander the apeiron and Anaximenes air; who doesn’t know that?” These associations are almost automatic, and this first impression is asserted in most current reference works as well as other, more specialised discussions. But it signals that any curiosity about the Milesians has been all but extinguished. A great fog, as it were, has descended upon their study.

But the fog sometimes clears, and one sees that, for example, one of these ancient masters, Anaximander, saw how a graphic representation of lands and seas might be produced by delineating the coastline. This amounts to imagining a view from above, rather than working with the perspective we would normally achieve with our eyes. This had not yet occurred to anyone, and Anaximander was the first to take concrete steps toward cartography and maps. Another Milesian sophos, Hecataeus, wrote a book entitled Periēgēsis (Περιηγήσις) οr Periodos gēs (Περίοδος γῆς, that is, Tour of the Earth), in which he gathered, for the first time ever, all the information then available concerning more than three hundred places (mostly towns) along the Mediterranean coast and in some inland areas (in particular, in the inland areas of Egypt and the Anatolian peninsula). It is easy to imagine how valuable this could have been, even if this information was only partially reliable. Thanks to the work of both of these thinkers, who were active some 2,500 years ago (before the Persian Wars, so before 490–480 BC), people began to have access to basic information about distant places and other peoples.

A third Milesian, the subject of this book, surveyed cosmic events, especially related to the sun; he saw how to date solstices and equinoxes, and understood why solar eclipses occur; he saw how it would be possible to use the shadows cast by the sun to measure the height of the pyramids; and he was able to measure the apparent amplitude of the solar disk.

Anaximenes, the fourth, had the daring notion that everything could be explained by air, a substance which could transform itself into other substances – water, in the first place – and which explains the origin of life.

This is already enough to show that associating Thales, Anaximander, and Anaximenes only with their reflection on water, apeiron, and air, respectively, is almost bizarre. Yet this is true even of the professional literature on these authors. A striking case is the book In the Light of Science. Our Ancient Quest for Knowledge and the Measure of Modern Physics (Amherst NY, 2014). The author of this book, the physicist Demetris Nicolaides, asserts that modern physics “is both an expansion and a reflection of various scientific ideas elaborated by prominent Presocratic philosophers”, and that “scientists of the twentieth century are still grappling with the fundamental problems they raised twenty-five centuries ago” (pp. 11–12). In Nicolaides’ eyes, Thales is precisely the water-theorist: this is inferred from the supposed fact that Thales merely taught that everything comes from water, a point Nicolaides exploits to claim that Thales established “the core concept of modern physics”, sameness, that is “the universal, underlying, simple principle that is a characteristic of all things in nature” (105).¹ But even passing over what we in fact know about Thales’ conception of water (see Chapter 9), and passing over the odd claim that these ancient intellectuals were the ones who identified the fundamental principles of modern science (which seems like an exaggeration), there is no doubt that this impoverished image of Thales (as well as Anaximander and other Presocratics), which became widespread in the twentieth century, dissolves upon closer inspection.

1.2 It is urgent to go beyond Aristotle

Most of the responsibility for the prevalence of this impoverished image of Thales and the others lies, unwittingly, with Aristotle. In a well-known text, the first book of his Metaphysics, he is thinking about the origins of the idea of an archē (a principle or primordial substance), and answers the question with this remark:

But Thales… says (phēsin) that that principle is water, and for this reason he also highlighted (apephaineto) that the earth floats on water. Perhaps he has derived this assumption from seeing that what nourishes all things is moist and that what is warm itself comes from this [i.e. water] and lives because of it (the principle of all things is that from which they come to be)—it is for this reason that he had this idea, and also from the fact that the seed of all things has a moist nature, and for things that are moist, water is the principle of their nature.²

The immediate problem here is that if Thales believed that the earth floats on water and that water nourishes all things (all seeds are moist, he adds), then it is very unlikely that he was talking about an originating principle, something to which for example even the stars can be traced. His conception of water rather seems to have been a resource internal to the world system in which we live – the water, namely, that manifests itself in rivers, springs, and wells. “That from which everything is generated” is not a cosmic element, but the humidity of the soil, as well as, perhaps, the liquid in the fertilized mammalian uterus or bird egg. However, what Aristoteles has in mind is the question of what everything derives from, and into which, at the end (teleutaion), it dissolves.³ So the question naturally arises: are Thales and Aristotle talking about the same thing? It seems doubtful. In Chapter 9, I shall show that Aristotle himself provides us with reasons to distrust what he says here. Nevertheless, in the meantime, almost everybody has followed Aristotle’s lead, and taught that the main doctrine and the core of Thales’ teaching consisted in identifying the archē as water – just as Anaximander later would have identified the archē with apeiron.⁴

It might help, in fact, to spend a little time with Anaximander. As I noted, he saw how one could represent the lands and seas on a map, and in fact attempted to draw a map of the entire Mediterranean area. This was the first such attempt in history, and was largely successful, despite the obvious challenges.⁵ But he did more than this too. He also defined a sort of primitive Astronomical Unit, equal to the diameter of the earth,⁶ and used it to estimate some cosmological distances – for example, the distance of the sun from the earth.⁷ And there was more. So why does this not feature more in current pictures of Anaximander – why does it not take up more space in discussion of him than his ruminations about the apeiron?⁸ Anaximander must have devoted more time to set up his map of the world and his work with (what I am calling) the Astronomical Unit than to refine his theory of the apeiron. And he must have been much prouder of making a map allowing everyone to ‘see’ not only Rhodes and Crete, but even Sicily, the Nile Delta, the Pillars of Hercules and the eastern edge of the Black Sea, and of his measurement of cosmic distances, than of having something to say about the apeiron.

I believe that the same is true of Thales. I cannot understand why less attention continues to be paid to his astonishing measurements than to his ruminations about water, not least because he was quite unique in his achievements in measurements. The fact that Aristotle’s own interest blinded him to Thales’ true creativity does not excuse us, who live in an age when quantitative data is so much more important.

These few considerations are enough to reach the conclusion that we will do well to extend our field of observation far beyond water and apeiron to which Aristotle (and, following him, Cicero) has directed attention.⁹ This is why I wanted to make a clean break with deeply rooted historiographical habits, and look for more solid foundations to reconstruct the significance of Thales. We have an abundance of information about him and, as we shall see, some is of real value. Little by little, I found myself in a condition similar to that of someone who owned a field traditionally sown with wheat and suddenly realized that there were splendid Roman mosaics just beneath the surface, and then began to uncover those mosaics. As a consequence, in the interpretation of Thales that I offer in this book, a number of texts which are usually overlooked receive much greater attention.

1.3 But we should go beyond Cherniss too

Cicero’s role in mediating evidence about the Presocratics to us (nn. 4 and 9, above) helps us to see that we need to achieve a critical distance from our sources; it is certainly useful to remember that each pursues its own ends and moves within its own context. However, it would be a mistake to assume that all we need to do is record where there is bias or oversimplification, in the manner of Harold Cherniss.¹⁰ Sometimes our sources themselves lacked relevant information or understanding (for example, concerning the difference between equinox and equilux: see Chapter 6). In the case of Aristotle, a lot can be explained by his own use (unknown to Cherniss) of work by Hippias of Elis. Hippias wrote a work, the Sunagōgē, which contained, as it has been possible to ascertain,¹¹ a sort of proto-history of Presocratic culture from Homer to Gorgias. This scheme was immediately adopted by Plato in the Cratylus, Isocrates in his Antidosis – and by Aristotle in the Metaphysics.¹² Hippias’ text has not come down to us, but these three texts do more than allow us to see that it existed.

In Cratylus 402a–c, the Platonic Socrates lingers on the theme of water and affirms that, for Heraclitus, everything flows, and it is not possible to step twice into the same river; that Homer had already spoken of Okeanos as father of the gods (Il. 14.201); that Hesiod had said something similar (Theogony 337 ff.); and that Orpheus himself (1B2 DK) sang that the first marriage was that of Okeanos to his half-sister Thetis. Similarly, Aristotle, when he is talking about Thales and water, writes that in remote antiquity, some “placed Ocean and Thetis at the origin of the generation of things”. We know, in fact, that Hippias wrote (I am summarizing here) that:

some of these things were said by Orpheus, others by Musaeus … others by Hesiod, others by Homer and others by other poets, then there are the sungraphai [works in prose] by both Greeks and Barbarians; I put together ta megista [the most important points] etc.

(86B6 DK = 36D22 LM)

Isocrates, for his part, spoke of the speeches of the sophistai, for one of whom the number of beings is unlimited, while for Empedocles there are four, for Ion three, for Alcmaeon two, for Parmenides and Melissus one, and for Gorgias none (Antidosis 269). For the link between Aristotle and Hippias, compare also what Diogenes Laertius says: “Aristotle and Hippias reported, on behalf of Thales, that…” (Lives 1.24).¹³

It is easy to see that Plato, Aristotle, and Isocrates were all using Hippias. Apparently, Hippias identified a common thread, a common interest in the origin of all things and found in water a connection between Thales and the poetic tradition. So, did Aristotle take Hippias on trust? Most likely yes, as we will see (in Chapter 9). It is his trust in Hippias that led him to think that water-as-origin was central to Thales’ teachings, and this, in turn, is what led Cicero, a large number of other ancient authors, and then innumerable historians of philosophy to suppose the same.

Hippias wrote the first literary chrono-topography,¹⁴ an attempt to bring order to the relatively recent past by tracing common threads uniting different characters. This sort of exercise always simplifies the data, often drastically. It seeks to tell us who stood before whom, after whom, higher than whom, and where; it helps its reader to remember the information by arranging it into a structure in which each character or event deemed significant is assigned a place. It is no wonder...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of figures
• Sources and Translations
• Foreword
• Part I Approaching Thales
• Part II Five quantitative inquiries
• Part III Three further investigations on earth, waters and rocks
• Part IV Other investigations: real and presumed
• Part V Final remarks
• Appendix to Chapter 7
• Bibliography
• Concordances
• Index Locoram
• Index