Leibniz, Ibn Tufayl and the pre-history of a famous thought experiment anew (oh Mary)

After pestering me for a while to write the book, my friend Helen de Cruz has been sharing with me ideas to publish a book on the ways the Enlightenment is not this dogmatic, monolithic, and Eurocentric project some of its recent, false friends have made it out to be. I believe Helen plans to center it on Leibniz, who had capacious reading habits. Leibniz didn’t just contribute to the scientific revolution in the widest possible sense, but he also assimilated from many sources and was eager to share his excitement about them. Today’s post is dedicated to Helen with admiration and warmth.

A few days ago, Jake McNulty shared a passage from Leibniz’s On the Elements of Natural Science on social media. [Update: he has informed me he was inspired by this tweet by Joshua Watson.] This text is usually dated to ca 1682-4. It shows clear influence of Bacon’s New Atlantis on how to organize science. And in it Leibniz praises Mersenne. Along way, Leibniz defends a particular role for empirical enquiry in the context of what he calls, “Confused attributes;” these “are sufficiently distinguished only by being shown.” Leibniz explains this as follows:

It follows clearly from this, moreover, that attributes which are sensible can be divided into confused and distinct by intellectual principles. Confused attributes are those which are indeed composite in themselves or by intellectual principles but are simple to the senses and whose definition therefore cannot be explained. These attributes can be imparted not by description but only by pointing them out to the senses. Imagine a land where men do not know the sun and fire and have blood which is cold, not warm; surely they cannot be made to understand what heat is merely by describing it, for even if someone were to explain to them the innermost secrets of nature and even interpret perfectly the cause of heat, they would still not recognize heat from this description if it were presented to them, for they could not know that this peculiar sensation which they perceived in their minds is excited by this particular motion, since we cannot notice distinctly what arises in our mind and what in our organs. But if someone kindles a fire near them, they would at length learn what heat is.—Leibniz, G.W. “On the Elements of Natural Science.” In: Loemker, L.E. (eds) Philosophical Papers and Letters.

McNulty shared the passage from ‘Imagine’ onward. He accompanied the material with a “I guess there really are no new arguments in philosophy.” Some of his readers (and myself) assume McNulty had Frank Jackson’s Mary the scientist in mind. In this famous thought experiment, “Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black-and-white room via a black-and-white television monitor. She specialises in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like 'red', 'blue', and so on…What will happen when Mary is released from her black and white room or is given a colour television monitor? Will she learn anything or not? It seems just obvious that she will learn something about the world and our visual experience of it…”

Even if we recognize that Jackson’s point is distinct (he is arguing for the claim that qualia are left out of the physicalist story) from the function of Leibniz’s argument, I think Jake and his friends are right to see that there is a clear family resemblance between the structure of the thought experiments.

As an aside, Leibniz is often associated with the knowledge argument for different kind of thought experiments (including one from The Monadology par. 17 that is often treated as originator of the so-called ‘knowledge gap.’). So, I wouldn’t be surprised if the passage quoted from “On the Elements of Natural Science” had been associated with color-deprived Mary before.

Be that as it may, as regular readers may know, I am rather fond of Ibn Tufayl’s 12th century, philosophical novel, Ḥayy ibn Yaqẓān. A few years ago, in fact, I wrote a short piece, “Seeing color for the first time. Original thought experiment by Ibn Tufayl” for a beautiful and cheap volume edited by Helen de Cruz, Philosophy Illustrated (OUP). What makes it beautiful are not just the contributions (many of whom introduce their own famous thought experiments), but especially Helen’s lovely illustrations. (There is a podcast (here) about my contribution, alongside L.A. Paul, Tamar Gendler, Jennifr Lackey, and Peter Singer, etc.)

In my piece, I note how Ibn Tufayl anticipates the structure of Jackson’s (and Paul’s) argument. (I first made this point almost a decade ago on D&I.) Here’s Ibn Tufayl’s thought experiment in a 1708 translation:

Suppose a Man born Blind, but of quick Parts, and a good Capacity, a tenacious Memory, and solid Judgment, who had liv'd in the place of his Nativity, till he had by the help of the rest of his Senses, contracted an acquaintance with a great many in the Neighbourhood, and learn'd the several kinds of Animals, and Things inanimate, and the Streets and Houses of the Town, so as to go any where about it without a Guide, and to know such people as he met, and call them, by their names; and knew the names of Colours, and the difference of them by their descriptions and definitions [alone]; and after he had learn'd all this, should have his Eyes open'd: Why, this Man, when he walk'd about the Town, would find every thing to be exactly agreeable to those notions which he had before; and that Colours were such as he had before conceiv'd them to be, by those descriptions he had receiv'd: so that the difference between his apprehensions when blind, and those which he would have now his Eyes were opened, would consist only in these two great Things, one of which is a consequent of the other, viz., a greater Clearness, and extream Delight.--Abu Jaafar Ebn Tophail  The Improvement of HUMAN REASON, Exhibited in the LIFE of Hai Ebn Yokdhan [also known as Philosophus Autodidactus], translated by Simon Ockley (1708).*

Now, during the last decade I have learned there were many European editions and translation of it during the final decades of the seventeenth century. Most of them were based on a 1671 Latin translation by Pococke (whose father had found a medieval manuscript with a Hebrew translation of it) alongside an Arab original (see here). So, this (and a detail I withhold momentarily) made me wonder whether the voracious Leibniz was familiar with it.

In fact, Leibniz mentions the 1671 Latin edition in his correspondence. Here’s a passage from a letter from end of April, 1700 by Leibniz to Ludewig:

Non sine delectatione legi quae diss[eris] de philosophia Muhamedanorum rationali. Profunde philosophatos Arabes non aliunde magis constat, quam ex fabula Autodidacti, id est hominis qui infans in insula deserta expositus omnes artes et scientias per se eruit, quam jam latina versione edidit Pokokius, et quae ni fallor in Anglicam et nescio an non et in Germanicam linguam versa prostat.—Letter 358, Leibniz Akademie-Ausgabe, I, 18, p. 610

It was not without pleasure that I read what you have to say about the rational philosophy of the Muhammedans. The profound philosophizing of the Arabs is evident from no other source than from the story of the Autodidact, that is, of a man who, exposed as a child on a deserted island, learned all the arts and sciences by himself, which Pocoke has already published in a Latin version, and which, I am not mistaken, has been translated into English, and I do not know whether or not also into the German language.

The earliest such passage I found is from a 1697 letter of 3 February, 1697 to Abbe Nicaise, where Leibniz mentions Hayy, “Les Arabes ont eu des philosophes dont les sentimens sur la divinité ont esté aussi élevés que pourroient estre ceux des plus sublimes philosophes chrestiens. Cela se peut connoistre par l'excellent livre du philosophe autodidacte, que M. Pokok a publié de l'arabe.” [The Arabs have had philosophers whose feelings about divinity were as high as those of the most sublime Christian philosophers could be. This can be known from the excellent book by the self-taught philosopher, which Mr. Pokok (4) published from the Arabic.]

All of this is after when Leibniz had written, “On the Elements of Natural Science.” This annoyed me a bit, so I started to look at some secondary literature. In note 95 of a paper by Emmanuel Alloa, “The ‘Do It Yourself’ Paradigm: An Inquiry into the Historical Roots of the Neglect of Testimony” in Early Science and Medicine, I found a reference to Leibniz, Philosophische Schriften. Akademie-Ausgabe, vol. 6.4: Writings 1677-1690, Part B (Berlin, 1999), 1681.

The context seems to be Leibniz’s notes on Augustine’s Confessions for a work on Augustine’s metaphysics. Unfortunately, the material is undated. Although there is another related manuscript that can be dated to 1689-90. Anyway, after quoting Augustine’s famous proto-Cartesian passage “ego sum qui memini, ego animus” [I am a remembering kind, therefore I am animated/mind] with a reference to Confessions 10, c. 17, Leibniz adds “addatur locus Philosophi Autodidacti a Pokokio editi, quod corpus tantum institutum.” Sadly, I am unsure what passage Leibniz has in mind.

Okay, so I can’t prove that Leibniz read Ibn Tufayl before he drafted “On the Elements of Natural Science.” All I have demonstrated is that he exhibits familiarity with it subsequently.

However, there is a further hint that Leibniz was, in fact, modeling his thought experiment on the cold-blooded men unfamiliar with the Sun and fire on his reading of Philosophi Autodidacti. For the paragraph that I have quoted above ending with “But if someone kindles a fire near them, they would at length learn what heat is” concluded with another sentence, “Similarly a man born blind could learn the whole of optics yet not acquire any idea of light.”

We can rule out that this is a sloppy echo of Molyneux’s problem because Molyneux wrote his original letter to John Lock on 7 July 1688 (and Leibniz would not have learned about it until a few years later after the second 1694 edition of the Essay). And so I’d like to think this is early evidence of Leibniz’s creative delight in his encounter with Ibn Tufayl.