A Persian wunderkind born in the 10th century AD, Avicenna (the Latinized version of the name ibn Sīnā) knew a thing or two about plants. In addition to his enviable expertise in mathematics and physics, philosophy and astronomy, geology and Islamic theology, Avicenna was a practicing physician and the author of a five-volume Qanun, The Canon of Medicine.
For centuries after its composition, The Canon continued to be revered as the gold standard of the medical profession in Europe and outside its confines. This medieval state-of-the-art manual dealt with plants as the components of a human diet and, numbering in the hundreds, as remedies for sundry ailments.
Diet-wise, and contrary to what we might expect, Avicenna did not consider the consumption of fruits to be beneficial for human health. “Fresh fruits,” he categorically stated, “are only good for those who carry out hard work, or take much exercise […], for they render the blood too watery, and so it is apt to ferment.”(1) & Intense physical activity was recommended as a sort of antidote to counterbalance their adverse effects by purging the blood of vegetal “crude humours” and lightening the burden these imposed on the human organism. Shockingly for us, about one thousand years prior to the “Five-a-day” program, implemented by the US Department of Agriculture (USDA), fruits were seen as significantly more detrimental to human wellbeing than the meat of lamb and wine.
The curative property of plants was another focal point of The Canon and, at the same time, the point of convergence for Avicenna’s theoretical knowledge and some of the ill-fated events in his biography.
Take, for instance, celery. The philosopher-physician deemed this plant suitable for improving digestion and liberally prescribed its seeds as a diuretic remedy. When he, too, experienced the very digestive symptoms he had described, Avicenna did not hesitate to self-medicate in what he believed to be the strictest adherence to his manuscript’s guidelines. But things did not turn out the way he had expected.
Shortly before death, Avicenna accompanied the prince of Isfahan on a military campaign. Ceased by a colic attack and apprehensive that he would be left behind, he administered eight enemas to himself, causing his intestines to lacerate. Thereafter, he ordered an injection of two danāqs of celery seeds — a dose that was exceeded at least ten-fold when, ignoring explicit instructions, five dirhams of the extract were dispensed.
To make matters worse, having determined that he should take opium for the alleviation of epileptic symptoms, Avicenna received an overdose of the drug from his servants who used the occasion to rob their master. These incidents, sufficient to debilitate an average person, failed to slow him down, though. The sage continued to indulge in the dietary and sexual excesses, for which he was infamous, preferring to measure the days (and the nights) of his life in breadth, rather than in length.
Evidently, Avicenna learned a great deal from Aristotle, save for the patently Aristotelian virtue of moderation, that is, of finding an optimal middle course between surfeits and deficiencies. If we are to trust his biographers, the real cause of Avicenna’s death was vegetal excess: various overdoses of herbal medications, overeating, and, according to the disciple Al-Juzajani, sexual intercourse that was extremely frequent. Besides the actual celery and poppy seeds — the source of opium — directly implicated in the philosopher’s death, the two hyperactive dimensions of his vegetal soul — the nutritive and the reproductive — have also had a hand in his demise.
When pressed about the pitfalls of such a hectic lifestyle, Avicenna responded: “God, Who is exalted, has been generous concerning my external and internal faculties, so I use every faculty as it should be used.”(2) & In reflecting on his life, he did not seem to give much thought to the inner conflict among the faculties of the soul, nor did he reckon that some of them had to be controlled by other, more rational regions of the psyche.
Now, the immoderations of the philosopher’s life, associated in one way or another with the vegetal sphere, parallel his view of plants as carriers of ontological excess.
In their basic constitution, Avicennian plants are so chaotic and unstable that they are barely fit for receiving a soul. According to his cosmogony, or a theory of the origination of the universe, the elements of earth, fire, water, and air must come together in more or less balanced proportions to furnish matter capable of receiving a form (which is another word for a soul). Plants have something of this harmonious mix: “When the elements are mixed together in a more harmonious way […], other beings also come into existence out of them due to the powers of the heavenly bodies. The first of these are plants.”(3) & Closer to the state of equilibrium than minerals, plant matter is “disposed for receiving the vegetal soul.”(4)
Regardless of the thesis that plant matter is a definite advance on the crudeness of stones, it is the least balanced of all living beings. The subaltern position of plants at the bottom of the metaphysical hierarchy stays unchanged throughout the philosophical tradition; what varies is the justification of their presumed inferiority.
As Avicenna would have it, of all types of creatures, plants exhibit the greatest deviation from the mean. If an animal comes “after the plant,” it is because the former “emerges from a compound of elements whose organic nature is much nearer to the mean […] and is therefore prepared to receive the animal soul, having passed through the stage of the vegetable soul.”(5) & On a journey out of chaos and disharmony toward perfection, the soul must leave its vegetal shape, which Avicenna significantly calls “natural,” taby’yat, (6) behind.
Does the association of the vegetal with the natural bestow upon this stratum of existence a modicum of normality we usually attribute to nature? -Not at all. With reference to the measurements of pulse, Avicenna clarifies that the natural is, above all, that which is exceptionally strong and vigorous, “excessive as to strength.”(7)
Faithful to the Greeks in one respect, he parts company with them in another. As in ancient Greek philosophy, nature is still metonymically expressed in the plant, and it is for this reason that the faculties of the vegetal soul receive the appellation “natural.” But Avicenna’s nature is not exactly the total movement of self-generation and harmonious growth it represented for the ancients; it denotes, instead, excessive vigor in exercising a function or the disequilibrium of elements still lacking the cohesive force and form of the soul. The philosopher’s replica concerning the use of his faculties is, undoubtedly, tied to the first signification of the natural. Nature as vigorous excess in him and in the plant…
And yet, such “cherry picking” is untenable, since the two definitions of nature (hence, of vegetation) go together. That is why the vigorous use of the philosopher’s reproductive and nutritive faculties led to his ruination.
(1) Avicenna, The Canon of Medicine, translated by Oskar Cameron Gruner (New York: AMS, 1973), p. 404.
(2) William Gohlman, The Life of Ibn Sina: A Critical Edition and Annotated Translation (Albany, NY: SUNY Press, 1984), p. 83.
(3) Avicenna, Avicenna’s Psychology, (Oxford & London: Oxford University Press, 1952), p. 24.
(4) Avicenna, Livre de la Genese et du Retour, translated by Yahya J. Michot (Oxford: Oxford Centre for Islamic Studies, 2002), p. 64.
(5) Avicenna, Avicenna’s Psychology, p. 25.
(6) Avicenna, The Canon of Medicine, p. 107.
(7) Avicenna, The Canon of Medicine, p. 302.&