Until quite recently, rationalist Jewish scholars usually acquired their scientific knowledge from ancient Greek writers like Aristotle, Galen, Hippocrates or Ptolemy. However, when it came to the taxonomy of plants, it seems that they found a more straightforward source in the opening chapter of the Torah. Whereas Aristotle never adanced beyond a crude classification based on the plants’ sizes, the biblical account of the third day of creation spelled out in impressive detail the different kinds of vegetation: “...And the earth brought forth grass, and herb yielding seed after its kind, and the tree yielding fruit, whose seed was in itself, after its kind.”
Saadiah Ga’on appreciated that the scriptural text effectively reduced the unwieldy diversity of plant life into a more functional list of four basic types. At the bottom of the scale were “grasses” [deshe] that sprout directly from the soil without seeds; as an example he mentions (not quite accurately) hashish. Above them are the “herbs” [esev] that sprout from seeds, such as vegetable greens. At the top are trees, divided into fruit-bearing and non-fruit-bearing types. This classification is not unlike the one—“tree, shrub, undershrub and herb”— proposed by Aristotle’s disciple Theophrastus who is widely considered to be the father of ancient botany (though it is not clear whether Theophrastus’ writings were available to Saadiah’s scholarly milieu).
What was God’s purpose in furnishing his world with this particular assortment of herbs and trees? For the religious and philosophical thinkers of previous generations there was one answer: It was all provided for the convenience of the human race who stand at the pinnacle of the divine project of creation.
The discoveries of modern astronomy and cosmology have made it very hard to argue that we humans can lay claim to a special status in the universe. We are, after all, the inhabitants of what is no more than a micro-speck of dust in a cosmos whose vastness is inconceivable to our limited intelligences. The pre-Copernican creation was, in comparison, a cosier environment. Our planet stood solidly at the centre of a self-contained universe that—albeit huge by our puny mortal standards—was confined to the sun, moon and the planets of our solar system (at least, those planets that had been discovered by then) all of which circled eternally around our own world. This spatial arrangement corresponded to the values that underlie God’s creation according to the traditional outlook. The human residents of the earth occupy the most prestigious rank of all the beings in the universe, and all the other species are subordinate to us.
This basic position was articulated by Aristotle when he wrote that “after the birth of animals, plants exist for their sake, and the other animals exist for the sake of man, the tame for use and food, the wild, if not all, at least the greater part of them, for food and for the provision of clothing and various instruments."
Saadiah subscribed to the same principle, that the welfare of mankind is the ultimate purpose of all creation. He found support for that idea from the concluding summary in the Bible’s narrative of the production of plants on the third day: “and God saw that it was good,” which he understood in the sense of “good and beneficial to humans.” He also invoked the more explicit statement of the Palmist: “He causeth the grass to grow for the cattle, and herbs for the service of man, that he may bring forth food out of the earth.” The utility embodied in the plants is not confined to providing us with sources of nutrition; but it extends to our clothing (by means of vegetable-based fabrics like linen) and housing in protective wooden structures.
Judaism’s most prominent Aristotelian, Moses Maimonides, shared the view that everything that exists in our world exists solely for the sake of humans.
Both Saadiah and Maimonides were aware that this claim was not necessarily self-evident with respect to every species of plant that exists in our world. They anticipated people objecting that there are plants that produce toxic or lethal substances (as examples Saadiah mentions opium and spurges), and there are numerous plants that are just inedible.
To this argument the Jewish thinkers retorted that the impression that some plants are useless is an illusory one, the result of our limited perspectives on the totality of our world. In truth, the divine wisdom that manifests itself in nature dictated that every species of flora and fauna has a beneficial purpose if it is used correctly. As Maimonides put it, ”every grass or every fruit, or any animal species, from the elephants to the worms”—must benefit humans in some manner, even vipers and other snakes. In support for this thesis he noted that there are continual discoveries of herbal nutrients and medicines that had been unknown to earlier generations. Even species that are poisonous when ingested internally can have therapeutic benefits if applied externally. Therefore we have every reason to expect that future scientific discoveries will keep expanding our appreciation of nature’s service to the human race. Saadiah informs us that his Arabic commentary to Genesis includes an extensive digression about the pharmaceutical qualities of “every plant of the field ... and every herb of the field”; but apparently that digression has not survived.
The Jewish commentators were not in agreement about how to harmonize the Torah’s narrative of the creation of plants with their own scientific understandings of botany.
Saadiah’s reading of the relevant scriptural passage led him to conclude that the species that came into existence on that first Tuesday were not just seeds that later evolved into full-grown plants; but rather from the outset they appeared simultaneously as fully mature seed-bearing bushes and fruit-laden trees. Perhaps he was also drawing an analogy from the creation of the first humans who supposedly began their lives as mature adults. For that matter, the universe itself had been born out of utter nothingness in a single Big Bang, according to the doctrine to which most Jewish thinkers subscribed in spite of its apparent incompatibility with mainstream secular science.
A very different approach was advocated by Rabbi David Ḳimḥi of Narbonne. He believed that God’s activity on the third day consisted only of preparing the earth with the potential to produce the broad range of vegetation that would serve the needs of the the world’s denizens; even though those creatures would not actually come into existence until the succeeding days. After all, the sun would not be created until the fourth day. According to Kimḥi, the light that was provided on the first day of the creation did not radiate powerfully enough to support vegetation; hence, in his view the world could not yet sustain the growth of plants. The deshe / grass that was made on the third day was, in Kimḥi’s opinion, a kind of primordial generic meta-vegetation that would not evolve into real herbs until after the sun was fully installed the heavens. It was at that point that the soil would produce mature plants, and the trees would grow to their full statures.
Thus, in sharp contrast to Saadiah’s depiction of a world that came into being fully adorned with an assortment of ripened greenery, Kimḥi argued that God’s direct involvement in the creation of plants was restricted to a single exemplar of each species. These prototypes were imbued with the capability to reproduce, evolve and endure until they filled the earth.
Of course, by modern standards the invoking of scriptural texts can no longer qualify as valid botanical science. Nevertheless, the philosophical and theological issues raised by those early scholars can inspire some meaningful deliberations about humanity’s relationships with the other species with whom we share our world.
Such discussions can yield fruitful results.