The study of botany as an independent science was not very widespread in the medieval Islamic world. Most of the botanical treatises written in Arabic during the Middle Ages were lists of names and descriptions of plants, giving information about their medical properties or their cultivation, rather than systematically studies aimed at classifying them, according to a scientific criterion. Given this background, the few ‘scientific’ works on botany that were produced are of note. Some of the most outstanding Aristotelian philosophers in medieval Islam devoted writings to a theoretical study of plants; these were often patterned on the pseudo-Aristotelian treatise On Plants. The text of this treatise, which is in reality a compendium of the authentic treatise De Plantis by Aristotle and of parts of Theophrastus’ Historia Plantarum, written in the first century BC, by Nicolaus Damascenus, was translated into Arabic around 900 AD, providing thus a good model for Arabic botanical literature. It inspired Avicenna’s treatment of plants in the relevant section of his al-Shifā’, as well as Ibn Bājah’s Discourse on Plants (Kalām ... fī al-Nabāt):both these works are extant and have already been edited, the former in19651 and the latter in 1940.2 The eleventh-century Nestorian philosopher Abū al-Faraj ibn al-Tayyib from Baghdad, a well-known commentator of Aristotle, also wrote a Book of Plants. A part of this text, which appears to be quite extensive, was published in the 1989 volume, On Plants, devoted by Hendrik Joan Drossaart Lulofs and E.L.J. Poortman to the pseudo-Aristotelian medieval tradition3. Finally, another scientific study of botany, inspired by Greek sources, is found in the twenty-first of the Epistles of the Brethren of Purity (Rasāʾil Ikhwān al-Ṣafā), which has been edited on more than one occasion4.
These facts lead us to think that Averroes, the most renowned Arabic commentator on Aristotle, should also have devoted a work to botany. As a matter of fact, although there is some, albeit scant, evidence of the existence of this work, its text is yet to be found. It is certainly true that medieval Arabic bibliographical lists of Averroes’ works do not mention such a work. The most recent account of Averroes’ life and works, by Miguel Cruz Hernandez lists, is Talkhīṣ Kitāb al-Nabāt5, but this attribution is actually the result of a bibliographic mistake. Cruz Hernandez points out that the only Arabic manuscript containing this text is in Istanbul, Suleymaniye, no. 1179, a codex which in reality - as was first pointed out by Maurice Bouyges more than 70 years ago6 - contains only the Arabic translated text of the pseudo-Aristotelian On Plants. Apart from this bibliographic entry, the most complete treatment of the question of Averroes’ Book of Plants is found in Lulofs and Poortman’s abovementioned book, where a number of pages are devoted to a study on its existence7. I will discuss below all the available information we have about Averroes’ supposed work, according to the research undertaken by Lulofs and Poortman.
Apparently, Averroes himself quotes his botanical work in the fifth book of his medical encyclopaedia, al-Kullīyāt fī al-Ṭibb, where he devotes three chapters (27, 28 and 29) to a study on the taste’s , smell’s and colour’s characteristics – three subjects which occupy a key place in medieval Arabic treatises on botany. In particular, in Chapter 27, Averroes gives a detailed description of bitterness, by giving first his own opinion; then mentioning the physicians’ opinions on the subject and adding in conclusion: ‘What we have said about the bitter has already been explained in the Book of Plants8’. Surely, Averroes is not referring here to the pseudo-Aristotelian On Plants, because the book, as it was known to the Arabs and as it has come down to us, does not contain any reference to this subject. Moreover, the text of this passage, as found in the medieval Latin version of al-Kullīyāt (quod nos diximus de amaro, invenitur in libro nostro qui dicitur de Plantis)9,strongly leads us to think that the philosopher was referring here to a work written by himself about plants. If so, one should note that it was not so strange for tastes’s description to be found in an Arabic work on botany. For example, in section 8 of The Book of Nabatean Agriculture (Kitāb al-Filāḥah al-Nabātīyah), where the generation of plants is dealt with, a study of the origins and causes of plants’ tastes, smells and colours is to be found10. In particular, taste seems to have been studied in relation to fruit’s and plants’ different characteristics.
In the preface to the edition of Aristotle’s works, which was published (together with Averroes’ commentaries in Latin translation) in 1550, in Venice, by the Juntas, a letter from the Venetian patrician Bernardo Navagero is reproduced11. While in Constantinople, Navagero had found, in the possession of some Muslim and Jewish physicians, a considerable number of works on Arabic philosophy, among which he listed Magna commentaria in libros duos de plantis by Averroes. In reality, it is likely that this title refers not to a commentary by Averroes, but simply to a copy of the Arabic translation of the pseudo-Aristotelian writing on botany. This hypothesis is strengthened by two considerations. First, one has to realise that, in medieval Arabic manuscripts, the pseudo-Aristotelian On Plants often bears the title Tafsīr Nīqūlāʾūs, or Exposition by Nicolaus, and Navagero might have confused the title Tafsīr with the name Tafsīr usually given to Averroes’ Long Commentaries on Aristotle. Secondly, it appears that Averroes’ Book of Plants, as far as we can suppose from the extant information about it, was not a ‘Long Commentary’ on the pseudo-Aristotelian work. If it were, each sentence of the source would have been commented on literally, a conclusion that cannot be drawn from the brief reference given in al-Kullīyāt. In addition, the title supposedly given to the book by Averroes himself, Kitāb al-Nabāt, assimilates it to the compendia of the various books, forming the Corpus Aristotelicum, written by Averroes, which, in medieval Arabic bibliographies and in some manuscripts, were often designated under similar titles. A compendium by Averroes did not usually include a simple summary of Aristotle’s work, but was instead a re-elaboration of the contents of the latter and also included some subjects which were not found in the source12.
Lulofs and Poortman finally came to the conclusion that a passage from Averroes’ botanical writings was quoted, in a Hebrew translation, in Shem Tov ibn Falaquera’s “The Opinions of the Philosophers”, a Hebrew philosophical-scientific encyclopaedia written around 1270 in Spain. According to Lulofs and Poortman, the passage corresponds to the third chapter of the fourth book of Falaquera’s encyclopaedia, which deals with the general characteristics of plants13. This chapter begins with the formula: ‘Averroes said’, and explains that the nature of plants is determined by four criteria: 1. the place where they grow; 2. the wider geographical area where they flourish; 3. their growth season and 4. Their behaviour. This general statement is followed by a tentative classification of plants according to these four criteria. Plants are divided into the ‘perfect’ and the ‘defective’, the latter lacking some of the well-known plants’ characteristics, such as flowers and leaves. In the final section of the passage, some peculiarities in the development of plants are listed: for example, it is said that some of them do not produce fruit because they are too fatty. The chapter clearly elaborates on some of the contents of the pseudo-Aristotelian work On Plants, but also contains new material. Lulofs and Poortman, having failed to find any correspondence to it in any of Averroes’ extant works, concluded that it was taken from Averroes’ Book of Plants. In reality, as I have shown in a recent article14, the first 40 lines of Falaquera’s chapter correspond to a passage from Chapter 30 of the fifth book of al-Kullīyāt, which deals with plants’ characteristics, in the same way, as the simplicia. In any case, as I will prove, this fact does not rule out that Falaquera was really, in this instance, quoting Averroes’ lost botanical work.
Falaquera’s fourth book in his The Opinions of the Philosophers, where the above-mentioned chapter is found, is especially devoted to a study of botany and is a very interesting collection of several theories on this subject, composed by medieval Arabic philosophers. Like most of Falaquera’s works, it consists largely of quotations15. The first chapter in particular – published in Lulofs and Poortman16 - is a summary of the pseudo-Aristotelian On Plants: it explains how life is manifested in plants; the presence or absence of characteristics usually associated with life, such as nutrition and sleep; the parts of plants (fruits, leaves and so on); their inner composition and as well as the different places in which they grow. The second chapter – which is still unpublished - is devoted to the generation of plants and their species: first there is an analysis of those of vegetative soul (drawn from the Epistles of the Brethren of Purity); secondly, there is a description of the ‘chemical’ features of the various parts of plants (largely based on Averroes’ Epitome and Middle Commentary on Aristotle’s Meteorology) and thirdly, there is a discussion about the respective position of plants and animals among living beings (also taken from the Epistles of the Brethren of Purity). These chapters do not seem to assist the reconstruction of Averroes’ botanical treatise, but in the fourth chapter of Falaquera’s writings, which is also unpublished, we find subjects which correspond to the contents of Averroes’ work, as it was summarised in the reference, given in al-Kullīyāt. In fact, this chapter includes a discussion on tastes, smells and colours that correspond to the doctrines found in some of Averroes’ extant works. The description, particularly, of smell and colour, is almost identical to that given in Chapters 28 and 29 of the fifth book of al-Kullīyāt, and some sentences in the discussion on taste are very similar to the relevant passages in Chapter 27, as well as parts of Averroes’ commentary on Avicenna’s Urjūzah17. The discussion on tastes is rather wide: it covers four pages in the Hebrew manuscript of Parma, (Biblioteca Palatina, parmense 3156) which is one of the two extant complete manuscripts of Falaquera’s encyclopaedia (the other being Leiden, University Library, Or. 4758). The principles found in it, are also very interesting, because the treatise focuses more on tastes as the ‘chemical’ properties of plants, rather than as human sensory perceptions. What also distinguishes it, as Averroes’s work, is the fact that this fourth chapter, which contains the discussion, comes immediately after a chapter which is presented by Falaquera as being an Averroes’s quotation.
An English translation of the discussion on tastes found in Chapter 4 follows, according to the preserved text in the Parma manuscript. A comparison of its principles with the similar principles found in Avicenna’s al-Qānūn, Book II, Treatise 1, Chapter 3,18 as well as in Averroes’ above-mentioned medical works, appears in the notes.
The Parma manuscript, Biblioteca Palatina, parmense 3156, ff. 134v2-136v23
We have to speak about what indicates the nature of plants. We say that the things that indicate plants’ nature are: taste, smell and colour. We begin with taste and say that, since all the bodies are composed of the four elements and the proportions of elements are not the same in the composition of bodies, many properties result from the difference of these proportions, and tastes have many different properties too, due to differences in the proportions. Since tastes are many, an organ is needed for distinguishing between what is tasty and what is not: this organ is the tongue. Since the tongue possesses many nerves, it is very sensible.
The root of every taste is twofold: first, a moist watery element and secondly, a dry earthy one. One can see this in fruits: at the beginning of their production, fruits are moist and watery, like watermelons, cucumbers and their similar; when time passes and fruits receive water’s moisture earth’s substance and air’s thinness, the inner natural warmth and the outer airy warmth affects them. Then, the fruits develop and grow, their earthiness decreases, and their moisture solidifies; they acquire many tastes, according to the nature of the plant from which they are produced, the proportion of their coldness and hotness and the quality of their substantial moisture, which can be thick, thin or intermediate. Because of this, fruits pass from different species of tastes to others: for example, from pungency to sweetness, or as with grapes, from pungency to sweetness through acidity.19
The taste is what influences the sense of tasting, and that influence may be pleasant or unpleasant. Everything which the tongue tastes either takes effect or not on the sense of tasting. What does not take effect on the sense of tasting is tasteless.
What is tasteless is divided into two categories: first, a simple element, like water and the other similar ones, because they are tasteless, and secondly, a composite element. The latter is divided into three types: first, what has a watery substance, like a moist cane; secondly, what has an earthy substance, which is dry, like the mulberry, or what is called al-nashāʾ in Arabic (i.e. cornflour) and what something similar, and thirdly, what has a viscous substance: it is moist, like oil, albumen and animal fat.
What takes effect on the sense of tasting is divided into two categories: first, pleasant and secondly, harmful. The pleasant equates with what is pleasing to us, and is similar to the temper of the human [f. 135r] body. The temper of the human body is hot and moist in an intermediate way; because of this, that, which tastes pleasant to the tongue, is similar to the effect caused by tepid water on a cold body. If the substance of water prevails in it, that which is pleasant is called ‘sweet’; if the substance of air prevails in it, it has the same effect, but without a clear pleasantness - and this is called ‘fat. Because of this, every food is either sweet or20 fat, or both; and every food with one taste only, is not like a food, but rather like a drug.
An element’s sweetness indicates an intermediate state in hotness and moisture, and therefore it is proper for nourishing the human body with, more than one taste21. Because of this, Galen said that something has a little or great degree of sweetness22, according to its closeness or distance from the nourishment. This does not imply that what is sweeter is more nourishing because nourishment needs other things, apart from sweetness23. Based on that assumption, he said that nourishment is not only what is pleasant to the sense, but also what is received and digested by the limbs, and transformed into the nourished thing’s nature.
What is harmful is what produces damage through its bite. Biting is a type of melting of a single thing, and what melts a single thing takes effect either by dividing much or by collecting much: what melts by dividing much is hot, and what melts by collecting much is cold.
What is hot is divided into two categories: first, earthy and secondly, fiery. The hot earthy species are divided into two types: one type removes and washes away everything that is grasped by the tongue by dividing its parts - and this is called ‘salty’; the other is stronger and divides its parts in a more forceful way - and this is called ‘bitter’. The hot fiery species are called ‘acute’.
What is cold is divided into two categories: first, earthy and secondly, watery. The earthy aspect of cold, when it falls upon the tongue, either sets and dries it, or makes the opposite, that is, it divides it strongly - and this is called shāʿir . This is akin to the effect caused by unripe figs, namely ‘pungent’, or an inferior effect to it called ‘setting24’. The difference in strength between ‘pungent’ and ‘setting’ is clear, and ‘setting’ is also referred to in the genus that embraces both. The watery cold that produces effervescence is called ‘acid’.
Now it is clear that there are eight categories of taste and tastelessness: fat, bitter, sweet, salty, acute, setting, acid and pungent25.
The tasteless one derives from the mixture of an intermediate temper with an intermediate substance. The bitter derives from the mixture of a hot temper with a thick substance. The acute derives from the mixture of a hot temper with a thin substance. The setting derives from the mixture of a cold temper with a thin substance, mixed with earthiness. The pungent derives from the mixture of a cold temper with a thick substance, and all that are related to man’s intermediate temper26. By knowing this, man knows the nature of plants and their virtues. That which is tasteless is a watery substance, belonging to sweet’s category, but since watery moisture is mixed with it, its sweetness is much reduced27. Due to this, the fruit which is found higher up on the plant is sweet, whilst that which is nearer to the earth is tasteless, because the watery substance prevails in it as a result of the abundant moisture arriving there. This happens, for example, in wheat, barley and beans, because all of these initially, are almost tasteless, yet when they are cooked and dried they become sweeter.
Fat is pleasant and sweet too, and its substance is watery and airy, like animal fat, olive oil, olives and other things from which an oil is produced. The fattiness and the sweetness belong to the same genus of hotness and moisture, but the difference between them is that the moisture of the sweetness is viscous and thick, mid-way between thickness and thinness, and fits the moisture of the human body, while the moisture of fattiness is pleasant and thin, and is similar to the air’s moisture28. Because of this, fattiness is the more proper of all tastes for nourishing natural warmth; this is proved by the fact that olive oil and oily substances provide man with an outer nourishment: this because the moisture of olive oil and its substance fits the moisture of air, and air is nearer to the nature of fire than other elements, because both fire and air are hot.
The substance of that which is sweet is intermediate, and29 all sweets are hot, but they differ in their heat intensity, according to their different degree of sweetness: this because the more something is sweet, the more it is hot. However, the hotness of something sweet does not generate harm, since its hotness is close to our bodies which are hot. The definition of sweet is what nourishes but it is sweet in two senses: first, because of its own natural hotness, like honey, and secondly, because of an outer hotness, like that which is cooked [f. 136r]. Sweetness is divided into four types: first, pure and absolute sweetness, in which the different elements are made equal, as in sugar; secondly, sweetness mixed with a viciousness and thickness, as in dates; thirdly, sweetness mixed with a tastelessness: the substance of its moisture passes from thickness to an intermediate state, and from less to more; its hotness decreases and its sweetness becomes weak, as in pomegranates, and fourthly, sweetness mixed with acuteness: the substance of its moisture passes from thickness to thinness, from more to less and to dryness. Acute sweetness is like that, provided by honey. Therefore, pure sweetness deprived of acuteness and viciousness, indicates an intermediate state, and is similar to man’s temper.
The salty and its taste are close to the bitter, because both are earthy and hot, but the difference between them is clear, because bitterness is the taste which is made thinner by a dry hotness, and its substance is heavy, while in a salty substance a dry and burnt element prevails, which is mixed with moisture, and this is superior to the sweet in its hotness30. The salty is like bitterness broken by cold moisture; because of this, when the salty is heated by the sun or by fire and the wateriness – which breaks hotness’s influence - is separated from it, it becomes bitter31.
The bitter has a thin earthy substance: this does not mean that it is absolutely thin, but that it is thin because of earth’s nature of, like dust. If somebody compares the bitter to something belonging to smoke’s genus caused by a flame, he is right, because that smoke has a bitter taste; and a heavy earthy body is, for example, stone and iron, while a thin earthy body is, for example, smoke and dust.
The bitter’s nature is where the dry earthy substance prevails, either with its coldness [or with its hotness]32, and this is proved by the fact that the bitter which derives from coldness becomes sweet after having been bitter, like many plants, for example, pumpkins, while the bitter which derives from earthiness and hotness, after having been sweet, returns to bitterness. This characteristic of that which is bitter, indicates that it is the result of a mixture of two tempers, hot and dry or cold and dry, like black, which derives from a mixture of hotness and coldness33.
Since the substance of bitter is heavy, the pure bitter, does not permit the mould, in which an animal is created, and the pure salty does not nourish the animal34. Therefore, when their saltiness is removed [f.136v], the seas become bitter, like the Dead Sea, and because of their bitterness, no animal can survive in them35.
The acute has a thin fiery substance, and the meaning of ‘acute’ is that the tongue becomes very hot and is bitten when it tastes it. It is hotter than other tastes; the salty, the bitter and the acute belong to the same genus of hotness and dryness, but the difference between them is that cause’s moisture is thin and fiery, salty’s moisture is intermediate between thinness and thickness, close to earthiness, while bitter’s moisture is thick and earthy.36
The setting is a weak pungent taste; both the setting and the pungent constitute setting, but they differ in their degree of settings37.
The pungent is colder, the setting follows, and then acidity. Because of this, fruit has, at the beginning, a strong acidity which makes it extremely cold. When airiness and wateriness develop in it and acidity is slightly moderated by them and by the heating of the sun which heats it, the fruit adopts an acidic taste, like unripe fruit, and in the meantime it is leaning towards the setting, and is almost pungent; thereafter, the hotness which heats the fruit provokes its sweetness; fruit can also pass from pungent to sweet without passing through acidity as the olive does38.
Acidity indicates a coldness, which is mixed with some moisture, and it bites the tongue in an intermediate way, without heating it. The pungent, the setting and the acid pertain to the same genus in their coldness and dryness. The difference between them, however, is that pungent’s moisture is very scarce, thick and earthy, setting’s moisture is larger and closer to the intermediate, while acid’s moisture is larger and thin39.
To sum up, I think that it cannot be ruled out that not only Chapter 3 of Falaquera’s fourth book in his The Opinions of the Philosophers (as supposed by Drossaart Lulofs), but also Chapter 4 (partially translated above), reflect the contents of Averroes’ lost Book of Plants. I am led to this conclusion by the following considerations.
First, it would be strange if the complex tastes’ systematisation, given in the above text, were composed by Falaquera himself. In his encyclopaedia, he always reproduces Arabic sources and his personal interventions are very limited (one or two sentences inserted here and there). Moreover, he introduces Chapters 3 and 4 as a quotation from Averroes. These chapters give a rather complete theoretical description of botany, as it was understood in medieval Arabic science: a general classification of some plants’ characteristics (Chapter 3) followed by an analysis of their ‘chemical’ features - taste, smell and colour (Chapter 4) and we know from Averroes himself that taste, and the bitter in particular, was one of the subjects of his Book of Plants. Finally, one has to note that Falaquera’s analysis of the bitter would fit well with what Averroes says in al-Kullīyāt about his own analysis on the same subject in his botanical work40.
Secondly, it should be stressed that, if Averroes’ Book of Plants pertained (as appears from its very title) to the genre of the compendia of Aristotle's works, it might have been written around 1159, when Averroes wrote the whole series of compendia on Aristotle's natural sciences works (except for the zoological).41 Since al-Kullīyāt was written afterwards, in 1162, it is not far-fetched to think that Averroes re-used some parts of his Book of Plants for writing the sections of his medical work devoted to the study of plants, as simplicia (Chapters 27 to 30 of the fifth book). This would explain the fact that so many passages of the text quoted by Falaquera correspond more or less to the relevant passages of al-Kullīyāt.
Finally, the literal correspondences of some text’s brief passages, quoted by Falaquera, to parts of Avicenna’s al-Qānūn might result from the fact that Averroes employed the latter as a source for writing the Book of Plants. This would not be so strange: apparently, Averroes used to employ in some of his works, especially medical texts, literal quotations from Arabic sources, without any explicit reference to them. In al-Kullīyāt, for example, he reproduces almost literally, some passages from the anatomical works of Abū Bakr al-Rāzī and al-Majūsī,42 as well as, in its preface, most of al-Fārābī’s Epistle on Medicine (Risālah fī al-Ṭibb).43
Of course, these points are not sufficient for reaching any definitive conclusion about Averroes’ Book of Plants: the question will only be solved if the original Arabic texts, or explicit quotations from it in Arabic, Hebrew or Latin, are discovered. My sole aim has been to point out a neglected theoretical passage on tastes, which, as far as we know, would fit well with the characteristics and contents of this work and which, therefore, constitutes an interesting witness to medieval Arabic ‘scientific’ botany.
This was published in:
The Earth and its Sciences in Islamic Manuscripts: proceedings of the fifth conference of Al-Furqān Islamic Heritage Foundation – English version, 2011, Al-Furqan Islamic Heritage Foundation, London, UK., p 269-292.
Please note that some of the images used in this online version of this article might not be part of the published version of this article within the respective book.