After listing various arguments pro and con as to whether the via experiment “is of art and in art, or precedes art,” Peter gives his solution to the effect that experimentum is threefold. As a method of attaining knowledge it antecedes all arts and sciences. As a method of making known the objects of scientific inquiry, it is a part of science. As an application of scientific doctrine to practical life and industry, it follows science. Furthermore, experience “may proceed regularly through science and doctrine and in this way it can be rational.” Or it may be irregular and not syllogistic in method. The experimental discoveries of brutes, as when the serpent restores its sight with fennel, come to them from nature, but ours are acquired by art and confirmed by reason, although man too possesses the experimental instinct. Peter further distinguishes the experiences of rustics, which are unregulated by reason, from the experiments of skilled men which are regulated by reason. Moreover, “experiences are not without their reasons, and idle is the experiment which does not rest on reason.” Finally, Peter gives six conditions requisite in medical experimentation which are somewhat similar to the seven conditions stated by his contemporary, John of St. Amand. First, the medicine administered should be free from all foreign substance.[1681] Second, the patient taking it should have the disease for which it is especially intended. Third, it should be given alone without admixture of other medicine. Fourth, it should be of the opposite degree to the disease. Fifth, “we should test it not once only but many times.” Sixth, “the experiments should be with the proper body, as on the body of a man and not of an ass.”
Peter’s discussion of the via experimenti is in several respects similar to Roger Bacon’s discussion of experimental science, but is probably quite independent of it. Peter died before Roger in 1277, and his Commentary on Isaac was probably composed before the works which Bacon addressed to the pope in and around the year 1267. The influence of Galen, who had discussed the part played by reason and experience in his own work on food values, upon Peter is fairly evident.
John of St. Amand, to whose similar conditions for medical experimentation we just alluded, was a canon of Tournai who seems to have written a little later than Peter, since he describes the death from vomiting of a bishop of Tournai which took place in 1261.[1682] It is in his commentary on the Antidotarium of Nicolaus that John gives his seven conditions for medical experimentation. After having said that on account of the scarcity and incompleteness of experience, we should sometimes learn the virtues of simple medicines “through doctrine,” John for a page or two discusses other matters, but then reverts to the subject of experimentation. A medicinal simple, he says, may be known by two methods, “the way of experience and the way of reason.” “And because the principles of experience are better known to us than the principles of reason, let us first inquire concerning the knowledge of medicinal simples by the way of experience.” He goes on to say that experience is twofold as it is supported or not supported by reason. If unsupported by reason experience or experiment is timorous and fallacious. As for experience supported by reason, it should conform to these seven requirements.[1683] First, “the medicinal simple which is being tested should be pure and free from every extraneous quality, lest by such extraneous quality the proper operation of the medicine be impeded, and in consequence experimental knowledge.”[1684] Here the use of the adjective, “experimental” is interesting. Second, the experimentation should be with a simple and not a complicated disease.[1685] Third, the simple should be tested in two contrary types of disease, because sometimes a medicine cures one disease by its “complexion” or elemental properties and another by its occult virtue. Thus scammony cures both quotidian and tertian fever; the first because scammony is of a hot nature; but the second by its occult virtue and not because scammony is of a cold nature, for it is not.[1686] Fourth, the virtue of the medicine should correspond to the quality of the patient. Fifth, essence and accident should not be confused; water, for example, may be heated, but is not of a hot nature.[1687] Sixth, the experiment should be often repeated. For if a medicine is tested in the cases of five men and has a heating effect upon them all, still that is not adequate proof that it will always have a heating effect, for they may have all been of a cold or temperate constitution, whereas a man of hot nature would not be heated by the simple in question. Seventh, the test should be on the human body and in varying states of health. Trying the medicine upon a lion may not prove anything as to its effect upon a man.[1688] John seems to have taken his conditions directly from Galen rather than from Petrus Hispanus, since only three of them are identical with Peter’s, whereas all but one occur in his own Concordances from Galen’s works.[1689] John of St. Amand repeats the experiment with the hazel rod which we have already encountered in William of Auvergne. According to John the two split halves tend to reunite because it is natural for them to be together, but he adds that some old women make use of it with utterance of a useless incantation as a matrimonial charm, asserting that if the halves unite, the marriage will be a happy one.[1690]
It was not my intention to speak of John of St. Amand further than to compare his remarks on experimental method with those of Petrus Hispanus, but the Histoire Littéraire has already presented some specimens of his views, which it will be worth repeating to show that his experimental tendency has the same accompaniment of mingled credulity and scepticism and of occult science and signs of magic as we have noted in other cases. Thus he rejects the story that the beaver castrates itself to escape the pursuit of hunters on the ground that the animal has not that much sense, but believes that beavers enslave one another. From the fact that herons are subject to diarrhoea he argues that men with long necks and legs should not resort to purgatives, and he states that pearls comfort the heart by similarity, since they are hard like the heart. He enters into long and obscure explanations how it is that application of the flesh of a snake extracts the venom from its bite, and “is not exempt from astrological ideas.”[1691] But the writings of John of St. Amand have carried us well along into the second half of the thirteenth century; in the next chapter we must turn back to a man whose literary activity began in the Erst half of that century, Albertus Magnus.
[1614] Ptolemaei Lucensis Historia Ecclesiastica. Liber XXIII, cap. xxi, in Muratori, XI, 1176. For the life of John XXI see also HL XIX (1838) 322-34; J. T. Koehler, Vollständige Nachricht von Pabst Johann XXI, Göttingen, 1760; L. Zdekauer, in Bullettino Senese di Storia Patria, VI (1898-1899); Richard Stapper, Papst Johannes XXI, Münster, 1898, in Kirchengesch. Studien herausg. v. Dr. Knöpfler, Band IV, Heft iv.
[1615] Millot-Carpentier (1901). G. Porro, in his catalogue of Trivulzian MSS at Milan, Turin, 1884, calls Peter “Petrus Julianus Ulissiponensis.”
[1616] Royal 13-A-VII, 15th century, fol. 149r.
[1617] Stapper (1898), p. 4, “In illis namque laribus ab annis teneris diutius observati variis scientiis inibi studiose vacavimus et per annos plurimos....”
[1618] See too, C. von Prantl, Michael Psellus und Petrus Hispanus, 1867.
[1619] HL XIX, 330.
[1620] Harleian 5218, fols. 1r-3r, Epistola Magistri Petri Hyspani missa ad Imperatorem Fridericum super regimen sanitatis. It seems strange, however, that Peter should call himself, as he does in this work, “senex artis medicinae professor,” before 1250, when he would have been rather less than forty years of age. Other MSS. are: CLM 615, 13-14th century, fols. 41-68; BN 7446, 15th century.
[1621] “Hic generalis clericus fuit et praecipue in medicinis.”
[1622] HL XIX, 327-8; namely, the Thesaurus pauperum, and the commentaries on Isaac on Diets and Urines.
[1623] Sloane 1214, 15th century, fols. 38r-46, De morbis oculorum. Other MSS of his work or works on eye diseases are: Sloane 2268, 14th century, fols. 52-59; CLM 161, 13th century, fols. 55v-57, de aegritudinibus oculorum; CLM 40, 14th century, fols. 112-15, Breviarium de aegritudinibus oculorum; CLM 381, 14th century, fol. 78-, Curae ... de passionibus oculorum, vel Secretum pro amico ad oculos; CLM 438, 14th century, fol. 108, de passionibus oculorum; Wolfenbüttel, 2794, 15th century, fols. 183-8, Petri Hispani liber oculorum, fol. 188v, Secretum magistri Petri Hispani; BN 6957, 15th century, #1, Secretum de oculis.
[1624] Cholmeley, John of Gaddesden, 1912, p. 183, says that Peter had been Gregory’s physician.
[1625] Millot-Carpentier (1900), p. 180.
[1626] Printed at Antwerp in 1476 and 1497, at Lyons in 1525, at Frankfurt perhaps in 1567, 1575, 1576, and certainly in 1578, at Paris in 1577. I have used the 1497 edition,—Summa Experimentorum sive thesaurus pauperum magistri Petri yspani, Antwerpiae, Theodoricus Martini, 1497 (die 22 Mai). A letter lying loose in the copy (numbered IB. 50018) which I read at the British Museum, stated that the copy at Liège is (was) the same. I also consulted the edition printed at Frankfurt in 1578 but it seemed faulty compared with the 1497 edition. For a list of MSS see Appendix I at the close of this chapter.
[1627] Stapper (1898), p. 23.
[1628] Sloane 284, Harleian 5218, Additional 25,000 contain the sentence; Sloane 521 and 2479, and Royal 12 B III do not have it. The entire preface is missing in Addit. 22,636 and in the early MS, Sloane 477, but it also has no Incipit and a first sheet may well be missing which contained the preface.
[1629] The sentence as Stapper gives it (p. 24), reads: “Litteras autem quas aliquando ponunt physici superstitiose positas nemo credat, sed quia immediatius operantur vel magis assidue, sicut dextrum dextro vel sinistrum sinistro membro et masculo apponitur.” In the 1497 edition and Sloane 284 the sentence reads more correctly: “Ligaturas autem quas aliquando posuerunt philosophi nemo credat superstitiose positas, sed immo quod (ideo quia) immediatius operantur vel magis assidue si (vel aliter) numquam deponuntur vel a simili sicut si ad (aliud) dextrum dextro membro vel sinistrum sinistro vel masculinum masculino apponatur.” In the 1578 edition the sentence has been completely changed and begins: “Characteres vero et de collo suspendenda quorum interdum a Philosophis sit mentio nemo arbitretur superstitiose tradita esse sed ideo quia immediate operantur vel magis per ἀντιπάθειαν ...” etc.
[1630] For instance, among remedies for sore throat an herb “divinely revealed to good bishop Boniface” and “a good prayer” were detailed in the 1497 edition, but I failed to find them in Sloane 477, Sloane 2479, Additional 32,622, or Royal 12-B-III. The next remedy after the good prayer was given in Sloane 477 only in the margin, but in Additional 32,622 appeared in the body of the text. In the chapter on toothache, too, a remedy written in the margin in a different ink from the text of Sloane 477 is embodied in the text of Sloane 521 and 2479 as well as in the 1497 edition.
[1631] Gilbert of England’s Compendium adopted essentially that order.
[1632] See also CLM 457, 15th century, fol. 112-, De febribus. Sunt aliqua capitula ex thesauro pauperum Hispani Petri.
[1633] Sloane 521 and Addit. 32,622 omit “occult.”
[1634] Even in an early MS like Sloane 477 we find the first person used a great deal and experience or “experiments” often mentioned.
[1635] Sloane 2479, fol. 37v, fol. 14r, fol. 13v; and in other MSS.
[1636] These remedies for toothache will all be found in Sloane 477 and 2479, Addit. 32,622, and Royal 12-B-III, as well as in the 1497 edition.
[1637] 28, 49 and 30, 8.
[1638] Sloane 477, fol. 9r.
[1639] Sloane 2479, fol. 14v; Addit. 25,000, fol. 79v; Addit. 32,622, under the heading “De spasmo.”
[1640] Sloane 477, fol. 10r does not cite Constantine and Walter, but other MSS do.
[1641] Sloane 2479, fol. 14v; Royal 12-B-III, fol. 19v; Addit. 25,000, fol. 79v; Harleian 5218.
[1642] All the items mentioned in this paragraph are found in the early MS Sloane 477 as well as in other MSS. In a fifteenth century MS at Florence (Ashburnham 143, fols. 113-14), this chapter appears separately as, “Capitulum pulcrum pro maleficiis malis” and under the further sub-titles, “De hiis qui maleficiis impediti cum uxoribus cohire non possunt. Pro maleficiis destruendis secundum magistrum Petrum Yspanum.”
[1643] For the De morbis oculorum I have used two MSS. in the British Museum; Sloane 1214, 15th century, fols. 38-46, and Sloane 2268, 14th century, fols. 52-59. I presume that Gonville and Caius 379, 13th century, fols. 142-49, “Secreta mag. Petri yspani ad oculos. In nomine summi opificii/acceptis de pectine matris,” is the same work.
[1644] Sloane 1214, fol. 38r; Sloane 2268, fol. 52.
[1645] Sloane 2268, fol. 54v.
[1646] Op. cit. (1901).
[1647] Sloane 1214, fol. 38r.
[1648] Sloane 2268, fol. 54v. Millot-Carpentier presumably has this passage in mind when he says, “Il connaissait la fistule lacrymale qu’il soignait ... par les exorcisms.”
[1649] Royal MS. 13-A-VII, 15th century, fols. 149r-153v. “Explicit summa magistri p. de conservanda sanitate et de his quae conferunt et nocent. Finito libro reddetur gratia Christo amen. Rogatis deum pro anima magistro qui hunc librum composuit. Explicit liber.” See also CLM 14574, 15th century, fol. 117. Magistri Petri liber de conservanda sanitate, “Erubescant Judei confundantur Sarraceni.”
[1650] Cap. 1, fols. 150r-v.
[1651] Sloane 2268, 14th century, fol. 52-, De morbis oculorum; fol. 56r, “Tractatus mirabilis aquarum quod composuit m. p. hyspanus cum naturali industria secundum intellectum”; fol. 59r, “Explicit secretum magistri P. hys. quod fecit pro amico suo ad oculos.”
BN 6957, 15th century, #2, Tractatus mirabilis aquarum quem composuit Petrus Hispanus cum naturali industria secundum intellectum. Explicit secretum magistri Petri Hispani de oculis, (as described by Renzi, V, 122).
BN 7349, 15th century, #2, is the same treatise.
[1652] Additional 32,622, early 14th century, fol. 95r, “Actus mirabilis aquarum quas composuit Petrus Hispanus cum naturali industria.”
Egerton 2852, 14th century, fols. 1-5, “de aquis,” is very similar in contents to Addit. 32622.
[1653] Digby 147, 14th century, fols. 104r-105v, “Tractatus mirabilis aquarum quem composuit philosophus naturali industria secundum intellectum.” It opens, “Aqua mirabilis valet ad visum conservandum.”
[1654] Namely: 1 aqua mirabilis ad visum conservandum et clarificandum, 2 aqua preciosa de radicibus, 3 aqua preciosa de seminibus, 4 aqua mirabilis per quam facit mistica sive mirabilia medicus, 5 aqua salicis, 6 aqua aromatica, 7 aqua qui dicitur lac virginis, 8 aqua tartari, 9 aqua de sale gemme, 10 aqua copose, 11 aqua vite, 12 aqua ardens.
[1655] See below, pp. 797-8.
[1656] I regret that I have not been able to examine and compare this and the other MSS of the treatise more closely in order to ascertain how far their texts are identical or vary. Some further MSS are:
CU Trinity 1411, early 16th century, fol. 131, Aqua mirabilis Petri Hispani.
Harleian 1887, 16th century (?), Petrus Hispanus, mirab. aquar.
[1657] Assisi 292, 15th century, 75 fols.
[1658] BN 7446, 15th century, Regimen sanitatis.
[1659] Harleian 2258, fols. 224v-225v, regimen salutis per omnes menses.
[1660] Bibl. Palat. Parma 1065, 15th century, fols. 147-53.
[1661] Corpus Christi 243, 1423 A. D., fols. 15v-28, “Sicut igitur in negotio nostro de anima ... / ... Explicit liber de morte et vita et de causis longitudinis ac brevitate vite magistri Petri Hispani.”
[1662] Sloane 568, late 14th century, fol. 15v.
[1663] BN 6956, 14th century.
[1664] Vienna 4751, 15th century, fols. 274-80, excerptus et in fine mutilus.
[1665] Printed in the Lyons, 1515 edition of Isaac’s works: fol. xir, Commentarium singulare doctissimi viri Petri hispani olim pontificis maximi Johannis vicesimiprimi super librum dietarum universalium Isaac Incipit; fol. ciii, Apollinee artis monarche Ysaac filii adoptivi Salomonis regis Arabum diete particulares cum uberrimis excellentissimi viri Petri hispani commentariis.
[1666] Ibid., fol. 12r.
[1667] Ibid., fol. 14v.
[1668] “An caro coda in pasta sit bona?” Peter thinks that it is pessima, because the pastry prevents the noxious fumes and humors of the meat from escaping, but he adds, “Contrarium facit vulgus.”
[1669] An interesting passage, which seems to indicate that despite frequent famines the medieval poor were seldom reduced to horse meat. Peter’s explanation is that these animals are not poisonous, but that nature designed them for man’s service, not his nutriment.
[1670] On this point Peter does not seem to be in agreement with some modern sociologists.
[1671] Peter of course answers in the negative.
[1672] fol. 145v.
[1673] fol. 78.
[1674] fol. 150v.
[1675] fol. 103r.
[1676] fol. 149r; fols. 150v-151r.
[1677] fol. 127r.
[1678] fol. 136r.
[1679] fol. 135v, and De animal. hist. ed. Dittmeyer (1907), p. 362, lines 29-30. λέγεταιδ’ ὡς ἀριστερὸν κέρας οὐδείς πω ἑώρακεν ἀποκρύπτειν γὰρ αὐτὸ ὡς ἔχον τινὰ φαρμακίαν. The last word, of course, suggests either a drug or poison, medicine or charm.
[1680] fols. 19v-20v; see also fol. 11v.
[1681] “... medicina sit tuta ab omni qualitate complexionali.”
[1682] On Jean de Saint-Amand see HL XXI, 254-66; J. L. Pagel, Die Concordanciae des Johannes de Sancto Amando, Berlin, 1894, and Nachträge zu den Concordanciae des Johannes de Sancto Amando, Berlin, 1896. For the Expositio in Antidotarium Nicolai, I have followed the text in Mesuae medici clarissimi opera, Venice, 1568; but there are earlier editions, such as Venice, 1497, and Lyons, 1533.
[1683] Expositio in Antidotarium Nicolai (1568), fol. 231, “Sed medicina simplex duplici via cognoscitur scilicet via experimenti et via rationis.... Et quia principia experimenti sunt nobis magis nota quam principia rationis, ideo prius inquiramus cognitionem simplicium medicinarum via experimenti ... duplex est experimentum ... vallatum et non vallatum ratione, tunc ipsum est timorosum et fallax si non sit vallatum ratione....”
[1684] Ibid., “Oportet ut medicina simplex quae experiatur sit pura et munda ab omni extranea qualitate, ne per illam extraneam qualitatem impediatur propria operatio medicinae, et per consequens cognitio experimentalis.” This is the same as Peter’s first condition. Also as the passage from Galen’s Medicinal Simples, II, 5, quoted in John’s Concordances, “Oportet quod res quae experitur sit pura et denudata ab omni qualitate accidentali....”
[1685] I do not note this condition among Peter’s nor in the Concordances.
[1686] “Oportet quod medicina simplex experiatur in duabus contrariis aegritudinibus diversis, sicut scamonea in quotidiana et tertiana, ipsa enim curat quotidianam ex sua complexione, tertianam ex proprietate sua, tamen non sequitur, scamonea curat tertianam, ergo est frigida; sed sequitur, ipsa ex sua complexione curat quotidianam, ergo est calida.”
The use of the word “proprietas” for occult virtue is found also in Arnald of Villanova and other medieval writers.
[1687] John’s third, fourth and fifth conditions do not exactly correspond to any of Peter’s, but are contained in the following quotation from Galen (simpl. med. I, 2) in the Concordances. “Ad hoc ut res recte experiatur, tria requiruntur: 1m est ut experiatur in re ad quam comparatur, ut helleborus in coturnice non in homine; 2m requiritur ut distinguamus inter opus quod facit res per se et quod facit per accidens; 3m oportet cavere ne complexio actualis obnubilet potentialem et de omnibus his exempla ponit.”
[1688] “experimentum in corpore humano et primo in temperato, postea in lapso, et postea in aegro.” These last two conditions correspond to Peter’s last two and are also duplicated in John’s Concordances from Galen: “Si videris 5 vel 6 homines qualibet medicina mobiles, experimento solo non potuisti certiorare ilia medicina omnes homines posse moveri.... Oportet cum res experitur ut primo experiatur in corpore temperato et postea in intemperate.”
[1689] See the foregoing footnotes and Pagel’s text (1894), pp. 102-4.
[1690] Expositio in Antidotarium Nicolai, fol. 268, “... et hoc patet per experimentum accipiatur virga coryli recens et scindatur per medium medullae et ponatur frustum unum in manu una et aliud in alia manu, adinvicem coniungentur et hoc est quia unam alteri natum est conjungi naturaliter quia ex eis fiebat naturaliter unum conjunctum, et ideo unum natum est alteri conjungi excitatum per virtutem alterius. Et per illud faciunt vetulae carmen suum in matrimonium: dicunt enim quod quando aliquis desponsat aliquam, quod illae virgae coryli si conjungantur matrimonium erit ad bonum, si non, non: sed dicunt carmen aliquid operari ad hoc quod nisi dicerent, conjungerentur tarnen sive ad bonum sive ad malum.”
[1691] HL XXI, 263-5.