On Life and Evolution
Thales, Anaximander, and (as we will see in the next chapter) Anaximenes (collectively known as the Milesian philosophers since they were born in Miletus, a Greek city in Asia Minor) explained nature in terms of the variations of one universal substance. Nature, of course, includes us and all lifeforms. So an immediate consequence of their monistic theories is either (a) that there is no lifeless matter, but to the contrary, everything is somehow alive; each philosopher’s primary substance (the water, the apeiron, or, in Anaximenes’s case, the air) is somehow alive and so is everything that it transforms into. Or (b) that humans as well as all other species originated somehow from lifeless matter (the water, the apeiron, or the air).
View (a), which is known as hylozoism, was held by Thales and Anaximenes, and although highly controversial, it is still an interesting notion, for, despite 2,600 years of advancements in science and philosophy, a clear-cut distinction between animate and inanimate matter cannot be made. An unambiguous definition of what is alive or dead does not exist, as argued, for example, by four Nobel laureates: Charles Sherrington (1857–1952),8 Erwin Schrödinger (1887–1961),9 Werner Heisenberg,10 and Richard Feynman (1918–1988).11
View (b) has a certain similarity with the premise of the modern theory of biological evolution—that regards the various species to have evolved gradually from a common ancestor (or two, possibly more) speculated to have arisen spontaneously from lifeless matter. By spontaneously, I mean that the exact mechanism of life’s origin is not yet known, although chemical reactions are generally the assumed cause. Now, compared to the other Milesians, Anaximander had a more concrete and extraordinary theory of the origin and evolution of the species, including humans, that captures four specific aspects of the modern theory of biological evolution: (1) life arose spontaneously from lifeless matter, (2) more complex life did not arise spontaneously but evolved from the less complex, (3) life’s adaptation to its environment, and (4) survival of the fittest.12
Equally important, his theory was based on an accurately analyzed observation. Noticing that human babies are helpless at birth and for several years thereafter, Anaximander argued that humans could not have originated with the young of the species in their present form because they would have never survived. While newborns of other animals quickly support themselves, human babies cannot survive without long parental care. Therefore, he held that humans (and in general all animals) evolved from species, precisely fish, whose newborns were more self-reliant than human (or land-animal) babies.13
His general doctrine was that the most primitive forms of life were generated spontaneously in the moist element as it was evaporated by the sun—note that his notion of antithesis is present here, too, as the wetness of moisture versus the dryness of the sun. These living creatures had a protective spiny membrane and were the first kind of fish. With time, he speculated, they evolved to various other forms of fish. Then, some of their descendants abandoned the liquid element and moved to dry land, adapting to different conditions and evolving to new forms of life, including humans.14 Modern theories of biological evolution are quite similar: primitive microscopic life is speculated to have appeared spontaneously initially in water, evolved to fish, then to the sea-land transitional amphibia, to mammals, to primates, then to the first hominids from which modern humans ultimately evolved.
Newborn self-reliance was the first state in the development of life. Newborn helplessness and long parental care have developed afterward and most probably simultaneously: as a newborn need arose, an able parent addressed it. As if the evolution of a “bad” characteristic happens simultaneously with the evolution of a “good” characteristic, a notion, which if true, resonates well with Anaximander’s doctrine of the simultaneous appearance of opposites: an inefficiency in some area, say, the inability to walk at birth and for several months subsequently, may evolve simultaneously with a corresponding efficiency in some other area, for example, an advanced brain, so that one may moderate the other and keep things cosmically just—for example, the evolution of an empathetic brain allows parents to care for their helpless offspring for a long period. In general, the growing-up time increased with increasing brain size and complexity.
The selfless act of long parenting not only guaranteed the survival of the species but also, I believe, contributed to the overall bond between all people. Because once we began caring for our babies, we gradually began to care for our immediate and extended family, consequently increasing the chances to care more for our village, city, country, the human race, and ultimately life in general.
Conclusion
Anaximander’s intellectual leap is marked by three of his theories: in cosmology of an earth motionless in space without the need of a physical support, in biology on the origin and evolution of living creatures including the human species, and certainly of his theory on the primary substance of matter. With the latter, he modeled change and diversity in terms of constant transformations of the intangible, neutral, and conserved apeiron, into the concrete, competing, and transient opposites of everyday experience, and back and forth and with measure to preserve the cosmic justice. Nonetheless, it was Anaximenes who formulated the first graspable theory of change—of how matter can transform between its various phases: the gas, the liquid, and the solid.
* * *
1For a double etymology of apeiron, see Richard D. McKirahan, Philosophy before Socrates (Indianapolis: Hackett, 2010), 34 (Kindle ed.).
2Werner Heisenberg, Physics and Philosophy: The Revolution in Modern Science (New York: Harper Torchbooks, 1962), 36.
3Lederman and Teresi, God Particle, 56.
4In the Kelvin scale the absolute zero is 0 degrees Kelvin, which is –273.15 degrees Celsius, which is –459.67 degrees Fahrenheit.
5Aristotle, On the Heavens 295b10–16. Or see Daniel W. Graham, The Texts of Early Greek Philosophy: The Complete Fragments and Selected Testimonies of the Major Presocratics (Cambridge: Cambridge University Press, 2010), 59 (text 21).
6Karl R. Popper, Conjectures and Refutations: The Growth of Scientific Knowledge (London: Routledge, 1989), 138.
7John Burnet, Early Greek Philosophy (London: A & C Black, 1920), chap. 1.
8Charles Sherrington, Man on His Nature (Cambridge: Cambridge University Press, 2009), 302.
9Erwin Schrödinger, Nature and the Greeks and Science and Humanism (Cambridge: Cambridge University Press, 1996), 66.
10Heisenberg, Physics and Philosophy, 128.
11Richard P. Feynman, Six Easy Pieces (New York: Perseus Publishing, 1963), 22.
12Aëtius 5.19.4. Or see Graham, Texts of Early Greek Philosophy, 63 (text 37); Censorinus 4.7. Or see Graham, Texts of Early Greek Philosophy, 63 (text 38); Hippolytus, Refutation 1.6.6. Or see G. S. Kirk, J. E. Raven, and M. Schofield, The Presocratic Philosophers (Cambridge: Cambridge University Press, 1983), Kindle Location 3598; Plutarch, Symposium 730e. Or see Graham, Texts of Early Greek Philosophy, 63 (text 39); Ps.- Plutarch, Strom. 2. See Kirk, Presocratic Philosophers, Kindle Location 3590.
13Censorinus 4.7; Hippolytus, Refutation 1.6.6; Plutarch, Symposium 730e; Ps.- Plutarch, Strom. 2.
14Aëtius 5.19.4; Hippolytus, Refutation 1.6.6.
5
The Stepping-Stone to Truth
Introduction
In his search for the primary substance of matter, Anaximenes (who flourished ca. 545 bce) returned to the tangible world and chose air. His way of studying nature was economical and straightforward. Starting with a single material (air) of unchangeable nature, he managed to explain the manifold of natural phenomena quantitatively, in terms of condensation and rarefaction of matter. For with these opposite processes in mind, it was no longer necessary to ascribe all sorts of different properties to each object—such as rigidity, softness, hotness, coldness, wetness, dryness, fluidity, weight, color—just how dense it was. This idea in itself has a certain truth. But from a grander point of view as regards the evolution of science, his theory
was the stepping-stone to one of the most consequential truths of nature, the atom!
Condensation and Rarefaction
In Greek, “air” refers to any gas, and quite possibly in Anaximenes’s view, air was vapor water. His main question, however, was how a single material, air, in its gaseous state, could be transformed into all other forms of matter and account for the overabundance of dissimilar things, while itself remaining unchanged. What mechanism or processes could be applied to air, keep its substance unchanged, yet convert air into all the different things—solids, liquids, and gases? Change, he proposed, occurs via two opposite processes: condensation and rarefaction of matter.1 Successive condensations of gases transform them to increasingly denser matter, the liquids and solids, but successive rarefactions of solids transform them to increasingly rarefied matter and once more back to the liquids and gases, an essentially accurate idea. These processes cause changes in the density of matter but do not alter the very nature of matter (its very substance). Hence, every object is really air—in general, made of the same material—condensed or rarefied.
Why Air?
Air is in various ways of simpler form than other everyday substances. It is highly mobile and can be found almost everywhere. It is invisible, thus apparently unstructured and symmetric, and rarefied, thus quantitatively less. Symmetry, perceptible or subtle, was and still is a much-desired characteristic for nature in both ancient and modern scientific theories. In addition, starting from less (at least in a quantitative and visual sense, e.g., rarefied invisible air) and aiming to explain more2 (e.g., a denser, thus quantitatively more, visibly more structured, and thus in a way more complex substance), has always been the preferred approach in both science and mathematics; in mathematics, the fewer the assumptions (axioms), the more powerful a theorem is. Parenthetically, as regards religion, the reverse is true: polytheism preceded monotheism.
Now, although Anaximenes thought that fire is rarefied air and thus quantitatively less than air, still, as a primary substance fire seems to not have been adequate for him, for unlike air, fire is visible, has a variable form, and so is structured and asymmetric. Furthermore, air is needed for life through breathing, whereas fire destroys life. In fact air’s traditional association with soul (from the pre-Homeric times) might have influenced Anaximenes, for he writes: “Just as our soul, being air, holds us together, so do breath and air encompass the whole world.”3 The significance of fire in the explanation of natural phenomena will be elevated in the philosophy of Heraclitus (chapter 7).
Lastly, Anaximenes was an empiricist; thus, he abstracted his theory as a consequence of careful observations of various meteorological phenomena for which air had (or so he thought, anyway) a significant role. “When it [air] is dilated so as to be rarer [more rarefied], it becomes fire; while winds, on the other hand, are condensed air. Cloud is formed from air by felting [due to condensation]; and this, still further condensed, becomes water. Water, condensed still more, turns to earth; and when condensed as much as it can be, to stones.”4 He imagined objects to be in either one distinct phase (the solid, liquid, or gas) or in a mixture of phases; “Hail is produced when water freezes in falling; snow, when there is some air imprisoned in the water.”5
From Rarefaction and Condensation to the Atomic Theory of Matter
It will be argued that the discovery of the ancient atomic theory of Leucippus and Democritus—of atoms in the void—followed as a logical consequence of the ideas of rarefaction and condensation. And as we will see in chapter 15, modern atomic science has its roots in the atomic theory of antiquity.6
Softness and the Void, Rigidity and the Atoms
Softness occurs with rarefaction and rigidity with condensation, Anaximenes held, but how? Since everything is made of soft and penetrable air, why are some objects (e.g., the solids) rigid and impenetrable? Why is a piece of metal (which is supposed to be condensed air) incompressible and impenetrable, while air is compressible and penetrable? Why can we walk through air (so it seems, anyway) but not through a solid wall (which is supposed to also be air)? How do rarefaction and condensation really work, and how can we explain the varying degree of softness or rigidity in an object? Furthermore, what keeps matter together in a condensed or rarefied state?
First, let us take all four notions for granted—rarefaction, condensation, and the resulting softness and rigidity in an object. Then we ask: If we could imagine rarefaction and condensation to occur ad infinitum, what kind of an object would the absolutely most rarefied or condensed be? The most rarefied type of object would have zero density and would be absolutely soft, compressible, and penetrable; as if the object were void of matter; as if it were immaterial and did not exist; as if it were nothing! Now, an object void of matter is really a void, empty space. And so the most rarefied type of objects could be thought of as material-less gaps in space. On the other end of the limit, the most condensed type of objects would still be of the same substance, would have infinite density, would be absolutely rigid, incompressible, and impenetrable, and could be thought of as the matter that is filling up the nonempty space. These impenetrable pieces of matter that are also disconnected from each other by the void between them are precisely the atoms of Leucippus and Democritus, and the philosophically controversial void is precisely what they invented to facilitate the motion of their atoms and explain change.
“There are but atoms and the void,” said Democritus,7 or equivalently, “the full”8 and solid, and “the empty”9 and rarefied. First note that Anaximander’s opposites are present here, too, for the full and solid is the opposite of the empty and rarefied. Furthermore, “the full” seems to correspond to the aforesaid absolutely most condensed object, and “the empty” to the absolutely most rarefied object. Comparisons and details of the ancient and modern atomic theories will be carried out in chapter 12. For now it suffices to visualize tiny, indestructible (e.g., uncuttable) atoms, absolutely solid—and unable to rarefy—of all sorts of shapes moving randomly through the void, colliding with each other, either hooking with one another and clustering (condensation), or unhooking and dispersing (rarefaction). Thus, with atoms moving in the void, we understand how condensation and rarefaction are actually carried out—how matter can move, assemble, and stay together, or disassemble. And the consequent rigidity or softness is determined by the density of an object, that is, by how many atoms are cramped together within an object and by how much void is between them through which to move: the less the void, the more rigid the object; the more the void, the softer the object. Could the ancient atomic theory have been discovered through such type of analysis?
I don’t know if the atomists, Leucippus and Democritus, discovered atomism by analyzing rarefaction and condensation in the two extreme limits just described, but they were certainly capable of doing so, especially the great geometer Democritus. For such type of thinking, which in mathematics is part of what is known as the theory of limits, had already been invented and applied by him in other cases (e.g., in the calculation of the volume of a cone). In fact, Democritus’s knowledge on limits was commended by the great astronomer Carl Sagan (1934–1996) in this quote: “Perhaps if Democritus’ work had not been almost completely destroyed, there would have been calculus by the time of Christ.”10 By “work,” of course, Sagan meant, among other things, Democritus’s knowledge of limits, for to invent calculus a prerequisite knowledge is the theory of limits. Calculus was finally invented independently by Newton and Gottfried Leibniz (1646–1716) in the late seventeenth century.
One other way that the mathematical analysis of rarefaction and condensation might have aided the discovery of atomism is discussed next.
Continuous Versus Atomic
The challenge to understand how condensation and rarefaction themselves are carried out was important for the evolution of scientific ideas because it forced Anaximenes’s successors to think profoundly about the nature of matter. Consequently, they discovered two antithetical views: the con
tinuous and the atomic (the discontinuous). The complexities associated with the former guided the mathematical genius Democritus to atomism. Schrödinger argued that the mathematical challenges of the continuum were related to similar challenges of a continuously distributed model of matter.11 For example, we cannot tell how many points a purely mathematical line has. Analogously, if we have a material line (or in general an object), we cannot tell how many material points it has and how these points behave during rarefaction and condensation. Namely, how can an unchangeable substance of matter (e.g., Anaximenes’s air), distributed continuously within an object, rarefy or condense? “What should recede from what [so that an object can rarefy, or what should approach what so that an object can condense]? . . . if it is a material line and you begin to stretch it—would not its points recede from each other and leave gaps between them? For the stretching cannot produce new points and the same points cannot go to cover a greater interval.”12
In other words, can matter, modeled as continuously distributed in space, really move through other matter in order to condense or rarefy? Can new matter move into and occupy the space that is already occupied by other matter? When matter moves, where does it move into, and what does it leave behind? Why is matter able to move at all? How do condensation and rarefaction really work if matter is continuous? They do not! They work only if matter is discontinuous: made of disconnected, indivisible, and incompressible pieces—the atoms of Leucippus and Democritus—moving in the void. Rarefaction occurs when the atoms in an object recede in the empty space around them, and condensation occurs when they come closer to each other. “But by far the most important point about the rarefaction-condensation theory is that it was the stepping-stone to atomism which actually followed in its wake.”13
In Search of a Theory of Everything Page 5