The juxtaposition of the manuals of Nechepsos and Thessalos is the key to understanding the process by which authoritative texts were transmitted and expanded upon. The legendary king Nechepsos along with the sage Petosiris were figures of great authority and were considered the pseudonymous authors of astrological writings devoted to omen astrology, horoscopic divination, medical astrology and numerological prognostication. This literary production is now lost, except for a number of fragments preserved by later authors.7 The bulk of the extant fragments, citations and quotations point to a compilation of contemporary Graeco-Egyptian astrological tradition circulating in Ptolemaic Egypt at the time of its composition, around the late second or even the first century BCE.8 Pseudonymous compendia inevitably recast older materials even as they preserved thematic continuities but they often introduced conceptual changes. Hence, another corpus of texts that are related in content was ascribed to Hermes Trismegistus rather than to Nechepsos or Petosiris and soon after these legendary figures were thought of as students of Hermes or as followers of the Hermetic teachings (Festugière, 1944: 102–4).

The information provided in the letter concerning the iatromathematical manual of Nechepsos is independently verified by several sources on account of both structure and content. According to Thessalos (DVH, proem. 6–7, p. 47 Friedrich = fr. 35 Riess), the manual contained twenty-four cures for the entire body with every condition connected with zodiacal signs through stones and plants. The surviving medical fragments of Nechepsos confirm Thessalos’ narrative, since they fall into two distinct thematic groups which explore the medicinal properties of stones and plants.9 As none of them refers to the stars, it is likely that the original work of Nechepsos included the medicinal properties of astral stones and plants and that later compilers omitted the astrological lore, being interested only in their properties. However, it is possible that several of these fragments did not belong to the original work of Nechepsos and were attributed to him because of his authoritative status at a later date.

The manual on the whole constituted a glossary, a lexicographical arrangement of the materials into twenty-four entries, one for each letter of the Greek alphabet.10 In the same manner, the first book of the Hermetic Kyranides, a Byzantine compilation of earlier works dated to the second century CE (Fowden, 1993: xviii, 87–8 and n. 57), arranges the marvelous powers of plants, birds, fish and stones in twenty-four alphabetical entries.11 Even though this alphabetical systematization reflects traditions of Hellenistic Mesopotamia, it also has links to Egyptian scribal exercises that organized bird and plant names into alphabetical order (Quack, 2003: 165, 182–4). Hence, onomastic organization of the material has also been applied to other compendia created in Lower Egypt, such as the plant lore included in pseudo-Democritus’ work Cheirokmēta, composed by Bolus of Mendes (in Plin., HN 24.160–6; see Gordon, 1997a: 136) (late 2nd cent. BCE), and the herbal tractate written by the first century CE lexicographer Pamphilus of Alexandria (Gal., Simpl.Med. 6, proem., pp. XI 792, 797–8 Kühn).12 The material contained in the aforementioned works was a compilation mostly of earlier written and oral data. Lacking coherence, this vast material was organized and systematized through alphabetization and schematic (re)arrangement (Gordon, 1997a: 131; idem, 1999: 235; idem, 2010: 268; idem, 2011: 51).

The medical prescription Thessalos unsuccessfully attempted to apply included the solar lozenge (trochiskos hēliakos), a remedy admired by Nechepsos himself (DVH, proem. 7, p. 47 Friedrich = fr. 35 Riess). A fragment from Nechepsos’ manual, quoted by the physician Aëtius of Amida (1.38, p. I 40 Olivieri = fr. 30 Riess), provides instructions for the making of lozenges composed of the plant anthemis, alias chamomile (Matricaria chamomilla L.),13 for the treatment of fever. When a fever occurs, a lozenge is to be pulverized, mixed with oil and then applied as an ointment throughout the whole body. Likewise, Dioscorides (Mat.Med. 3.137.3, p. II 147 Wellmann) notes that some use chamomile as a salve mixed with oil to cure intermittent fevers. The hot and dry properties of the plant in Aëtius’ excerpt (see also Gal., Simpl.Med. 6.1.47, p. XI 833 Kühn; cf. Dsc., Mat.Med. 3.137.2, p. II 146 Wellmann; Gal., Simpl.Med. 3.10, p. XI 562 Kühn) intrinsically relate it to the Sun in view of the fact that the Sun in antiquity was thought to have exactly the same qualities as chamomile (Ptol., Tetr. 1.4.1, p. 22 Hübner ~ Heph.Astr., 1.2.2, p. I 31 Pingree). This association is explicitly stated by Galen (Simpl.Med. 3.10, p. XI 562 Kühn), according to whom the wisest of the Egyptians had consecrated chamomile to the Sun and considered it to be a remedy for every kind of fever. That the solar lozenge in Thessalos’ narrative was part of Nechepsos’ prescriptions is further suggested by pseudo-Apuleius (Herb. 23, p. 62 Howald and Sigerist), who used the synonym ‘solar lozenge’ (trociscos eliacos) for chamomile. In light of this information, it can be assumed that Thessalos was familiar with the content of the treatise ascribed to Nechepsos.

Nechepsos’ solar lozenge introduces us to the ways in which ancient astrologers selected and organized the vast and varied rhizotomic material in literary schemes. The Hermetic discourses of pharmacopoeia press into service plants that are thought to be associated with their corresponding stars or planets through sympatheia.14 Such systematization quantitatively distinguishes the properties of the plant material according to the geographical region from which it was picked. This organizing principle is expounded and summed up in the epilogue of the DVH (6–7, pp. 267/268 Friedrich). Healing plants that grew in cold regions are less effective than the plants of hotter regions, since the pores of the latter are looser than the ones of the former and are thus able to absorb to a larger degree the vital air. Consequently, these plants should be picked from hot regions, especially in Egypt, Arabia and Syria.15 A similar view is expressed in the Hermetic treatise De paeonia (CCAG 8.1 188,4–8 ~ CCAG 8.2 167,6–11),16 in which the lunar peony (Paeonia L.) is regarded as particularly potent when picked from the region of Mount Haemus and the mountains of Tauromenium, the Grand Babylon, Thrace, beyond Gadara and the Aegean shores due to the particular astral influences prevailing in these regions.

Nonetheless, in antiquity the abstract concept of sympatheia was interchangeable with that of antipatheia, which distinguishes qualitatively (and not quantitatively) plant lore according to the geographical location in which it grew. This is illustrated with an example given by Asclepius to Thessalos; hemlock (Conium maculatum L.), a plant associated with Mars, is poisonous in Italy, whereas in Crete it is edible (DVH, proem. 29–34, pp. 58/61, 59/62 Friedrich; cf. cod. Vaticanus gr. 1144, f. 243, ed. Boudreaux, 1906: 351–2). An analogous testimony is attributed to pseudo-Democritian lore. Bolus of Mendes in his lost book On Sympathy and Antipathy (in Schol. Nic., Th. 764a, p. 276 Crugnola) mentioned that a deadly plant that grew in Persia, when it was introduced and cultivated in Egypt, produced very sweet fruit due to the benign quality of the Egyptian land.17 Within this concept of antipatheia, the letter’s author incorporates information that draws on the herbal ‘encyclopedia.’ It is the link of hemlock with Crete, based on the conviction that the hemlock that grew in Crete was considered significantly more potent (Dsc., Mat.Med. 4.78.2, p. II 240 Wellmann; Plin., HN 25.154).

Such process of recontextualization of ‘stored’ knowledge is detected in the astrological lore of the letter as well. Asclepius’ revelation to Thessalos conveys knowledge that in other texts is ascribed to the compendium of Nechepsos and Petosiris. The god reveals to Thessalos that seasonal produce grows and withers under stellar influence because the divine spirit (pneuma), which is composed of the smallest particles, pervades all substance, particularly in those places where the stellar influences are the same as the ones prevailing at the beginning of the cosmos (epi tēs kosmikēs katabolēs)18 (DVH, proem. 28, pp. 58/59 Friedrich). In other words, the divine pneuma, equivalent to Stoic nature or god,19 activates all passive matter, especially in regions allotted to the celestial elements of the thema mundi, the nativity of the world (Bouché-Leclercq, 1899: 185–7; Komorowska, 2011). This theory of the chart of the world is also encountered in the example of Asclepius that refers to hemlock, which relies on two astrological theories: namely the system of planetary houses20 and the system of astral geography.21 Hemlock is a plant in sympatheia with Mars and is considered lethal in Italy because Italy is allotted to Scorpio, a zodiacal sign which is the house of Mars. On the contrary, hemlock is edible in Crete because Crete is allotted to Sagittarius, whose ruler, Jupiter, attenuates Mars’ lethal effects (DVH, proem. 29–34, pp. 58/61, 59/62 Friedrich; cf. cod. Vaticanus gr. 1144, f. 243, ed. Boudreaux, 1906: 351–2). The planetary positions of Mars in Scorpio and Jupiter in Sagittarius correspond to the system of planetary houses and at the same time reflect part of the horoscope of the world.

The earliest known astrologers who referred to the thema mundi were Thrasyllus (Epit., CCAG 8.3 100,27–30) (1st cent. CE) and Antiochus of Athens (Isag., CCAG 8.3 118,29–119,10) (1st/2nd? cent. CE). The latter implicitly acknowledges his sources as Nechepsos and Petosiris (= the old <astrologers>), whereas the former probably reflects their theories too, given that his work draws on their writings. For an explicitly expressed ascription we may turn to a later source, the fourth century CE astrologer Firmicus Maternus (Math. 3.1.1, p. II 15 Monat = fr. 25 Riess; 3 proem. 4, p. II 15 Monat = fr. 25 Riess), who remarks that in the thema mundi Nechepsos and Petosiris followed Asclepius and Anubis, to whom Hermes Trismegistus confessed the secret, and handed it down to subsequent generations.22 As regards the system of astral geography, the correspondence of Crete to Sagittarius has been appropriated by authors that predate the letter’s composition and specifically by the first century CE astrologers Manilius (Astron. 4.783–6) and Dorotheus of Sidon (in Heph.Astr., 1.1.160, p. I 21 Pingree; cf. Paul.Al., 2, pp. 6,21, 10,5 Boer). Writers such as Manilius and Dorotheus were only two of the many astrologers, along with Nechepsos and Petosiris, who claimed that their knowledge incorporates a universal truth.

The main corpus of the DVH exhibits similar intertextual links with works communicating a legitimized knowledge.” Some examples will illustrate them. A spell from the London-Leiden Demotic papyrus (col. XI, eds. Griffith and Thompson, 1904: I 80/87 = PDM xiv 309–34) (2nd/3rd cent. CE) preserves instructions for winning favor, which fall within traditional Egyptian ritual practices (Quack, 2011: 68–70). A wax figurine of a baboon (the sacred animal of Thoth) is anointed with oil and other ingredients and is placed in a faience vessel. Then, a wreath is also anointed and an extensive spell is uttered seven times before the Sun at dawn. The practitioner will gain favor and praise after smearing his face with the foregoing ointment and placing the wreath in his hand. The ritual ends with the assurance that this scribe’s feat is that of a king whose name unfortunately has not been preserved in the papyrus, except for the final sign š. The papyrus’ editors (Griffith and Thompson, 1904: I 86, n. l.26) suggested that the king in question was Darius I. However, Ryholt (2011: 62; see also Quack, 2011: 68–9) argues that the orthography of the Demotic name Nechepsos (Ny-kȝ.w pȝ šš) corresponds better to the Egyptian tradition.23 In light of this argument, a close link between the papyrus London-Leiden and the DVH is drawn. Similarly, according to the DVH (2.1.4, p. 199 Friedrich), the juice of chicory (alias heliotrope),24 a plant associated with the Sun, confers favor if the petitioner, while facing the sunrise, anoints his face with it and summons the Sun god Helios begging him to provide grace. An analogous recipe is displayed in the Hygromantia Salomonis, a late antique Hermetic text (CCAG 8.2 164,1–4; cf. CCAG 12 130,21–3 ~ Delatte, 1949: 169,9–11); the leaves of the Sun’s plant sun-spurge (Euphorbia helioscopia L.), when pounded and mixed with rose extract, are anointed on the face, thus currying favor. Much closer to the first two formulas is the one found in the first and most ancient book of the Kyranides (1.22,7–15, p. 101 Kaimakis); the stamen and flower of chrysanthemum, here identified most probably with immortelle (Helichrysum L.), mixed with rose oil and spread on the eyes, bring favor, attractiveness and the ability to make friends easily, especially when the ritual is practiced at sunrise.25

The Kyranides provide further insights into the ways in which the DVH contextualizes a malleable body of knowledge. The formula that the root of peony expels demons when fumigated is appropriated by both the DVH (2.2.3, p. 207 Friedrich) and the Kyranides (1.3,21–2, p. 36 Kaimakis), texts where peony is addressed by the name aglaophōtis and glykisidē respectively, as well as by the treatise De paeonia (CCAG 8.1 191,11–3 ~ CCAG 8.2 170,1–2; cf. CCAG 12 118,23–6; Thomson, 1955: 83,13–4). Fennel (Foeniculum vulgare Mill.), as described in the DVH (1.11.4, pp. 167/171 Friedrich), is taken to be identical with the plant edder-wort (Arum dracunculus L.) and its juice is beneficial to the eyes when used as a lotion. The seed of edder-wort yields the same effect when worn as an amulet in the Kyranides (1.4,24–5, 66–9, pp. 40, 42 Kaimakis). Other examples of the intertextual analogies between the DVH and the late antique Hermetic literature include holy vervain (Verbena officinalis L.) as a cure for the callous lumps and the diseases of the mouth and tonsils (DVH 1.3.2, pp. 93/94 Friedrich; CCAG 7 233,17–20 ~ CCAG 8.3 161,30–3; cf. CCAG 9.2 134,8–10) and birthwort (Aristolochia L.), which is used as a medicine for eye diseases (DVH 1.12.3, 6, pp. 175, 179 Friedrich; CCAG 8.2 162,13–4).

Certain prescriptions of the DVH are also encountered in Pliny’s Historia Naturalis, in which they are ascribed not to Asclepius or to Hermes but to the Persian Magi. Pliny (HN 20.74, 22.61), drawing on the magian rhizotomic tradition, reports that the juice of chicory mixed with oil and anointed on the body curries favor and praise, and that when worn as an amulet the heliotrope is therapeutic for tertian and quartan fevers. These similarities notwithstanding, in the DVH (2.1.2–3, p. 199 Friedrich) chicory, alias heliotrope, cures tertian and quartan fevers when applied as an ointment but not when carried as an amulet (Nechepsos’ solar lozenge had an identical application for the treatment of fevers, as has already been mentioned above). In his lost work Cheirokmēta (in Plin., HN 24.160), Pseudo-Democritus notes that the Magi use aglaophōtis to summon the gods and that the plant grows among the marble mines of Arabia (on the Persian side), the same region where peony predominantly grows according to the DVH (2.2.1, p. 207 Friedrich). Pliny contrasts the magian rhizotomic tradition with his own elitist understandings of herbal healing methods and efficacy, acknowledging the latter to be far superior to the former (Janowitz, 2013; cf. Gordon, 1987: 74–8; idem, 1999: 229–31). Nevertheless, when integrated in the DVH this body of knowledge is transposed into a different synthesis that is ascribed to different authorities with contrasting implications. The DVH is a work that lists the marvelous efficacies of the healing astral plants as a revealed knowledge of no less an authority than Asclepius or Hermes Trismegistus.

Almost all of the above recipes exhibit continuities with, and resystematization of, an already formulated intertextual and rhizotomic ‘encyclopedia.’ Dioscorides (Mat.Med. 3.140.3, p. II 150 Wellmann ~ CCAG 11.2 165,28–30; cf. Dsc., Eup. 1.22, pp. III 161–2 Wellmann) remarks that when chewed and swallowed with wine or with a mixture of honey and water, peony’s black grains relieve those tormented by throttling demons (ephialtes = personified nightmares; see also peony as ephialtia in Aët., 1.84, p. I 50 Olivieri).26 This prescription is restated by Pliny (HN 25.29, 27.87), who writes that peony is a suitable cure for the nightmares that the goatish demon-gods, the Fauni, bring during sleep; it particularly wards off nightmares when its black seeds are taken with wine. Moreover, edder-wort and fennel were widely considered cures for eye diseases (edder-wort: Dsc., Mat.Med. 2.166.4, p. I 233 Wellmann; idem, Eup. 1.41.3, p. III 165 Wellmann; Plin., HN 24.144, 146; Gal., Simpl.Med. 6.4.9, p. XI 865 Kühn; fennel: Dsc., Mat.Med. 3.70.2, p. II 81 Wellmann; idem, Eup. 1.41.2, p. III 165 Wellmann; Plin., HN 20.254, 29.119; Gal., Simpl.Med. 7.12.5, pp. XII 67–8 Kühn; Schol. Nic., Th. 33b, p. 48 Crugnola), holy vervain was regarded as a treatment for mouth ulcers (Dsc., Mat.Med. 4.60.2, p. II 215 Wellmann; Archig. in Aët., 1.318, p. I 120 Olivieri) and for problems of the tonsils and throat (Dsc., Mat.Med. 4.60.2, p. II 215 Wellmann; Plin., HN 30.35), and heliotropes were recommended as remedies for tertian and quartan fevers (Dsc., Mat.Med. 4.190.2, p. II 339 Wellmann; idem, Eup. 2.20.2, 2.21.1, p. III 248 Wellmann; Plin., HN 22.60).27 Birthwort is the only medicinal plant exempted from this intertextual rhizotomic corpus, taking into account that its properties for curing eye diseases are only attested by Pliny’s Historia Naturalis (25.143).

While plants’ medicinal properties had been noted by ancient scholars, it is mostly their peculiar characteristics that led to their incorporation within miraculous herbalism. The observation that the heliotropes and the sun-spurge follow the Sun in its yearly or daily route (heliotrope: Nic., Th. 678–80, p. II 53 Jacques & Schol. Nic., Th. 676d, 678a, p. 251 Crugnola; Dsc., Mat.Med. 4.190.1, p. II 338 Wellmann; Plin., HN 2.109, 18.252, 22.57; Plut., in Hes., fr. 101 Sandbach; cf. Thphr., HP 7.15.1; sun-spurge: Dsc., Mat.Med. 4.164.7, p. II 313 Wellmann; Plin., HN 26.69) and that the flower and leaves of immortelle are of golden color28 (Thphr., HP 9.19.3; Theoc., 2.78; Dsc., Mat.Med. 4.57, p. II 211 Wellmann; Plin., HN 21.66, 168; Kyr. 1.22,7, p. 101 Kaimakis) determined their association with the Sun. Thus, a particular taxonomy led to the reintegration of these specific plants into discourses that embodied ritual practices in which the Sun god Helios played a certain role (Quack, 2011: 73–4; cf. Faraone, 1999: 139–41). Once the heliotropes were in sympatheia with the Sun, they were thought to encompass the star’s fiery character and they were regarded as plants allegedly able to cure diseases characterized by the element of fire.

On the other hand, peony was a plant that should be dug up only during the night-time and it was considered dangerous but useful (Thphr., HP 9.8.6; Plin., HN 25.29, 27.85; cf. Ael., NA 14.27), two perceptual anomalies that marked peony’s marvelous properties, credited with the ability to expel demons or to summon the gods (cf. Gordon, 1987: 84–5). Presumably, these virtues were conceptually entwined with the lunar physiognomy of peony, whose affinity with the Moon (based on its healing properties) occurs in the DVH, as well as in the text De paeonia.

Edder-wort was associated with snakes due to the peculiar shape of its stem which resembled serpents (Thphr., HP 9.20.3; Dsc., Mat.Med. 2.166.1, p. I 231 Wellmann)—a characteristic feature indicated by its Greek name itself, drakontion, which is the diminutive of the noun for ‘serpent’ (LSJ s.v. δράκων, I). Since the Greek word drakōn originates from a verb that conveys the sense of ‘see clearly’ (LSJ s.v. δέρκοµαι, I.1), signifying a link of snakes with eyes/vision (Bodson, 1981: 65), edder-wort was included in ancient herbal taxonomies as a remedy for eye problems. In addition, the popular belief that snakes, after their hibernation, taste the fennel or rub themselves against it to improve their eyesight (Nic., Th. 31–4, p. II 4 Jacques & Schol. Nic., Th. 33b, p. 48 Crugnola; Plin., HN 8.99, 20.254; Plut., Sol.Anim. 974B; Ael., NA 9.16)29 attributed similar properties to this plant. This correlation of edder-wort and fennel with snakes meant that these plants were assigned to the sign of Aquarius in the DVH since Aquarius is the house of Saturn, with which snakes were associated (Ducourthial, 2003: 461; Pérez Jiménez, 2010: 216, 217).

For the rest of the cases, the plants’ symbolic values continue to shape the way they are appropriated by Hermetic astrologers, even though their properties, as listed above, seem not to be dictated by any semantic causality. Vervain was chosen on account of its Greek name peristereōn, which is derived from the noun for the ‘pigeon’ (LSJ s.v. περιστερά). Pigeons were the sacred birds of Aphrodite and therefore vervain developed an analogical relationship with Aphrodite’s planet, Venus (Ducourthial, 2003: 346, 396; Pérez Jiménez, 2010: 227).30 With regard to birthwort, its double species, female and male, as described in Nicander’s Theriaka (514–6, p. II 42 Jacques & Schol. Nic., Th. 509a, p. 200 Crugnola) and in the DVH (1.12.2, p. 175 Friedrich), determined the plant’s correspondence to the analogous ‘double’ sign of Pisces in the Hermetic texts (Ducourthial, 2003: 468).

Once different traditions are fixed in textual units, the textual material is reinvested with a specific cultural meaning, dependent on the authority invoked and the associations evoked. To the extent that the content of the DVH was compiled mostly from borrowed material, the author of the letter aims to create a rift with tradition. As a result, Nechepsos is made to stand for an embodiment of received knowledge. Even though Thessalos characterizes Nechepsos as a royal folly (DVH, proem. 6, p. 47 Friedrich = fr. 35 Riess), the god Asclepius reveals to him that the king was of an extremely sound mind and gifted with all virtues, managing to perceive the astral sympatheia of stones and plants owing to his own good nature. Yet, because he lacked the divine wisdom to know the exact time and place for picking each plant, he was incapable of bringing his project to fulfillment (DVH, proem. 27, pp. 55/58, 56/59 Friedrich = frs. 35, 36a Riess). Hence, Thessalos’ text aims at supplementing Nechepsos’ manual and particularly at providing information about the exact time and place of plant collection, rather than refuting his authority (Fowden, 1993: 164; Gordon, 1997b: 77; Harland, 2011: 133; Moyer, 2011: 229–30; contra Smith, 1978: 177; cf. Ní Mheallaigh, 2014). Soon after, the incomplete book of Nechepsos was replaced by the divine book of Thessalos, who brought papyrus and ink with him to the place of the revelation in order to write down Asclepius’ words and to create the work for which his letter is the foreword (DVH, proem. 21, p. 53 Friedrich). Consequently, the knowledge of the Egyptian astrologer is invested with claims of reworking and updating within the letter itself.

Thessalos’ narrative further stresses its authoritative status through its underlying opposition concerning the particular locations with which the manual of Nechepsos, as well as his own book, were linked, since space (whether it is religious or not) is not devoid of meaning; it is, rather, socially represented and invested with cultural memories (Alcock, 2001; Bommas, 2012). Nechepsos’ book was found in a library of Alexandria in Lower Egypt, while Thessalos’ book was recorded within a temple located in Upper Egypt, in Thebes.31 The significance of these two locations (library and temple) is played off against the ways in which Alexandria and Thebes are conceptualized through their symbolic and imaginary representations. The Greeks, first as colonists and later as conquerors, having settled mainly in the Nile Delta and in the area of Faiyum in Lower Egypt, had not developed particular trade networks with the Egyptian mainland and Upper Egypt. The Hellenization that occurred as a consequence of the urbanization in the North is contrasted to the stronger native Egyptian element of the Theban area, which is considered to embrace the true wisdom of Egypt compared with the Hellenized Alexandria (Moyer, 2003: 45–6; idem, 2011: 249–53; cf. Klotz, 2012). As a city and symbol of Hellenization, and later of Romanization, Alexandria is turned by Thessalos into the symbol of the inadequate knowledge of Greeks and Romans alike in contrast to the divine ‘Egyptian’ wisdom of Thebes.

The rhetoric the author employs to construct his discourse is shaped by the intellectual culture and the agonistic context of the era, and is further amplified by the excess production and oversupply of texts. In doing so, he is implicated in the polemics and self-promotion that often permeate various works of Graeco-Roman antiquity in which the author criticizes and departs from received tradition (cf. Lloyd, 1987: 50–108). The use of pre-existing astrological lore by an author like Thessalos, coupled with the claim that he supplements a previous work, is a topos in Graeco-Roman astrological treatises as well as being a useful rhetorical device. It enables astrologers to invent new astrological theories and develop up-to-date theoretical analyses in a competitive display of their art, drawing at the same time on the authoritative foundations of their discipline. Vettius Valens (1.22.16, p. 53 Pingree; 2.37.1, p. 103 Pingree; 3.11.1, p. 146 Pingree = fr. 19 Riess; 6.1.17–9, p. 232 Pingree; 6.8.16, pp. 247–8 Pingree), for instance, presents himself as aiming to elucidate several astrological topics which, as he claims, are treated also by the ancients,32 but in secret and obscure ways.33 In his seventh book (7.4.1, p. 260 Pingree), he escalates his rhetoric, wondering whether the ancients, motivated by their envy, concealed their activity of forecasting because of their boastfulness and the difficulty of their art or whether they wrote in an obscure manner because they did not comprehend the secrets of nature.

In several cases Nechepsos, together with Petosiris, form an integral part of this rhetoric.34 Valens (8.5.19–20, p. 288 Pingree) attests that Nechepsos and Petosiris showed that their discipline lacked any foundation because they represented their profession in a dull and abstruse manner. He notes that neither Petosiris nor Nechepsos extensively dealt with the system of the ‘place of travel’ in nativities (2.29.1–2, p. 91 Pingree), while he presents Nechepsos as having wisely admitted to, and amended, the early mistakes he had made (9.1.3, p. 316 Pingree).35 Devoid of any institutional backing, the discipline of astrology legitimated itself by using various rhetorical modes drawn from a vast arsenal of persuasion (Riley, 1987: 250–4; Barton, 1994a: 134–42; eadem, 1994b: 82–90; Gordon, 1997a: 143–6). Rhetorical contest and dispute, didactic devices, theoretical complexities or innovations, and the propensity of inquiry transformed the legendary king’s book into an astrological source bound to be supplemented, or even superseded, by subsequent astrologers.

Thessalos incorporates these tropes into pre-existing narratives. According to two unpublished Demotic papyri from the Tebtunis temple library (P.CtYBR 422^v and P.Lund 2058^v) (1st/2nd cent. CE), the sage Petesis (= Petosiris)36 deciphered and presented to pharaoh Nechepsos an astrological papyrus of Imhotep which was discovered when part of a wall at the temple of Heliopolis collapsed (Ryholt, 2011: 62; Moyer, 2011: 245–6; see also Ryholt, 2006: 2, 3, 13–6; idem, 2009: 313, n. 30).37 A horoscope for December 4, 137 CE, preserved in P.Louvre 2342^bis = P.Paris 19^bis (col. I 2–6, eds. Neugebauer and Van Hoesen, 1959: 42 = test. 6 Riess), presents Hermes and Asclepius/Imouthes as instructing both Petosiris and the king Necheus (= Nechepsos). Likewise, Firmicus Maternus (Math. 3.1.1, p. II 15 Monat = fr. 25 Riess; 4 proem. 5, p. II 127 Monat = test. 7 Riess) considers Nechepsos and Petosiris to be followers of Asclepius or interpreters of his teachings. This tradition is modified by Thessalos, who replaces Nechepsos with himself and updates the king’s manual in order to highlight the inadequacy of the knowledge of Alexandria and the Empire in favor of the divine wisdom of Thebes and Egypt. In other words, such discourse attempts to claim continuity with authentic Egyptian tradition as a means of defending a positive image of Egypt against Graeco-Roman perceptions concerning the worthlessness of Egyptian civilization (Gordon, 1997b: 76–7).

The sophisticated scribal practices of Hellenistic and Roman times invoke a dynamic aspect of the notion of ‘tradition.’ Tradition is what appears, in the first place, to be a set of knowledge systems inherently fixed as they are transmitted through the written record. Yet, over time written tradition changes: a change that is not completely noticed by those who participate in it on account of its construction by particular rhetorical modes that aim at pointing out their continuity with a presumed ‘authentic past.’ A legitimization conferred by the appropriation of commonly ‘accepted’ knowledge was a possible option when someone, such as Thessalos, was about to create a new text on the subjects of astrology and ‘magic’ (the latter term employed by Thessalos himself). In several cases, however, such reliance upon tradition could be harmful to one’s reputation, especially in an era of intense competition, egotism and novelty. A solution to this literary problem is to use what has been handed down from the past, but to recast its invested authorities.

Thessalos’ text is a case in point of this method. In a previous study (Piperakis, 2014: 85–7), I suggested that the letter and the epilogue of the DVH were composed by Thessalos for the sake of framing two originally independent (Hermetic?) herbal manuals, which constitute the two sections of the zodiacal and planetary pharmacopoeia of the DVH, into one cohesive block of textual data. Thessalos incorporates into his letter elements of Nechepsos’ lore and of the rhizotomic and astrological expertise of his times and he also collects and preserves in a converted format the textual material of the two manuals that were drawing upon pre-existing knowledge systems. The limited space of this article does not allow me to discuss this profound dependence in significant detail, but only to provide some examples. Yet, elsewhere (Piperakis, 2014: 69–70, 258–61), I have already indicated that most of the nineteen plant properties have an intrinsic tautology with the ones attested in previous works. What Thessalos aims to do with his narrative is to recast a new identity, a new meaning, to the malleable and common cultural property from which his own writings and the two manuals derive. By replacing the manual of the famous astrologer Nechepsos with the divine revelation of Asclepius/Imhotep that occurred in Upper Egypt, he contextualized his textual corpus as an original commodity of the truly magico-divine Egyptian wisdom and as a means of intellectual response to Roman hegemony. Enshrined in a specific didactic discourse and addressed to the Roman emperor, this corpus is exported to the Graeco-Roman oecumene, to a clientele craving the ancient wisdom of Egypt.

CCAG = F, Cumont et al. (Εds.) 1898–1953 Catalogus Codicum Astrologorum Graecorum. 12 vols. (in 20 parts). Brussels: Lamertin/Aedes Academiarum; LSJ = H G, Liddell and R, Scott (Eds.) 1940 A Greek-English Lexicon (rev. by H S, Jones & R, McKenzie, with a rev. supplement of 1996). 9th ed. Oxford: Clarendon Press; PDM = H D, Betz (Ed.) 1986 The Greek Magical Papyri in Translation, Including the Demotic Spells. Chicago, IL/London: University of Chicago Press; PGM = K, Preisendanz 1973–4 Papyri Graecae Magicae. Die griechischen Zauberpapyri. 2 vols. 2nd ed., Ed. A, Henrichs. Stuttgart: Teubner. The full form of abbreviations used in referring to the rest of the papyri can be consulted from their editions quoted next to them.

The author declares that they have no competing interests.