20. To complicate things further, another element comes into play. Medieval thought is to put it mildly obsessed with two objects of investigation, God and man. Observe what happens in the theory of definition from Porphyry’s Isagoge down to Ockham. Porphyry’s tree ought to be seen as a logical artifice that permits us to define every element of our cosmic furniture, but in fact it is invariably exemplified in abbreviated form, in such a way as to distinguish unequivocally man from the divinity. As we observed in Chapter 1, none of the available examples of the Arbor Porphiriana serves to define unambiguously the horse or the dog, to say nothing of plants and minerals. Irrational animals find a place there only to furnish a pole of comparison with the rational animals. Whereupon the medieval theory of definition leaves them to their fate and fails to provide pointers for distinguishing a dog from a horse, let alone a dog from a wolf. In order to have adequate taxonomical instruments at our disposal, we must await the naturalists and theorists of artificial languages of seventeenth-century England (see Slaughter 1982 and Eco 1993).
21. I refer the reader to the chapter on “Signs” in Eco (1984b: 14–45), which was based on my entry “Segno” in volume 12 (1981) of the Enciclopedia Einaudi. See also Todorov (1982).
22. “For a sign is a thing which, over and above the impression it makes on the senses, causes something else to come into the mind as a consequence of itself: as when we see a footprint, we conclude that an animal whose footprint this is has passed by; and when we see smoke, we know that there is fire beneath; and when we hear the voice of a living man, we think of the feeling in his mind; and when the trumpet sounds, soldiers know that they are to advance or retreat, or do whatever else the state of the battle requires. Now some signs are natural, others conventional. Natural signs are those which, apart from any intention or desire of using them as signs, do yet lead to the knowledge of something else, as, for example, smoke when it indicates fire. For it is not from any intention of making it a sign that it is so, but through attention to experience we come to know that fire is beneath, even when nothing but smoke can be seen. And the footprint of an animal passing by belongs to this class of signs. And the countenance of an angry or sorrowful man indicates the feeling in his mind, independently of his wilclass="underline" and in the same way every other emotion of the mind is betrayed by the tell-tale countenance, even though we do nothing with the intention of making it known. This class of signs, however, it is no part of my design to discuss at present. But as it comes under this division of the subject, I could not altogether pass it over. It will be enough to have noticed it thus far. Conventional signs, on the other hand, are those which living beings mutually exchange for the purpose of showing, as well as they can, the feelings of their minds, or their perceptions, or their thoughts. Nor is there any reason for giving a sign except the desire of drawing forth and conveying into another’s mind what the giver of the sign has in his own mind. We wish, then, to consider and discuss this class of signs so far as men are concerned with it, because even the signs which have been given us of God, and which are contained in the Holy Scriptures, were made known to us through men—those, namely, who wrote the Scriptures. The beasts, too, have certain signs among themselves by which they make known the desires in their mind. For when the poultry-cock has discovered food, he signals with his voice for the hen to run to him, and the dove by cooing calls his mate, or is called by her in turn; and many signs of the same kind are matters of common observation. Now whether these signs, like the expression or the cry of a man in grief, follow the movement of the mind instinctively and apart from any purpose, or whether they are really used with the purpose of signification, is another question, and does not pertain to the matter in hand. And this part of the subject I exclude from the scope of this work as not necessary to my present object” (Augustine, On Christian Doctrine, II, 1–3, online trans. by J. F. Shaw, from Select Nicene and Post-Nicene Fathers, at http://www.ccel.org/ccel/augustine/doctrine.iv.iii.ii.html). On the doctrine of the sign in Augustine, see Manetti (1987), Vecchio (1994), and Sirridge (1997).
23. “Liquet autem ex suprapositis significativarum vocum alias naturaliter, alias ad placitum significare. Quecumque enim habiles sunt ad significandum vel ex natura vel ex impositione significative dicuntur. Naturales quidem voces, quas non humana inventio imposuit sed sola natura [contulit], naturaliter [et non] ex impositione significativas dicimus, ut ea quam latrando canis emittit, ex qua ipsius iram concepimus. Omnium enim hominum discretio ex latratu canis eius iram intelligit, quem ex commotione ire certum est procedere in his omnibus que latrant. Sed huiusmodi voces que nec locutiones componunt, quippe nec ab hominibus proferuntur, ab omni logica sunt aliene” (Petrus Abaelardus, Dialectica, First complete edition of the Parisian manuscript, With an introduction by L. M. De Rijk, Ph.D., Second, revised edition, Assen: Van Gorcum 1970, p. 114).
24. “Significare Aristotelis accipit per se intellectum constituere, significativum autem dicitur, quidquid habile est per se ad significandum ex institutione aliqua sive ab homine facta sive a natura. Nam latratus natura artifex, id est Deus, ea intentione cani contulit, ut iram eius repraesentaret; et voluntas hominum nomina et verba ad significandum instituit nec non etiam res quasdam, ut circulum vini vel signa quibus monachi utuntur. Non enim significare vocum tantum est, verum etiam rerum. Unde scriptum est: nutu signisque loquentur (Ovid, II Trist. 453). Per ‘significativum’ separat a nomine voces non significativas, quae scilicet neque ab homine neque a natura institutae sunt ad significandum. Nam licet unaquaeque vox certificare possit suum prolatorem animal esse, sicut latratus canis ipse esse iratum, non tamen omnes ad hoc institutae sunt ostendendum, sicut latratus est ad significationem irae institutus. Similiter unaquaeque vox, cum se per auditum praesentans se subgerat intellectui, non ideo significativa dicenda est, quia per nullam institutionem hoc habet, sicut nec aliquis homo se praesentans nobis dum per hoc quod sensui subjacet, de se dat intellectum, sui significativus dicitur, quia licet ita sit a natura creatus, ut hoc facere possit, non est ideo creatus, ut hoc faciat. ‘Significativum vero magis ad causam quam ad actum significandi pertinet, ut sicut non omnia significativa actualiter significant, ita non omnia actu significantia sint significativa, sed ea sola quae ad significandum sunt instituta” (Logica “Ingredientibus,” Glosses on the Peri Hermeneias. In Bernhard Geyer, Peter Abaelards Philosophische Schriften, Münster, Aschendorff, 1927, pp. 335–336).