The philosophical basis of Central European pathology—background in humanities

Following the Baroque period, the medieval suppression and religious dominance were overcome. Starting with the thinking of the Enlightenment that flourished between 1740 and 1830, a new creative spirit went through science. In this period the reason itself was emphasized. This so-called age of rationalism triggered innovation and produced a scientific revolution. The novel perspective of interpreting nature by reason allowed a new view on natural phenomena. Such a newly developed kind of mental climate sowed ideas that led to a fundamental transformation of thinking. Keen thinkers such as Immanuel Kant (1724–1804; Fig. 1) provided the basis of future achievements. Kant stated, for example, that only reasoning allows the giving of order to knowledge—all knowledge has to be systematic. Systematic compilation is, therefore, a demand of reasoning in a dynamic and dual world of thinking and objectivity. This different approach shed new light on the functionality of organisms and especially on the relationship between health and malady. For the time being, one tried to explain illness by pure rationalizing. Friedrich von Schelling (1775–1854) interpreted life as a platonic idea of being, which led to the metaphysical idea of disease. Health and malady are related to each other quite similarly to how harmony and disharmony are related. The changed proportion between sensibility and irritability causes illness. In general, the period of German Idealism, with its key persons Kant, Hegel (1770–1831), and Schelling, influenced the creation of a philosophical medicine. Nevertheless, such speculative natural philosophy needed empirical preconditions. Both Schelling and Hegel engaged themselves in mathematics, physics, and botany—Hegel indeed visited an anatomy course [1]. Empiricism helped to recognize nature, but the exploration of knowledge—even Kant argued this way—should be handled by reason. It was Francis Bacon (1561–1626), the creator of empiricism, who established and popularized inductive methodologies for scientific inquiry. This method was picked up by Thomas Sydenham (1624–1689), who used systematic observation, comparison, and collection of observed material and implemented them into medicine. The speculative philosophy of identity by Schelling explained phenomena by inference of knowledge a priori. The British empiricist Bacon, however, stressed discovering our world by systematic observation. Instead of the scholastic concept of blind, directionless perception, such as trial and error, Bacon favored a well-planned observation called ratio inveniendi. He advised using technical devices such as the microscope to investigate blood, urine, and wounds [2]. These two movements of an ontological [3] and an empirical approach with regard to understanding diseases triggered several discussions. It is said that Schelling, and even more Lorenz Oken (1779–1859), left behind the ground of empiricism, which resulted in a fusion of romantic and metaphysical interpretation of nature. Natural philosophy by Oken was understood as counter pole to the traditional Galilean mechanistic principle [4]. On the other hand, Oken prefigured the fundamental concept of cell theory in his book Die Zeugung (OkenFootnote 1, Lorenz: Die Zeugung. Bamberg und Würzburg, Goebhardt, 1805). His prescient theory described all organisms as composed of so-called infusoria (i.e., single cells) that divide. Oken meant that organisms consist of those small vesicles (infusoria) which derive from a primordial soup. As the organism decays, these infusoria would be able to re-build a new organism. The romantic gynecologist Carl Gustav Carus emphasized in his talk at an opening ceremony that physics had to meet metaphysics—thinking about nature would comprise observation and speculation [5].

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Immanuel Kant (1724–1804). Painting by G. Döbler (displayed at Ostpreußisches Landesmuseum Lüneburg; Source: Wikimedia Public domain)

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At the time of the speculative and metaphysical interpretation of illness in Germany, the positivism of August Comte (1798–1857) sprouted in France. The dictum of Comte, “Order and Progress,” indicates his understanding that all science is hierarchically structured from the least to the most complex—from mathematics via biology to sociology. Comte’s positivism stands for the increasing mental tendency of categorizing knowledge in those days. Carl von Linné (1707–1778) was called the “Father of Taxonomy” because of his Systema Naturae that was published in 1735/1767. In this epochal book he systematically grouped all plants and animals according the morphological relationships among them. His trial to systematize human diseases failed. An analogous attempt was later undertaken by the Austrian-Bohemian pathologist Carl Rokitansky (1804–1878; Fig. 2) regarding diseases.

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Karl Rokitansky (1804–1878; Source: private collection R. Sedivy)

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Nevertheless, the answer to “What is disease?” definitely changed. The morbus diabolicus, where the Satan is the only cause of all illness, became disused. Natural philosophy used speculative and metaphysical explanations, but realized the importance of structured thinking that was needed to improve empirical knowledge. But another way of natural philosophy, originated by Karl Wilhelm Stark (1787–1845), substituted the old concept of satanic maladies by a parasitic idea of illness. This kind of notion interpreted illness as its own scrounging creature within the human body. Natural philosophy was at risk of being far too speculative, but a new awareness for critical thinking based on observation grew hereby. Another tribe of natural philosophy founded by Lucas Schönlein (1793–1864) focused on an empirical approach. Hence, this so-called romantic school of natural history did not understood physiology as a pure phenomenological interpretation as the thinkers of natural philosophy had done [6]. Schönlein’s ideas amended empiricism by classifying illness through a clinical nosological approach [7].

During the speculative-empirical period, pathology was more or less an applied pathological anatomy according to Morgagni’s concept of morphology. It started with Giovanni Battista Morgagni’s (1682–1771) idea of morphologically based diseases that progressively induced a comparison of post-mortem findings with clinical symptoms [8]. On the other hand, Schelling’s thinking found broad attention among romantic physicians. For such idealistic philosophers, life includes both health and illness as a whole. Thus, physiology and pathology were seen as one science [1]. Dietrich Georg Kieser (1779–1862), for example, believed that disease would be a self-dependent egoism of nature. In other words, the “bad” principle of life would disturb processes of life that are characterized by bipolarity. Life, in this way of understanding, might be oscillation between those two poles [2]. Post-mortem findings were, therefore, interpreted essentially following those concepts of romantic natural philosophy. Nevertheless, starting with the end of the 18th century, comparative anatomy was in focus. Taxonomy and observation as the basis of scientific interpretation gained more importance. This new scientific approach grew towards the Biedermeier period, where science could be roughly divided into the speculative-empirical stage and morphological experimental pathology [7].

One of the pioneers of that period was Karl Asmund Rudolphi (1771–1832), the teacher of Johannes Müller (1801–1858). Rudolphi was one of the key figures in the turn from romantic natural philosophy to modern medical science. Rudolphi was born in Stockholm as the son of German parents. He received his doctorate in 1795 at the Prussian University of Greifswald, where he was later appointed Professor of Anatomy by Napoleon I after the battle of Jena and Auerstedt (1806), while Greifswald was occupied by French troops. Wilhelm von Humboldt (1767–1835) recommended Rudolphi in 1809 as Professor of Anatomy and Physiology at the newly founded University of Berlin—a position he held until his death. He admired the work of Carl von Lineé and carried out studies of plant growth. He was an early follower of the view that the cell is the basic structural unit of plants. In 1804, Karl Asmund Rudolphi and Heinrich Friedrich Link were awarded the prize for “solving the problem of the nature of cells” by the Royal Society of Science of Göttingen, for proving true that cells had independent rather than common walls. Rudolphi died in Berlin in 1832, and was succeeded in his position at the University of Berlin by his prime student Johannes Müller (1801–1858).

The dawn of natural science

Johannes Müller, who was influenced by his teacher Karl Rudolphi, was one of the key figures within the sprouting physiology that put methods of natural science into practice. His school had an exceptional effect on all the fields of morphology [9]. But not only his personal work pushed forward this new way of research: also his disciples such as Virchow, Henle, Schwann, DuBois-Reymond, Brücke, Remak, Reichert, Kölliker, Helmholtz, and others were important. Together with the experimental approach, the evolution of the microscope and the use of advanced techniques helped the idea to prevail that only the combination of experiments and cognitive reflection would allow nature to be understand.

At first, Müller was quite a pupil of the contemporary romantic movement of science. But soon after he moved to the University of Berlin, where he came under the influence of the anatomist Karl Rudolphi, his thinking changed step by step. In 1826, he presented new material on human and animal vision in his book Zur vergleichenden Physiologie des Gesichtssinns (Comparative Physiology of the Visual Sense). He discovered that each of the sense organs responded to different kinds of stimuli in its own particular way. The phenomena of the external world were perceived, therefore, only by the changes they produce in sensory systems. Additionally, his findings had an impact even on the theory of knowledge [10].

Prompted by the discovery of one of his followers, Theodor Schwann (1810–1882), that tissues are composed of cells, Müller applied this finding to the micromorphology of tumors. Müller recognized that tumors also comprised sheets of cells and he identified therein nuclei, granules, fibers, and crystals. His book Ueber den feineren Bau und die Formen der krankhaften Geschwülste has become a milestone in tumor pathology and paved the way for Rudolf Virchow’s studies on cancer.

Another key figure was Carl Ludwig (1816–1895), who was the driving force in the foundation and development of scientifically based and experimentally oriented physiology, in contrast to natural philosophy and vitalism that prevailed during the first quarter of the 19th century in Germany. He was the representative of the so-called organic physicists, a small group of young physiologists who implemented the laws of physics and chemistry. Emil du Bois-Reymond (1818–1896), Ernst Brücke (1819–1892), and Hermann Helmholtz (1821–1894) were members of this group. Carl Ludwig went along with the ideas of this scientific group. It is known that Carl Ludwig and the contemporary organic physicists lived and grew in a science- and research-oriented period, which had been prepared and paved by men like Johannes Evangelista Purkyně (1787–1869), Ernst Heinrich Weber (1795–1878), and Johannes Müller (1801–1858). They all benefited from the enormous scientific development and even contributed to it to a large and significant extent. Ultimately, their work turned out to be most influential in the history of German physiology. Some of Carl Ludwig’s scholars, e.g., Adolf Fick (1829–1901), Otto Frank (1865–1944), and Iwan Petrowitsch Pawlow (1849–1936) carried his approach to physiology into the 20th century [11].

The birth of the cell

Until the 19th century, several scientists thought that diseases were analog to the principle of abiogenesis (i.e., life arising from nonliving matter, such as simple organic compounds), and thus maladies might originate from nonliving matter as a result of spontaneous generation. With regard to the macroscopic perspective of morphology, Morgagni opened up another dimensional view because he compared clinical symptoms with changes of the specific tissues. Morgagni focused on disease as morphological change within the organ as a whole, whereas François Xavier Bichat (1771–1802) extended this view by taking a closer look at the tissue than Morgagni had done. Bichat realized that parts of organs—membranes and tissues—might be affected by disease. Nevertheless, he did not use the particular instrument of the suborganic dimension: the microscope. Without the discovery of the microscope, the next fulminant step in the evolution of pathological anatomy would not have taken place. It was Robert Hooke (1635–1703) who gave a visible picture to the Greek atomistic theory by Democritus (460–370 BC)—without realizing that his observed cork cavities were the residual skeletons of the basic subunits we today call cells. Although Aristotle (384–322 BC) dismissed the idea of a non-continuous matter, the Monadology of Gottfried Wilhelm Leibniz (1646–1716) allowed acceptance that the universe would be atomistic. Aristotle’s thinking decisively prevailed over many other Greek movements such as the corpuscular hypothesis by Democritus. Leibniz’s monads—simply substances that are generated by “continual fulgurations of the Divinity” (epiphany)—were thought to be the indefinitely small elements of the world. Starting with the late 18th century, tremendous advances in basic sciences and a new awareness of standards extended the medical horizons. When early microscopists finally looked at tissues of living forms, their observations were compared with theological and philosophical ideas of how the world should be constructed. Intriguingly, even optical illusions were declared as fundamental subunits of animate matter [12]. On the other hand, as early as 1664, Robert Hooke noted conspicuous “pores” that he called “cells” in biological structures (deriving from the Latin word cella for a small room or cubicle). The term “cell” widely found acceptance, whereas it was used in the 17th and 18th century as a gross description for loose connective (areolar) tissue. Hence, the meaning of “cell” or “cellular tissue” was different to the “cellular theory” that we encounter in the 19th century. A change of the old cell concept was launched by Theodor Schwann (1810–1882). He was one of the first scientists to recognize that cells are not only structural units. One day at dinner, Schwann heard from Schleiden (1804–1881), who reported about plant cells, that the nucleus might play an important role in cell development. Afterwards, Schwann intensively compared plant and animal cells and amassed a lot of concrete data. He described, at the end, a theory on structure and development of cells in “animal economy.” Although we now know that most of the model was wrong, the fundamental insight was valid. Schwann had erected his theory on two basic concepts: first, a matrix or blastema exists; and second, that cellular granules develop out of this blastema. Whereas Schwann applied his blastema concept to normal tissues, the well-known Viennese pathologist, Carl Rokitansky (1804–1878), used it to explain diseases, especially “new growths” [13]. Under this term, he summarized inflammatory reactions as well as that which we today call neoplastic growth. The source of the blastema should be the blood. Both Schwann and Rokitansky tried to explain a process through discrete static forms obtained by microscopy. But, as we know today, a tissue section in the microscope does not really indicate a process. This misunderstanding was corrected by a pathologist from the next generation: Rudolf Karl Virchow (1821–1902; Fig. 3).

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Rudolf Virchow (1821–1902; Source: private collection R. Sedivy)

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The contributions of Rudolf Virchow

Looking back, Virchow was one of the greatest scientists and pathologists of the 19th century. His work and thinking changed medicine as much as Copernicus did physics. Virchow emphasized observation and experiments as the only valid basis of a pathological physiology. Moreover, he condemned pure speculations and hypotheses created without solid data. A hypothesis only obtained value for him as a transition serving as a “mother” of experiments. When available facts may leave inexplicable gaps in a line of thought, only new facts were able and correct to fill them.

Virchow’s concept of cellular pathology was initiated while he was at Würzburg. Until the latter part of the 18th century, diseases were supposed to be due to an imbalance of the four fluid humors of the body (blood, phlegm, yellow bile, and black bile). This was called “humoral pathology,” which dated back to the Greeks. In 1761, the great Italian pathologist, Giovanni Battista Morgagni, realized that the origin of diseases was based rather on morphological lesions in organs. Around 1800, the French anatomist Xavier Bichat demonstrated that the bodily organs were made up of 21 different kinds of tissues, and he conceived that in a diseased organ, only some tissues might be affected. In contrast to humoral pathology, Morgagni situated the pathology of the solid matter within the entrails and organs, whereas Bichat put it within the tissues, and Virchow saw the roots of pathogenesis within the cell [14]. Thus, the ens morbi, the essential nature of malady, changed from the macroscopic to the microscopic level that represents the cellular principle of modern thinking [15]. This evolution is a recognizable turn along the past centuries, whereas Satan or scrounging creatures were no longer necessary to understand how diseases develop. The rise of the cellular principle started in Würzburg, when Virchow began to realize that the upcoming cell theory, which postulated that every cell originated from a preexisting cell, could give a realistic insight into pathogenesis. In this respect, he was influenced by the work of, e.g., John Goodsir (1814–1864) of Edinburgh, who saw the cell as a center of nutrition, and by the investigations of Robert Remak (1815–1865), a German neuroanatomist and embryologist, who in 1852 was one of the first to point out that cell division accounted for the multiplication of cells to form tissues. By that year, Remak had concluded that new cells arose from existing cells in diseased as well as in healthy tissue. Remak’s writings, however, had little influence on pathologists and medical practitioners. Virchow expressed his ideas in a condensed manner by the well-known aphorism omnis cellula e cellula (every cell is derived from a [preexisting] cell), which he mentioned for the first time in 1855 in his famous article Cellular-Pathologie in the Archiv der pathologischen Anatomie. Heirs of Hippocrates [16] commented that Virchow’s theory that the seat of disease could be traced back to the cell prompted his well-known dictum that complemented Harvey’s omne vivum ex ovo (every living thing from an egg) and Pasteur’s omne vivum e vivo (every living thing from a living thing). At that time, the word “egg” represented the beginning and the end of life, and was then also understood by analogy for the description of the so-called germinal vesicle (Keimbläschen). Remarkably, Harvey’s aphorism was engraved on the grave of Jan Evangelista Purkyně (1787–1869), who first described the germinal vesicle. Although Virchow’s dictum is not completely original, he elevated cellular pathology to overwhelming importance. Particularly, François-Vincent Raspail (1794–1878) coined the phrase omnis cellula e cellula (every cell is derived from a [preexisting] cell) prior to Virchow. However, the term “cellular pathology” belongs to Virchow alone. His main statement of the theory was given in a series of 20 lectures in 1858. The lectures were published in 1858 with the title Die Cellularpathologie in ihrer Begründung auf physiologische und pathologische Gewebenlehre (Cellular Pathology as Based upon Physiological and Pathological Histology), which is one of the most important books in the history of medicine. It was the foundation stone and first real scientific paradigm of pathology.

The use of the microscope and the era of Rudolf Virchow enabled the creation of a school of cell-based anatomic pathology, which made possible a series of important discoveries—and, moreover, built the basis of modern histopathology.

Some key persons

Johannes Peter Müller (1801–1858)

Johannes Peter Müller, who has become one of the most distinguished physiologists of Germany, was born in Koblenz into a shoemaker’s family on July 14, 1801. Educated in the faith of the Catholic Church, he entered a Latin seminary of the Jesuits. At first, Müller wanted to start a life path as a Roman Catholic priest. Nevertheless, he got interested in medicine and finally entered the University of Bonn in 1819, where he graduated in 1822. In 1824, he was granted a lectureship in physiology and comparative anatomy at the University of Bonn. In his inaugural lecture, Physiology, a science in need of a philosophical view of nature, he outlined his approach to science and maintained that the physiologist must combine empirically established facts with philosophical thinking. Two years later he was appointed associate professor, and in 1830 he advanced to the position of a full professor. In 1833, he moved to Berlin to chair the Department of Anatomy and Physiology until his death on April 28, 1858. Between 1833 and 1840, he published his tremendous Handbuch der Physiologie des Menschen (Elements of Physiology). In this book, Müller presented results of comparative anatomy, chemistry, and physics. In consequence, applying the microscope for the investigation of physiological problems was revolutionary.

In 1833, Müller succeeded the professorship of Karl Rudolphi. His lectures in Berlin, which were published as Handbuch der Physiologie des Menschen obtained then special attention. Today it is said that this book was the starting point for understanding life processes in a more mechanistic way. A concept that was widely accepted later in the 19th century.

Furthermore, Müller became interested in pathology by the discovery of his assistant, Theodor Schwann, that the cell was the basic unit of structure in the animal body. After his studies on tumors, he published in 1838 the results in his famous book Über den feineren Bau und die Formen der krankhaften Geschwülste (On the Nature and Structural Characteristics of Morbid Growths).

Later in his life he chiefly devoted himself to comparative anatomy. Müller was a gifted teacher and mentored distinguished scientists and physiologists such as Hermann von Helmholtz, Emil du Bois-Reymond, Theodor Schwann, Friedrich Gustav Jakob Henle, Carl Ludwig, and Ernst Haeckel. In 1834, he was elected a foreign member of the Royal Swedish Academy of Sciences. Müller died in Berlin in 1858.

Theodor Schwann (1810–1882)

Schwann was born in Neuss on the Rhine, a few miles from Cologne. He received an excellent training in mathematics and physics at the Jesuits College and started to study medicine in 1829. Schwann received his MD in 1834 in Berlin and learned anatomy, physiology, and general pathology from Johannes Müller (1801–1858). During these years spent under the influence of Müller, Schwann’s most valuable work was done. At that time, Müller was preparing his book on physiology, and Schwann assisted him in performing the required experiments. Schwann observed animal cells under the microscope, noting their different properties. He discovered the striated muscle in the upper esophagus and isolated an enzyme essential to digestion, which he called pepsin.

In 1839 Schwann chaired the Department of Anatomy of the University of Leuven. In 1848 he moved to the University of Liège. Three years after retiring, Schwann died in Cologne on 11 January 1882.

Carl Rokitansky (1804–1878)

Rokitansky (Fig. 2) was one of the towering figures in the history of pathological anatomy. Karl Freiherr von Rokitansky was born on February 19, 1804, in Königgrätz (today Hradec Králové, Bohemia, Czech Republic) and died on July, 23, 1878, in Vienna, Austria. He studied in Prague and Vienna and started his career in the morgue of the Allgemeine Krankenhaus in Vienna in 1827. Two years after his graduation in 1828, he became a paid assistant. Together with the Bohemian Josef von Škoda (1805–1881) and the Moravian Ferdinand Hebra (1816–1880), he was at the heart of the so-called New Vienna School of the former Austrian Empire. Rokitansky was the first to gather pathological changes in human organs in a systematic and exhaustive manner. He carefully considered the structure of morphology in comparison with clinical symptoms and its potential pathophysiological development. In that way, he fulfilled Morgagni’s fundamental idea of the Seats and Causes of Disease in the 18th century. Contrary to the hospitals in Paris, where every clinician was his own prosector, Rokitansky had overviewed more than 50,000 autopsies as a full-time pathologist. Rokitansky firmly established the New or Second Vienna School by stressing the importance of pathological study by correlation of clinical symptoms with signs of structural abnormalities observed at autopsy. His kind of work made him the best descriptive pathologist of his days and prompted Rudolf Virchow (1821–1902) to refer to him as the Linné of pathological anatomy.

But it was also Virchow who criticized Rokitansky’s theory of crases and exsudates in his textbook of pathology. After performing a huge number of autopsies, Rokitansky was not able to find a cause of death or any significant morphological change. He therefore fell back on the idea of humoral pathology of antique Greece medicine, whereby it was believed that diseases might also be caused by a wrong mixture of bodily fluids. Virchow shot down Rokitansky’s Krasenlehre as an anachronistic idea not worthy of a pioneer such as Rokitansky was. In his day, Rokitansky was restricted to what the naked eyes were able to recognize, and thus he reached the limits of gross perception. Virchow broadened this horizon by the possibilities of the microscope. Although Rokitansky did not master the microscope personally, he used his influence to support histological and pathophysiological studies. However, the number of original pathological-anatomical observations by Rokitansky is enormous. He was, for example, the first to differentiate between lobar and lobular pneumonia (bronchopneumonia), described acute yellow atrophy of the liver (1843), the patent ductus arteriosus as a congenital lesion (1864), endometriosis (1860), typhoid fever, goiter (1849), and various tumors (1852/53/54) and cysts (1849/54). He recognized the periarteritis nodosa and called it diathesis aneurysmatica (1851). Rokitansky was the first to discover bacteria in endocarditis and differentiated Bright’s disease from amyloid degeneration of the kidney. In 1851 and 1875, he wrote outstanding contributions on the diseases of arteries and on congenital defects of the heart, On Some of the Most Important Diseases of the Arteries and The Defects in the Septum of the Heart. Many of his inputs in pathological anatomy eternalized him partly by carrying his name as eponym. The pioneering work of Rokitansky established pathology as a recognized specialty and, thus, in 1844 he was appointed to full professor. In addition, the old morgue that Adolf Kußmaul (1822–1902) called a paltry shack was replaced 1862 by a new building that comprised a new dissection room, various laboratories, and a pathological museum [17,18,19].

Rudolf Virchow (1821–1902)

Rudolf Carl Virchow (Fig. 3) was born 1821 in Schivelbein (Pomerania, Prussia; now Świdwin, Poland) and moved up to be one of the most prominent pathologists and physicians of the 19th century. He pioneered the modern concept of diagnostic pathology and created the modern scientific paradigm by its application of cell theory to explain the effects of disease. Besides his contributions as a pathologist, he became an influential statesman of the liberal party in Germany. Along this line, he campaigned vigorously for social reforms.

In 1839, Virchow began the study of medicine at the Friedrich Wilhelm Institute of the University of Berlin, and graduated as a doctor of medicine in 1843. After Virchow was appointed prosector at the Charité, he began in 1847 to publish the famous Archives for Pathological Anatomy and Physiology, and for Clinical Medicine.

Early in 1848, Virchow was commissioned by the Prussian government to investigate an outbreak of typhus fever in Upper Silesia. His subsequent report laid the blame for the outbreak on social conditions and on the government. In 1849, Virchow was appointed to the newly established chair of pathological anatomy at the University of Würzburg, which was the first chair of that subject in Germany. During the 7 years in that post, a number of students who later attained fame in the medical field received training there from him. In 1850 he married Rose Mayer and had three sons and three daughters with her. At Würzburg, Virchow wrote his six-volume Handbook of Special Pathology and Therapeutics, and he also began to formulate his theories on cellular pathology.

In 1856, a chair of pathological anatomy was established for Virchow at the University of Berlin. In 1861, Virchow was elected to the Prussian Diet and was a founder of the Fortschrittspartei (Progressive Party).

Although Virchow is mainly known for his cellular pathology, he also shed new light on the process of inflammation, whereas he erroneously rejected the possibility of migration of leukocytes. He distinguished between fatty infiltration and fatty degeneration, and he introduced the modern concept of amyloid degeneration. He devoted great attention to the pathology of tumors, but the importance of his published manuscripts on malignant tumors and of his three-volume work on that subject (Die krankhaften Geschwülste, 1863–67) was diminished by his erroneous conception that malignancy might result from a conversion (metaplasia) of connective tissue. This standpoint led to a practical controversy with Waldeyer-Hartz (1835–1921) in the particular case of the illness of the emperor Frederick III [20]. His work on the role of animal parasites, especially trichina, in causing disease in humans was fundamental and led to the public interest in meat inspection. In 1874, he introduced a standardized technique for performing autopsies, in which the whole body was examined in detail, often revealing unsuspected lesions.

Regarding the upcoming science of bacteriology, he was rather skeptical as to whether bacteria might cause disease. He believed and suggested that some bacteria might produce toxic substances resulting in symptoms and that bacteria would not pathogenic by themselves.

Another field of interest for Virchow was anthropology. In 1865, Virchow discovered pile dwellings in northern Germany, and in 1870 he started to excavate hill forts. In 1869, he was part founder of the German Anthropological Society, and in the same year he founded the Berlin Society for Anthropology, Ethnology, and Prehistory, of which he was president from 1869 until his death. During the whole of that period, he edited its Zeitschrift für Ethnologie (Journal of Ethnology). In 1874, Virchow met Heinrich Schliemann, the discoverer of the site of Troy, and he accompanied Schliemann to Troy in 1879 and to Egypt in 1888 [21, 22].

In 1873, Virchow was elected to the Prussian Academy of Sciences. He declined to be ennobled as “von Virchow,” but in 1894 he was made Geheimrat (privy councillor) [23, 24]:

Influences from outside Central Europe

Aside the Aristotelian & Kantian movement working as a “locomotive” in Central Europe, there were, of course, other spots of evolving scientific thinking that contributed to the basis of modern histopathology, e.g., in Italy (especially Padua), France, England, Spain, and Portugal. Outside Europe, e.g., in the United States, there developed the idea of pragmatism. William James (1842–1910), Charles Sanders Peirce (1839–1914; sometimes called the “father of pragmatism”), and John Dewey (1859–1952) were its key figures. Peirce coined a rule later called by him the “Pragmatical Maxim” (deliberately based on Kantian Categorical Imperative!):

“Consider what effects, that might conceivably have practical bearings, we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object” [25]. William James exerted Peirce’s ideas on human acting and brought them close to the utilitarianism that Peirce declined, and re-named his concept “pragmaticism.” Nevertheless, that misinterpretation led in consequence, that such new utilitarian pragmatism views science and even medicine in terms of the practical use and success. A viewpoint that became quite popular in American societies. Formulating such utilitarian interpretation to the extreme, one might say that European pathologists or even thinkers may be in love with theory and nomenclature, whereas Americans tend to view anything by its practicability and usage.