Emergence of Biological Systematics: Anti-Scholastic Revolution

In the second half of the 18th century, a decisive role in the conceptual history of systematics is played by a new turn in the development of natural science, largely

It is noteworthy that Linnaeus himself is the first to designate his achievements as “Linnaean reform” in his autobiography [Bobrov 1970].

predetermined by a combination of the ideas of English philosophical empiricism and French Enlightenment. In the branch of natural history associated with the study of living nature and of which systematics is an important part, a new “biophilosophy” begins to emerge. It is based on a fundamentally new understanding of the organism— not as a set of essential or diagnostic characters, but as a complexly organized developing living being interacting with its natural environment. Detailed anatomical, histological, and physiological studies of animals and plants, including comparative embryological ones, become of great importance as suppliers of new kinds of data. The emergence of the term “biology” (its authors are G. Treviranus and J.-B. Lamarck) signifies an acknowledgment of the important border between living and inanimate natures, so the old scholastic universal systematics gives a way to a new, actually biological one [Stafleu 1969; Wilkins 2009; Pavlinov 2018].

All this means nothing more than the “biologization” of systematics, and its new content and tasks can be summarized in the following main positions. First, to reveal the natural orderliness of living nature, it is necessary to recognize the natural groups of plants and animals as dictated by their nature instead of construing artificial “Ariadne’s threads” following a formal classification algorithm. Secondly, since the System of Nature is a plurality of interrelations of “all with all” (one of Leibniz’s ideas), it is necessary to distinguish natural groups by many characters. Further, the latter should be uncovered as a result of empirical research instead of pre-assigning them certain “weights” based on ideas about essences. Finally, the classification algorithm should be not divisive (deductive), but agglomerative (inductive): one should not divide higher “genera” into lower ones, but start at the species level and then sequentially unite species into assemblages of higher ranks. All this together provides a new understanding of the natural method of systematics implementing, with significant delay, one of the key conditions of natural science established at the end of the 16th century: it should be empirical in its base.

New ideas set a significantly new trend in the conceptual history of systematics. The shift from an “old” to a “new” systematics in the late 18th and early 19th centuries deserves the designation anti-scholastic revolution dividing scientific systematics into scholastic and post-scholastic stages [Pavlinov 2018, 2019]. The classic writer on botany of the early 19th century, A.-P. de Candolle, equates it with the revolution in chemistry made at the end of the 18th century by the analytical chemist Antoine Lavoisier [de Candolle 1819]. In botanical historiography, this transition is usually designated as the end of the epoch of “artificial systems” and the beginning of the epoch of “natural systems” [Lindley 1836; Sachs 1906; Starostin 1970; Uranov 1979; Stevens 1994, 1997]; in fact, all post-scholastic systematics should be called “natural” in the most general sense.

The second scientific revolution in systematics, being anti-scholastic, becomes to an extent also “anti-Linnaean.” Leading experts of systematic botany of the first half of the 19th century, evaluating its first results, accentuate enthusiastically that systematics did not remain limited to the Linnaean (actually, scholastic) formal method of identifying species and genera with a few diagnostic features, but went further to become the science of “exhaustive characterization” [Sprengel 1808; Brown 1810; de Candolle 1819; Lindley 1836]. Later, the historian of botany Julius von Sachs will join this critical assessment by emphasizing that if Linnaean systematics had triumphed, “the inevitable result was that botany ceased to be a science,” while the truly natural systematics that began to take shape in France “proved to be the only one endowed with living power, the true possessor of the future” [Sachs 1906: 108, 110]. The method of natural systematics will be hailed as a new “philosophy of botany” [Drouin 2001].

The empiricism of post-scholastic systematics develops not in a strict Lockean, but no less in the rational Cartesian style, i.e., it emerges as rational-empirical systematics. The latter means that the basis of the new rationality, like the previous one, is the belief in the Method (Organon), i.e., the very natural method that allows “methodists” to reveal a sought “nature of things.” In its new interpretation, such a method “must be based on the nature of organisms, which includes a totality of all their features and structures” [Adanson 1763: civ], and this method “must be universal, or unified, that is, there should be no exceptions for it” [Adanson 1763: civ]. An important part of this rationality becomes a separation of the “System” from the “Method”: the first is equated with the scholastic (Linnaean) “artificial system,” while the second is acknowledged in a new empirical meaning as the “natural order” corresponding to the true “nature of things” [Stevens 1994; Pavlinov 2018]. The need for a new conceptual design of biological systematics and its natural method, as opposed to the previous scholastic one, stimulates a purposeful interest in the development of its theoretical foundations. So, at the beginning of the 19th century, a theoretical section of this discipline, taxonomy, is delineated and denoted [de Candolle 1819; DeCandolle and Sprengel 1821], followed by articles especially devoted to the illumination of new methodological principles of systematics [Jussieu 1824; Strickland 1841].

This new rationality of biological systematics, with its emphasis on the use of a large number of characters, becomes fixed terminologically. The botanist Charles-François Brisseau de Mirbel, in the first volume of his “Natural History of Plants” [Brisseau-Mirbel 1802], suggests calling the new multi-character method polytypic, in contrast to the monotypic single-character method of scholastics; later they will be denoted as polythetic and monothetic, respectively [Sokal and Sneath 1963].

The beginning of the post-scholastic stage in the conceptual history of systematics dates back to the mid-end of the 18th century, with representatives of the French Enlightenment playing the most active role. Its initiation is undoubtedly marked by the publication of the two-volume “The Families of Plants” by botanist Michel Adanson: the above quotation from him most clearly expresses, for the first time, a fundamental idea of the natural method in its new understanding, supplemented by a new “natural order” of plants [Adanson 1763]. Thus, an initial phase of the antischolastic revolution deserves being called Adansonian, by analogy with the beginning of the scholastic revolution, called above Cesalpinean. However, the novelty of the technical implementation of Adanson’s method turns out to be too radical: it is based on the analysis of all available characters and justifies natural groups by specific combinations of most compatible ones. Therefore, in the early post-scholastic systematics of the late 18th to early 19th centuries, a more conservative approach of Jussieu, rooted in rather traditional ideas about essential features, will prevail over that of Adanson (see Section 2.4.2).

The post-scholastic revolution in systematics, freeing it from the dictate of scholastic procedures, leads to the emergence of a bunch of new research programs, each with its own understanding of the subject, tasks, and the natural method of systematics [Pavlinov 2018, 2019]. Thus, at the turn of the 18th and 19th centuries, two programs are almost simultaneously being shaped to take leading positions: natural systematics in its narrow, mostly botanical capacity (Jussieu, Candolle, Lindley, etc.) and typological systematics of zoologists (Vic d’Azir, Cuvier, Baer, etc.). A more peripheral position is taken by natural-philosophical concepts of a rather esoteric make-up, these are “biblical Platonism” (Agassiz, Owen), organismism (Oken), and numerism (MacLeay); to them undoubtedly should be added the idea of transformism, appearing ahead of its time (Lamarck). Most of the “taxonomic esotericism” will leave almost no trace in the subsequent conceptual history of systematics (albeit a noticeable though indirect impact of organismism on classical phylogenetics), typological and natural schools systematics will fade into the background, while transformism will take a leading position half a century later.

It is worth mentioning separately a version of natural systematics in its most general (natural-philosophical) understanding which focuses on “apparently natural” groups of plants. An idea of naturalness of such groups dating back to Theophrastus, in the period under consideration, is declared by one of the leaders of the Enlightenment, naturalist G.-L. Buffon. It is defended most insistently by the natural philosopher and naturalist Alexander von Humboldt, who believes that the Natural System cannot be built without taking into account the inseparable connection of organisms with their environment, w'hich is revealed by detailed investigations of their natural history. Accordingly, the Natural System of plants must include, first of all, obvious and clearly delineated ecological groups, such as grasses, bushes, trees, vines, etc.: such groups are designated by Humboldt as the “basic forms of life” [Humboldt 1806]. Active assimilation of this idea will begin at the end of the 19th and the beginning of the 20th centuries when a more developed concept of life forms will be elaborated follow'ed by the appearance of systematics of life forms (see Section 5.5).

 
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