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ANCIENT NATURAL-PHILOSOPHICAL IDEAS IN MODERN CHEMISTRY PAUL WALDEN Tiibingen-Gammertingen, Germany (Translated by Ralph E. Oesper)
GREEK PHILOSOPHY
Not more than a few hundred years (sixth t o fourth centuries B.c.) were needed by the ancient Greek genius to lay down reasonable philosophical bases of the origin, continuation, and understanding of the universe. The impulse came from the Greek colonies in Asia Minor and Lower Italy with their great business centers, and this development was favored by the economic prosperity of the colonies and the influx of foreign intellectual and cultural forces. I t was in this atmosphere that the untroubled minds of the Greek philosophers took up the contemplation and interpretation of Kature. Under the compulsion of mental economy, they proceeded from the simplest, the obvious, and what was closest at hand, and postulated that the All had originated in the One and that the whole world constituted an harmonious uuit ("Hen to pan"). From this starting point, Thales of Miletus (640-546) saw the origin of all things in water "which is in all and into which all returns." Heraclitus of Ephesus (cu. 536470) had a different explanation for all that is and happens: everything came from fire, it transforms substances, it is the soul of all things. He postulated a perpetual dynnmic of being in that he made a continuous state of flow (panta rhei)-a production and destruction-the basis of everything. This doctrine of continuous change was opposed by Melissos of Elea (sixth century B.c.) who set up the principle of eternal permanency or conservation since ". . .nothing can come from the non-being and hence that which has ever existed must continue in being forever aud ever." Parmenides (b. about 515 B.c.), head of the philosophical school a t Elea, brought this state of eternal being into sharper focus by emphasizing the eternity of the being comprehended through thought' as against the illusow sham produced by the senses. Previouslv, ~nax&enes (cd. 56040) had declared that air is the primal element. of all things, while Anaximander of Miletns (611-547) assumed a characteristicless ultimate material-the infinitefrom which all individual things are derived and into which they can all return. Anaxagoras (500427) a teacher in Athens, was the first to reject the one-element system. He not ouly promulgated a plural system of infinitely many elementary species (with unlimited divisibility of space and time), but he also was the founder of philosophical dualism, in that he postulated that matter embodies an ad-
' Comoare. e. "o... Plato's theow of ideas and Descartes (1611) "Cogito ergo sum."
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mixed spiritual principle (nus) which is responsible for life and movement. These theories were firmly united by Empedocles of Agrigentum (490-30) who assumed that the building blocks of matter are four in number: water, earth, fire, air. The multiplicity of materials results from the mixing (in definite proportions) or demixing of these elements, under the inhence of love and hate. Here is encountered, for the first time, a chemically oriented train of thought, which analytically foresees the composition and synthetically the cause of the union. About this time, Democritus of Abdera (cu. 460360), a pupil and fellow-citizen of Lencippus, set up a purely mechanical system through his theory of atoms. Real matter finds the limit of its divisibility in the ‘,atoms." These were assumed to be uncreatable, indestructible, and infinite in number and form (eudowed with points, hooks, loops, knobs, eto.) but of like substance; they had been in whirling motion since all eternity, and through collision, concatenation, coupling, and conglomeration they automatically unite to form the most varied material substances. "Sothing exists except atoms, motion and empty space. . . ." "Nothing is gotten out of nothing, and nothing passes away into nothing." Thus a physicalmechanical world picture appeared in the mental arena. Greek natural philosophy reached its zenith with Plato of Athens (427-344) and his pupil Aristotle the Stagirite (384-22). Plato accepted the four-element theory of Empedocles and-as did Aristotle laterrepresented the mutual transformations of the elements: Earth Ft Water
i;? Air
Fire
According to Aristotle, these four elements are the t". v ~ e for s the aired o ~ ~ o s i t of e sthe ~hvsicalaualities hot-cold, wet:dry. What is an element? " ~ e t us then define the element in bodies as that which is present in them, either potentially or actually, and which cannot itself be analyzed into constituents diiering in kind."2 Aristotle taught that one single kind of formless matter hule, (primal matter), is the basis of A
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%.IRISTOTLE,"On the heavens,'' Translated by W. K. C. GUTHRIE, Cambridge University Press, 1909, Chap. 3, p. 183. This olassic definition recurs: Avieenna (980-1037), Wilhelm de Conchis (twelfth century), Nicolaus Cusanus (fifteenth century; Daniel Sennert (IGlQ), Joachim Jungiup (1642). Rohert Boyle (1661), A. L. Lavoisier (1789), etc. The repetition of the ancient concept was important of course, but it lacked the emerirnental basis.-which guimnteed this limit of divisibility.
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all elements and things. "It is a basic principle of experience that everything in Nat,ure is in motion (change)," and God is the "unmoved mover," he is the "pure energy" (entelechy), "the pure soul of things," and teleology rules all events. THE DUALISTIC PRINCIPLE
According to the Eleatic school, the world is divided into the t,ao contraries: the morld of heing comprehended by the spirit (through thinking) and the urorld of appearances derived through the senses. The dualistic principle is organically anchored in the philosophy of Plato and his morld of ideas. The true and really existing world is that of ideas. This world picture was extended by Aristotle and given a fresh interpretation in an idealistic-metaphysical general world view. I n a world filled with ideas (as the active principle) all heing aud occurring is governed by a purposeful f o r c e t h e divine unmoved mover. I n direct contrast to this ideology, was the Democritean materialisticmechanistic world picture: in a world without b e ginning or end and without purpose, and consisting of void and atoms, eternally xvhirling in meaningless fashion, everything occurs automatically according to strict mechanical laws. The following fundamental dualistic ideas (or axioms) were set up with regard to matter and the changes it. undergoes: (1) Everything was created, aud by a higher power in purposeful fahion, and is subject to continuous transformation (the panta rha' of Heraclitus, the eternally unmoved mover of Aristotle); or everything is from all eteruity and aimlessly follo~vsits own causality aud autonomy (Democritus). (2) Everything has issued from a single prime element (Thales, Heraclitus, Democritus), all atoms consist of the same substance; or four elements (in fixed proportions) make up all bodies and worlds (Empedocles) and they in turn are derived from a single basic material hyle (Plato, Aristotle). (3) The various elemeuts are unchangeable (hnaxagoras, Empedocles); or the elements can he converted into each other (Plato, Aristotle). (4) The divisibility of matter has a limit, it is made up of indestructihle, eternal atoms as its smallest subdivisions (Democritus); or matter is a continuum and can he divided without limit (Plato, Aristotle). ( 5 ) A (biological) "creation and decay" governs the flow of heiug (Heraclitus); or alternatively a (mechanical) "mixing and demixing" is the basis of all change (Empedocles). (6) The interaction of materials and elements or atoms is the result of internal (psychic-metaphysical) causes, such as love aud hate (Empedocles), through nus or entelechy (Anaxagoras, Plato, Aristotle); or they react according to external purely mechanical principles, such as enchainment, adhesion, grappling (Democritus). (7) The dim paat obscures the origin of the axiom: "From what is not in being, there .can issue nothing,"
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or "Nothing decays into nothing," or "Whatever has been, has been forever, and always will be" (Melissos, Anaxagoras, Democritus, etc.). This axiom is the law of conservation for the totality of the real, the existing and the active, i. e., of the actuality; a priori it postulates the conservation and indestructibility of this reality of substance, force,3and spiritual powers, and guarantees the foundations of the perceptual activities with respect to natural phenomena. The contrast between the mental world of the Eleatics and the world of phenomena of Aristotle and Epicurns manifested itself in more recent times in the natural philosophy of Hegel and Schelling with their "speculative physics," which in short rejected the arguments of experimental chemistry as illusory. . . "all the more so because of the experiments." Dualism has always been important in the formation of chemical concepts. Opposites were: metals and nonmetals, noble and base metals; acids and alkalies; oxidation and reduction; inorganic and organic; heteropolar and homopolar, etc. This principle of dualism likewise prevails in physics, e. g., thrust-recoil; attraction-repulsion; action-reaction; or quite generally as the opposing action called forth by an active influence or the polarity of forces (such as electromagnetic), or force-matter; or ponderable and imponderable substances, et,c.; or mental recognition as against sense perception. Speculative physics explains that the ultimate "something" which fills the morld unites in itself the opposite of being and nonbeing. Animate nature uses this principle figuratively as a constant biological regulator that automatically intervenes as a constant. protect,ive factor. Modern physiology aud biochemistry are xvell acquainted with this "antagonistic principle" of the living organism, which of its own accord mobilizes antidotal materials to combat noxious materials that are upsetting the normal equilibrium conditions. For example, antitoxins oppose toxins, antiferments combat ferments; active materials (hormones, vitamins, etc.) undo the efferts of inhibitors; antibiotics consume harmful microorganisms, et,c. RECURRENCE OF FUNDAMENTAL IDEAS
The axiom of the conservation of all material suhst,ance (
