From theory of ideas to theory of succedaneum: The Linnaean botanical nomenclature(s) as “a point of view on the world” Philippe Selosse 1. Introduction Botanical nomenclature did not arise by spontaneous generation: its elaboration is the continuation of the Greek and Latin folk nomenclature, which was based on processes of classification and categorization called folk processes (Berlin 1972), and of the logical nomenclature of the sixteenth century (Selosse 2004, 2007). On the whole, the elaboration of nomenclature took a great deal of time, more or less twenty centuries. The consequence is that nomenclature is not the fact of one speaker, but the product of many speakers over a very long period of time, connected with several epistemic contexts. Moreover, these contexts are characterized by non-specialization with regard to disciplines: philosophy, language and botanical research were simultaneously considered. The aim of this paper, therefore, is not to represent Linnaeus as a pioneer or a maker of binominal nomenclature out of nothing. On the one hand, Linnaeus ap- pears, not as person, but through his works, as the representative, the paragon, of the turning point in another epistemic context: his work constitutes a gen- uine synthesis of earlier theories and those that followed. On the other hand, the Linnaean nomenclature is, for the first time, one which is self-conscious, that is, which is conscious of being a system as such: in this scientific consciousness we can paradigmatically observe the articulation of plant classification in nomen- clature, and vice versa. My aim is to draw from Linnaeus’ works his theory of nomenclature within the epistemic context of the Enlightenment, that is, by taking into consideration its own complexity of blended scientific, philosophi- cal and linguistic conceptualizations. My hypothesis depends on the use of the Latin word “succedaneum”, which is almost synonymous with “substitute”: a succedaneum is a thing taking the place of another. The word “succedaneum” was used in particular in pharmacopoeias, where it applied to a drug substi- tuted for another because they shared common properties, even if the second DOI 10.1515/9783110255065.157, ©2017 Philippe Selosse, published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License. 158 Philippe Selosse was more complete, appropriate and natural than the first. “Succedaneum”1 fre- quently occurs in Linnaeus’ hundreds of aphorisms, not with medicinal but with conceptual applications. In my view, the concept of succedaneum allows us to understand the unity of these hundreds of aphorisms2, that is, how the various taxonomic and linguistic concepts are conceived in a homogeneous epistemic frame. 2. The theory of ideas The period of the Enlightenment is characterized by a semiotic theory, later called the theory of ideas (Auroux 1979), and developed by many philosophers, such as Locke, Leibniz and the Encyclopedists (Beauzée, Rousseau). Accord- ing to this nominalist theory of representation, we, unlike God, have no direct perception of a thing: we merely perceive the idea of a thing, an objective but incomplete idea, which is given by the name.3 The nomenclature also appears as a representation of the “nominal essences” (Locke 1755), conceived in the mind but founded in reality. One of the first and main Linnaean aphorisms refers to this theory: “Knowledge consists in having a true idea of things”4. In this epis- temic frame, Linnaeus considers the idea as a go-between, and that is why he says that “plant and name are two ideas”5: the name simply refers to an idea, which is related to another idea, the idea of the plant. Hence, the name does not mean – but refers to – the essence, conceived as the idea of a character connected to its own idea (see Figure 1). Figure 1. The theory of ideas In this way, it is permissible for a generic name to be drawn out from a proper name: a proper name does not signify the essence of the plant, it is just the idea 1. I keep the Latin word in my paper instead of an English word such as substitute, for it was often used in English from the beginning of the seventeenth century, especially in medicine and botany, with the meaning previously defined. 2. To understand the unity of these aphorisms in another perspective, see Han-Liang Chang’s article in this volume (section 5.2). 3. Cf. Linnaeus’ poem The Real, translated into English by Pr. Pettersson: “all that we see are shadows of reality”. 4. “Notitia consistit in vera idea objectorum” (Linnaeus 1735: § 10; italics mine). In this paper, all Linnaean quotations are given in my own translation. 5. “Nomen et planta sunt duae ideae” (Linnaeus 1737: § 238). From theory of ideas to theory of succedaneum 159 of a man, a botanist or a king linked by convention to the idea of the character of the plant. That is to say, the arbitrary human idea carried by the name is a substitute for (or succedaneum to) the natural idea suggested by the plant. This theory of ideas explains one aim of the Species Plantarum,whichis “to cover all the peculiar Ideas and to distinguish them by distinct Names,so that we can know God’s works”6. These ideas, created by God (Linnaeus 1735: § 14; Linnaeus 1736b: § 157) and referred to by distinct names, are two sorts of entities: species and genus. Being divine, their essences are perceived by God, but not by botanists, who only can distinguish or discriminate between them. Hence, species and genus are simultaneously natural (they are created by God) and artificial (they are represented through human perception). For all these reasons, the plant in itself cannot be known. At worst, a botanist discriminates a plant only thanks to a “factitious”, i.e. practical and artificial, character (Linnaeus 1751: § 188); at best, he might manage to discriminate the “essential” character of the plant (Linnaeus 1751: § 187). But in general, he only perceives, simultaneously and indiscriminately, the essential and acciden- tal properties of a plant, that is, a blending of factitious and essential characters, named “natural character” (Linnaeus 1751: § 189). To sum up, “the Factitious Character is the succedaneum”7 to the natural character, which is itself the suc- cedaneum to the essential character. 3. The concept of “disposition” Linnaeus does not use the term “classification”. He speaks very often of “dis- position”, that is, the manner of ordering the several specific and generic ideas. According to his concepts of species, genus and character, he distinguishes three sorts of dispositions8 : – To the worst degree, there is the “synoptic disposition” (Linnaeus 1736b/ 1751: § 154). This is a method based on a descending practice of logical di- vision. Logical division is an Aristotelian metaphysical method to define the essence, in a dichotomous way: something is defined by a genus and its dif- ference, the whole (genus and difference) being a species, which becomes a genus at the following step of division of the definition, and so on, down to 6. “cognitionem horum ut rite acquiramus, singula distincta Idea & distincto Nomine complecti oportet” (Linnaeus 1753: Lectori Aequo; italics and block capitals in the original). 7. “Character Factitius succedaneus est” (Linnaeus 1751: § 190). 8. Cf. Richard Sörman’s paper in this volume (section 4). 160 Philippe Selosse the ultimate species, which involves essence and individuals. As an example (see Figure 2, after Bauhin 1623: 187), we can see how this division is applied to the genus Gentiana in the sixteenth century, so that the different species of Gentian are all given by a dichotomous or trichotomous division. At the first step of this division, three species are defined by differences of habitat: the Alpine Gentian, the Meadow Gentian and the Marsh Gentian. Inasmuch as it is itself divisible, the species Alpine Gentian is given as a genus containing two species, defined by differences of height: the Greater Alpine Gentian and the Lesser Alpine Gentian. At the ultimate step of division, the species Greater Alpine Gentian becomes a genus, containing in its turn two species, defined by differences of colour: the Yellow Greater Alpine Gentian and the Purple Greater Alpine Gentian. This kind of disposition is conceived by Linnaeus as arbitrary (to proceed with the logical division, it was necessary only to choose a good criterion, whatever it might be: habitat, height, colour, frequency…) and artificial (it is a logical method applied to natural beings), and as pertaining to practical knowledge (Linnaeus 1751: § 152). Primary genus GENTIANA Difference anipla sisnetarp sirtsulap Species/Intermediate Genus GENTIANA ALPINA GENTIANA PRATENSIS GENTIANA PALUSTRIS Difference rojam ronim Species/Intermediate Genus GENTIANA ALPINA MAJOR GENTIANA ALPINA MINOR D ecnereffi aetul aeruprup Ultimate Species Gentiana alpina major lutea Gentiana alpina major purpurea Figure 2. Logical division applied to the genus Gentiana (after Bauhin 1623: 187) – To a better degree, there is the “system” or “artificial method” (Linnaeus 1736b: § 155–156). This is a method based on a descending practice (often il- lustrated by keys), which is characterized by using the same single principle for all the plants (Lamarck 1792: 301). The Linnaean sexual system is an example of this sort of disposition: it is based on the single principle of the physiological importance of plant sexuality, considered from various points of view (place, figure, proportion and number of the plant reproductive organs). This disposi- tion is conceived as artificial (it is a rational human method applied to natural beings created by God) but not arbitrary (the importance of plant sexuality is From theory of ideas to theory of succedaneum 161 founded in reality and is not the result of a practical choice), and as pertaining to theoretical knowledge (Linnaeus 1751: § 152) – theoretical, because it is not the world but a representation of the world.