at a given moment in time (like getting grey as you get older); and one that occurs in one and only one species and at all times (like the ability to laugh in humans). This last type is the one most frequently cited and has the relatively interesting characteristic of being reciprocable with the species (only humans laugh and those who laugh are all human). Nevertheless, the proprium is not essential to the definition because laughter is only an occasional behavior, and therefore an “accident,” and does not characterize human beings in a constant and necessary manner.

Medieval tradition takes up this idea out of mere fidelity to the traditional example, just as all of modern logic assumes, without further verification, that the evening star and the morning star are both Venus.

We are ignoring the fact that four-leggedness must be a proprium and not a difference, seeing that elsewhere two-leggedness is given as an example of a proprium.

For a clear and unequivocal clarification of this point, see Posterior Analytics (II, 13, 97a 16–25).

It might be objected that two-legged or not the sum are indeed differences, but not specific; but we saw a moment ago in Figure 1.4 that specific differences such as rational may also occur twice (at least) under different genera.

See Boethius (1998: 33).

And in 157, 15, it is repeated again that a given difference can be predicated of more than one species: “Falsum est quod omnis differentia sequens ponit superiores, quia ubi sunt permixtae differentiae, fallit” (“It is false that every successive difference presupposes those that come before it, for that rule does not hold true in cases where the differences are mixed”).

“In rebus enim sensibilibus etiam ipsae differentiae essentiales ignotae sunt, unde significantur per differentias accidentales, quae ex essentialibus oriuntur, sicut causa significatur per suum effectum, sicut bipes ponitur differentia hominis” (“Even in the case of sensible things we do not know their essential differences; we indicate them through the accidental differences that flow from the essential differences, as we refer to a cause through its effect. In this way ‘biped’ is given as the difference of man”), Aquinas (1983, ch. V, paragraph 6, p. 63).

See for instance the by now regrettably classic examples of Katz and Fodor (1963) or Katz (1972). For these problems, and for further references to the very extensive bibliography on the subject, see Eco (1984a: ch. 2) and Violi (1997 [English trans. Violi 2001]).

For a comprehensive historical survey, see Foucault (1966), Collison (1966), Binkley ed. (1977) (in particular the essay by Fowler), Beonio-Brocchieri Fumagalli (1981), Cherchi (1990), Schaer (1996), Salsano (1997), and Pombo et al. (2006) (and all Pombo’s contributions on the Internet).

Enkyklios does not really mean, as it is usually translated today, “circular” education, in the sense of harmoniously complete, so much as “in the circle.” Aristotle, in his Nicomachean Ethics and in the De coelo uses the adjective to mean “usual,” “ordinary,” in the meaning of “recurrent.” But, according to some interpreters, the adjective refers to the form of the chorus: learning to sing certain hymns was an essential part of a boy’s education, and therefore enkyklios would mean “the kind of education that a boy should have received.” In fact this is the sense in which Vitruvius (De architectura, VI) interprets it, as “doctrinarum omnium disciplina,” (“the disciple of all knowledge”) and likewise Quintilian in Institutio oratoria (I, 10).

English translation: Rabelais (2006: 48–49).

Cf. West (1997) for the idea suggested in Vives’s De disciplinis of the encyclopedia as a constant expansion of information as a result of after-dinner conversation.

“Captive Greece took captive her savage conqueror” (Horace, Epistolae 2, 1, 156).

These points will be further developed in Chapter 3 of the present volume.

Biblical quotes, here and elsewhere, are from the King James Version.

English translation: Curley (1979: 15–16).

If we find this order disconcerting, all we have to do is to consult, let’s say, an Italian elementary school textbook from the 1930s containing scraps of ancient Roman history and the history of the nineteenth-century Risorgimento (skipping from Julius Caesar to Garibaldi), snippets of arts and literature (in the form of portraits of great men of the past), various lessons concerning life on the farm, notions of Fascism, a rudimentary introduction to racism. Anyone approaching such a text today with a scientific mentality would be unable to grasp the logic of its composition, but it contained all that the elementary school teacher was expected to impart as indispensable to the education of a child. Furthermore, if we were to compare the various morning schedules of a modern liceo or high school, we would be faced with incomprehensible leaps from organic chemistry to philosophy, from square roots to Petrarch. Or think again of the vagabond structure of many encyclopedias for children.

For the encyclopedic projects of the Renaissance and beyond, see the various contributions of Tega (1983, 1984, 1995, 2000, 2004), Vasoli (1978) and Pombo et al. (2006). For the Theaters of the World, cf. Rossi (1960) and Yates (1966).

A scholar who, in the Baroque period, and precisely in the name of the pansophical ideal, will partially succeed in fleshing out his index is Jan Amos Komensky. With a general reform of society in mind and with an eye to implementing fresh pedagogical forms, in his Didactica magna (1628) and Janua linguarum (1631), to give the student an immediate visual apprehension of the things he was learning, Komensky attempted to classify the elementary notions according to a logic of ideas (the creation of the world, the four elements, the mineral, vegetable, and animals realms), while in his Orbis sensualium pictus quadrilinguis (1658) he devised a detailed illustrated nomenclature of all the world’s fundamental objects as well as of human actions.

Proemium, Epistle Dedicatory, Preface, and Plan of the Instauratio Magna by Francis Bacon, in Eliot (1909, vol. 39, p. 126).

The last words of the title (vere, ut dicitur, muto) are probably a play on words, since, according to Schott, the author was dumb (muto), and in Castilian Bermudo is pronounced almost the same as Ver-mudo (cf. Ceñal 1946).

Leibniz will discuss the inappropriateness of this arrangement by classes in his early work, Dissertatio de arte combinatoria (1666).

Mss. Chigiani I, vi, 225, Biblioteca Apostolica Vaticana; see Marrone (1986).

For the Geometric Finger, see Eco (1996a: 96).

English translation: D’Alembert (1963: 46–49).

English translation: Dante (1982: Paradiso XXXIII: 85–96).

In this labyrinth, by the way, there has to be a Minotaur, just to make the experience interesting, seeing that the pathway through it (setting aside the initial disorientation of Theseus, who doesn’t know where it will lead) always leads where it has to lead and can’t lead anywhere else.

In this case there is no need for a Minotaur; the Minotaur is the visitor himself, misled as to the nature of the tree.

The first proposals for switching to encyclopedic representations are to be found in Wilson (1967). There followed Eco (1975), Haiman (1980), Eco (1984a), Marconi (1992, 1999), and Violi (1997).

This was the topic of the seminar in which Chapters 2 and 3 in this volume had their origin. Its purpose was to attempt to establish how and to what extent Aristotle’s proposal had been accepted throughout history. For a complete overview reaching down to the present day, see the miscellany edited by Lorusso (2005), in which, for the analysis of the Aristotelian texts, we refer the reader to the contributions of Manetti (2005), Calboli Montefusco (2005), and Calboli (2005).

On the fact that metaphor constructs rather than discovering a similarity and is a source of fresh knowledge, not so much because it makes us know a given thing better but above all because it makes us discover a new way of organizing things, see, in addition to Black, Ricoeur (1975: 246) and Lakoff and Johnson (1980: 215).

It will be observed how this reconstruction of a fragment of encyclopedia within Joyce’s text was reminiscent of the model in Quillian (1968), adopted in Eco (1975).

Pavel (1986: 64–70).

On the Metrôon as a warehouse of memory, see Esposito (2001: 107–110).

It has been suggested that the concept of a semiotic encyclopedia corresponds to Lotman’s idea of the semiosphere: “Imagine a room in a museum, where exhibits from different eras are laid out in different windows, with texts in known and unknown languages, and instructions for deciphering them, together with explanatory texts for the exhibitions created by guides who map the necessary routes and rules of behaviour for visitors. If we place into that room still more visitors, with their own semiotic worlds, then we will begin to obtain some thing resembling a picture of the semiosphere” (Lotman 2005: 213–214). In point of fact Lotman’s semiosphere would appear on the one hand to be still vaster than a Maximal Encyclopedia because it also contains the private and idiosyncratic notions of the individual visitors; on the other hand, it is, so to speak, regulated by someone (the organizers) and therefore appears rather to be the territory of a culture that has set up rules to distinguish a Median Encyclopedia from the Specialized Encyclopedias.

[Translator’s note: On Gesualdo, among others, see Barbara Keller-Dall’Asta, Heilsplan und Gedächtnis: zur Mnemologie des 16. Jahrhunderts in Italien (Heidelberg: Universitätsverlag Winter, 2001).]

The work of Johannes Spangenberg appeared under this title in 1570, but another version with the title Libellus de comparatione artificiosae memoriae had appeared in 1539. It would be subsequently published as Artis memoriae seu potius reminiscentiae in 1603, Ars memoriae in 1614, etc.

To these causes we might add the mystics’ techniques for detachment from the world and from one’s own memories. These are certainly techniques that aim at voluntary forgetfulness, but what is to be forgotten is so global as to coincide with the annihilation of one’s own