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Stallo, Johann Bernhard


(b. Sierhausen, Oldenburg, Germany, 16 March 1823: d. Florence, Italy, 6 January 1900). philosophy of Science.

Stallo’s father was a teacher, as were his ancestors on both sides for many generations. After a private education, at the age of thirteen he entered the normal school at Vechta and then the Gymnasium. In 1839, when he was ready to enroll at a university, lack of money led him to emigrate to the United States, where he joined the German colony in Cincinnati. At first Stallo taught mainly German in a Catholic parish school; at that time (1840) he published a textbook, ABC, Buchstabier und Lesebuch,für die deutschen schulen Amerikas which went through several editions and was widely used. While teaching at St. Xavier College from 1841 to 1844, he continued to study Greek and mathematics. From 1844 to 1848 he was a professor of physics, chemistry, and mathematics at St. John’s College (now Fordham University) New York City.

In 1847 Stallo returned to Cincinnati and began to study law, a program he pursued until 1849, when he was admitted to the bar. From 1852 to 1855 he was judge of common pleas, before returning to private practice. In 1870, before the superior court at Cincinnati, he defended the Cincinnati School Board against the Protestant who clergy tried to enforce the retention of Bible reading and hymn singing as a part of the curriculum. From 1884 to 1889 he was American ambassador in Florence, where he remained even after his official period of service had ended.

The development of Stallo’s thought can be characterized as a gradual transition from postKantian idealism in his youth to his own version of positivistically oriented phenomenalism in his mature years. He studied Leibniz, Kant, Herbart, Schiller, and Goethe while still in Germany. This influence is visible in the poem “Gott in der Natur,”published in Wahrheitsfreund (Cincinnati, 1841) which enthusiastically proclaims, in Goethe’s fashion, the unity of God and nature. In 1848 he published The General Principles of the Philosophy of Nature, With an Outline of Its Recent Developments among the German; Embracing the Philosophical Systems of Schelling and Hegel and okens’s System of Nature, the title of which indicates Stallo’s exclusive commitment to Nature philosophie. The book is now of value only as a document illuminating the early stage of Stallo’s philosophical development, and Stallo himself later conceded its worthlessness: “That book was written while I was under the spell of Hegel’s ontological reveries—at a time when I was barely of age and still seriously affected with the metaphysical malady which seems to be one of the unavoidable disorders of intellectual infancy” (preface to The Concepts and Theories of Modern Physics [New York, 1881]). Realizing that these words may have been too harsh, he added: “The labor expended in writing it was not, perhaps, wholly wasted, and there are things in it of which I am not ashamed, even at this day. . .” (ibid).

It is not difficult now to see what those things were in Stallo’s first book that he was not ashamed of in his mature years. One idea was common to all phases of his thought: that things are not “insular existences” but complexes of relations. Also, the influence of the book was not as negligible as Stallo believed. There is definite evidence that his “evolutionary idealism” greatly appealed to Ralph Waldo Emerson, who copied passages from Stallo’s book into his journals beginning in November 1849: in 1873 he even credited Stallo with having anticipated Darwin’s theory of evolution by regarding animals as “foetal forms of man.” Even Later Thomas Sterry Hunt, the American chemist and geologist, conceded Stallo’s influence and dedicated A New basis for Chemistry (Boston, 1887) to him.

In 1855 Stallo wrote a critical essay on materialism, published at Cincinnati in Atlantis (pp. 369–386) and then as a separate offprint entitled Naturphilosophische Untersuchungen. Der Materialismus. It represents an intermediate stage between Stallo’s early Hegelianism and his mature work in the philosophy and epistemology of science. Its main target was materialism, which had been revived in Germany and was becoming popular in the United States, especially among German immigrants. Stallo explicitly mentioned Karl Vogt and Ludwig Feuerbach. His criticism was written in a semipopular style and clearly was directed to a wide audience. It consists of three distinct parts: an analysis of the epistemological assumptions of materialism; a questioning of its scientific adequacy; and a sharp rejection of the materialistic reduction of thoughts to the brain processes.

In the first part Stallo showed the intrinsic inconsistency of the materialistic epistemology that claimed that all knowledge comes from sensory perception and at the same time postulated the existence of atoms that can never be perceived; furthermore, in basing all knowledge on the sensations—that is, on conscious data — it unwittingly conceded their primary character (contrary to its professed reductionism). In the third part Stallo criticized the then famous statement of Karl Vogt, “The brain secretes thought as the kidney does urine. . .” He concluded by recommending that materialists read Kant’s Critique of Pure Reason and Hegel’s Phenomenology of Mind.

Stallo’s original idealism is even more apparent in the middle part. His main argument is the alleged inadequacy of the atomistic explanation of chemical phenomena. At that time the distinction between the atom and the molecule was still not clarified, and thus Stallo’s doubts about the indivisibility of the atoms appeared plausible. Similarly. chemical formulas were still far from being established (there was, for instance, still a dispute over whether the formula of water was HO or H2O) and structural formulas were unknown; thus it was easy for him to speak of “the chaos in organic chemistry.” Stallo obviously mistook the temporary incompleteness of the atomic theory for its basic inadequacy. That he was still far short of positivism is indicated by the polemical note against Comte’s veto of any metaphysics. On the other hand, it contains the idea found in his first book: that every material thing is a network of forces and relations (das Gewebe von Kraften und Beziehungen).

The preface to Stallo’s Concepts and Theories of Modern Physics is dated 1 September 1881. Three years later, in the extensive introduction to the second edition, he stressed that the main purpose of the book was an epistemological criticism of the corpuscular-kinetic theory of nature. In the first eight chapters he restated the basic theses of the “atomo-mechanical theory” (as he called it) and showed its empirical difficulties. These basic theses were the following: (a) The primary elements of all natural phenomena are mass and motion. (b) Mass and motion are disparate.“Mass is indifferent to motion, which may be imparted to it, and of which it may be divested, by a transference of motion from one mass to another. Mass remains the same, whether at rest or in motion.” (c) Both mass and motion are independently conserved. From these theses two general corollaries followed: (a) All phenomenal diversity is reducible to quantitative differences in configuration and motion. (b) All apparently qualitative changes are reducible to the quantitative changes of position and configuration. These two corollaries thus imply the absolute homogeneity, hardness, rigidity, and passivity of the basic elements of matter.

In subsequent chapters Stallo showed how all previous propositions followed from the basic principles of the “atomo-mechanical theory” and how they simultaneously contradicted the empirical findings of his own time. Thus the claim that the basic units of matter are homogeneous followed from the qualitative unity of matter assumed by classical atomism, but it was at variance with the irreducible diversity between the atoms of different elements. Stallo believed that the persistent hope of reducing these differences to different configurations of the more basic and truly homogeneous units had been definitively buried by the failure of Prout’s hypothesis, Similarly, the classical assumption of absolute hardness and rigidity of the basic material units was contradicted in the area where the triumph of mechanistic explanations seemed to be the most spectacular —in the kinetic theory of gases, based on the very opposite assumption of the elasticity of the bouncing particles. Yet the concept of an elastic (compressible) atom was a contradiction. The passivity of the basic material units implied the denial of action at a distance, and Stallo again emphasized how persistent the tendency is to reduce all dynamic interaction to the direct pressure and impact of bodies. This led him to point out the difficulties of the kinetic explanations of gravitation, of the mechanical models of ether, and of the theory of atoms as “vortex rings” proposed by William Thomson (later Lord Kelvin).

After showing what he regarded as the empirical inadequacies of the corpuscular-kinetic models, Stallo proceeded to trace their shortcomings to “the structural fallacies of the intellect,” which he attributed to the following four assumptions: (a) that to every concept there corresponds a distinct objective entity; (b) that the alleged entities corresponding to more general concepts exist prior to the entities corresponding to less general concept; (c) that the order of the genesis of concepts is identical with the order of the genesis of things; (d) that things exist independently of and antecedently to their relations. Thus had arisen “the four radical errors of metaphysics,” characterizing “the atomomechanical theory,” The concept of homogeneous matter, devoid of concrete sensory qualities and existing separately from motion and force, was merely a reified abstraction, comparable with the Hegelian “Being,” even though Stallo conceded that it was “somehow less hollow.” With equal severity he censured Bošković and the dynamists for their reification of the concept of force. The assumption of the absolute solidity of the basic material units was a mere prejudice due to man’s psychobiological conditioning: the fact that “the most obtrusive form of matter is the solid,” which was first recognized and manipulated by “the infant intellect of mankind,” was the basis of man’s tendency to interpret every physical phenomenon in corpuscular terms and every physical interaction by direct contacts and impacts of such solid particles. But there was no absolutely solid body, nor was there any absolutely gapless contact between bodies in nature.

The most valuable and most prophetic insights are expounded in this part of the book. Stallo’s firm opposition to the fiction of “insular existence,” originally motivated by the metaphysical idea “the relatedness of reality,” was placed on a more convincing basis of concrete physical considerations. He pointed out that the concept of the isolated material body, whether on the atomic or the macrophysical scale, as well as the concept of the single isolated force, was physically meaningless. All physical properties were relational and owed their existence to the physical interaction between various parts of the world. Even inertia, which, according to Newton, represented the very core of matter (vis insita) was no exception. Stallo demonstrated it in analyzing Carl Neumann’s argument (1870) in favor of the Newtonian absolute space. His thesis was a modification of Newton’s classical argument: the absolute rotations (the rotations with respect to absolute space) are physically distinguishable from mere relative rotations, since in the first case centrifugal forces arise while in the second case they do not.

Neumann inferred from this that centrifugal force would appear on an absolutely rotating body even if it were completely alone in space. Against this Stallo claimed that not only the rotation of a solitary body, but even its very existence, would be utterly meaningless if no other bodies existed: “All properties of a body which constitute the elements of its distinguishable presence in space are in their nature relations and imply terms beyond the body itself”’(Concepts and Theories. p. 215). He clearly anticipated a similar criticism of Newton by Ernst Mach, who concluded that in the principle of inertia there is “an abbreviated reference to the entire universe”and that“the neglecting of the rest of the world is impossible.” This passage from Stallo’s book had appeared in Popular Science Monthly in 1874 and shows that Mach’s criticism of Newton was anticipated a full decade before Mechanik in ihrer Entwickelung appeared. Stallo arrived at the same conclusion in showing that Newton’s third law requires the existence of at least two bodies in the universe. He quoted Maxwell’s comment on this law: Action and reaction are two complementary aspects of the same phenomenon —stress; thus the concept of a single, isolated force is as meaningless as that of a solitary body. Such a body would be not only without weight but also without inertia.

The second anticipatory insight in Stallo’s book was his epistemological criticism of mechanical models in general. Its basic idea was concisely expressed in his statement that “a phenomenon is not explained by being dwarfed.” In other words. to explain the properties of macroscopic matter by postulating the very same properties on the microphysical scale was no explanation at all. Stallo thus raised doubt about the adequacy of the mechanical and. more generally, intuitive models of the microcosmos. It is hardly necessary to stress how prophetic his view proved to be and how bold it was in the era when William Thomson equated the understanding of any physical phenomenon with the possibility of making a mechanical model of it.

On the other hand, Stallo dogmatically excluded non-Euclidean geometries from physics. His position in this respect was not consistent; and his arguments against “transcendental geometries,”as he called them, were inconclusive. First, he claimed that the curvature of space implies the absolute finitude of the material universe, which is “a necessary complement of the assumption of its absolute minimum, the atom.” This clearly is not true of Lobachevsky’s space, which is infinite. Second, he claimed, as Poincaré did later, that no empirical proof can ever be given for a non-Euclidean character of space; even the discovery of a nonzero parallax of very distant stars would not be conclusive, since it would be more natural to explain it by some deviation of the light rays in space rather than by some intrinsic curvature of space. He dogmatically insisted that by its own nature space must be homogeneous, confusing homogeneity with Euclidean character; he did not realize that Riemannian and Lobachevskian spaces of a constant curvature are also homogeneous. Finally, he claimed that the concept of a straight line, purportedly eliminated by Riemann and others, was surreptitiously reintroduced in the form of “the radius of curvature.” Stallo clearly misunderstood the metaphorical nature of this term, which can be taken literally only for two-dimensional illustrative models of non-Euclidean spaces and not for those spaces themselves, for which the term “space constant”is less misleading than “radius of curvature.”Thus today we see that it was Helmholtz and Clifford who were on strong ground, rather than Stallo, who criticized them.

In Essay on the Foundations of Geometry (1897) Bertrand Russell pointed out the irrelevance of Stallo’s criticism of non-Euclidean geometry (p. 88), and his demonstration caught Ernst Mach’s attention. While disagreeing with Stallo about non-Euclidean geometry, Mach welcomed his criticism of what he called “mechanistic mythology” and referred to him in the fourth edition of his Science of Mechanics. He regretted not having known Stallo’s work earlier, and began a correspondence with him. Mach wrote the preface to H. Kleinpeter’s German translation of Stallo’s Concepts and Theories of Modern Physics (Leipzig, 1901), and dedicated his Principien der Wärmelehre (1896) to him.

This was not the only recognition that Stallo received, although his influence was greater on philosophers, particularly philosophers of science, than on scientists. Josiah Royce, in his introduction to G. B. Halsted’s translation of Poincaré’s Foundation of Space. recalled how scientific orthodoxy was shocked by the appearance of Stallo’s book. Its early translation into French (1884) also attracted considerable attention: it probably inspired Arthur Hannequin’s Essai critique sur l’hypothèse des atomes (1895); and Bergson, Meyerson, and L. Brunschvicg referred to it in their books. With the mourning crisis of the mechanical models in physics, Stallo’s work began to receive increasing attention: Rudolf Carnap referred to him in Der Raum (1922) and Physikalische Begriffsbildung (1926), and P. W. Bridgman reedited Concepts and Theories with his own introduction (1960).

In a broader historical perspective Stallo appears as one of the prophets of twentieth-century physics. Like Mach, he correctly recognized the inadequacy of the classical corpuscular-kinetic models on the microphysical scale and questioned the absolutistic assumptions of Newton. But, also like Mach, he failed to appreciate the fruitfulness of the same models on the macrophysical and molecular level. This failure was revealed in Stallo’s rejection of the kinetic theory of gases; his comments on this theory, especially his claim that it is simpler to assume “gaseousness” as a primary attribute of matter, are mere historical curiosities today. On the other hand, his lucid analysis of the logical structure of classical atomism is on a par with similar analyses by Kurd Lasswitz and émile Meyerson. and will remain a lasting contribution to the history of ideas.


On Stallo and his work, see M. ČPEK. “Two Critics of Newton Prior to Mach: Boscovich and Stallo,” in Actes du XII Congrès international sciences (Paris. 1968). IV. 35–37; Stillman Drake, “J. B. Stallo and the Critique of Classical Physies,” in Men and Moments in the History of Science (Seattle, 1959): Lloy D. Eaton, Hegel’’s first American Followers (Athens, Ohio, 1966); H. Kleinpeter, “Stallo als Erkenntniskritiker.” in Vierteljahrsschrift-ür wissenschaftliche Philosophie, 25 (1901), 401–440;and Die Erkenntnistheore der Naturforschung der Gegenwart. Unter Zugrundelegung der Anschauungen von Much. Stallo, Clifford, Kirchhoff, Hertz, Pearson und Ostwald (Leipzig, 1905);.J. H. Rattermann,.Johann Bernard Stalto, deutsch-amerikanischer Phhilosoph, Jurist and Staatsmann:.. (Cincinnati, 1902); and Lancelot Whyte,“Stallo Versus Matter,”in Anglo-German Review, 1 (1961).

M. Čapek

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