Goethe and the affinity between chemistry and literature

In 1809, Johann Wolfgang Goethe published his novel entitled Elective Affinities, also known as Kindred by Choice, which refers to one of the problems that had preoccupied chemists during the past century. Goethe’s work employed chemical affinity as a metaphor and applied it to romantic relationships, but did so once this concept was considered from the new perspectives provided by modern chemistry.

The years preceding the 1809 publication of Elective Affinities are replete with personal and intellectual events that can explain the mixture of literature and science, and the air of fatalism and rebellion woven into the novel. On a personal level, Johann Wolfgang Goethe had just turned fifty at the start of the century, and at that time this was an age which signified entering the final stages of life, in most cases, although in fact the German author lived to 82. In 1801 he was informed of a kidney condition which was to become chronic. Four years later –in 1805– his friend Friedrich Schiller died and in 1808 he lost his mother, to whom he had been very close.

Concerning his intellectual activity, it is as renowned as it is diverse, revealing the poet’s varied interests. In 1808, he finished the first part of Faust, a closet drama that took a lifetime to write and was not completed until shortly before his death; meanwhile, he continued to work on Wilhlem Meister. In 1803, he also took over the running of the Natural Sciences Institutes at the University of Jena, publishing several studies on botany and Metamorphosis of Animals (1806). Shortly afterwards he began his Theory of Colours (1809-1810), which was to scientifically discredit him given his vehement criticism of Newton’s work.

It is during this productive but turbulent period –in 1806 Weimar was occupied and looted by Napoleon’s army– when Goethe was writing a novel, whose very title takes a chemical metaphor that seems set to show humans’ limited ability to cope with a fate that seems relentlessly set by inescapable laws. We are in the nineteenth century, the era of rationality and calculation, and everything seems well-ordered and predictable. The unfortunate young Werther is far from this state and Goethe seems to agree with the signs of the times when writing a novel that can almost be summarised in an equation. But perhaps this is too simplistic and the story can be interpreted in a variety of ways.

Chemistry lessons at home

First, we will discuss the novel and highlight the references made to chemistry. Edward and Charlotte relive a childhood romance, once thwarted by opposition from their respective families, getting married after both have been widowed. Their quiet life is disrupted by the arrival of a friend of Edward’s, the captain, followed by the arrival of Charlotte’s young niece, Ottilie.

«Goethe writes a novel whose very title takes a chemical metaphor that seems set to show humans’ limited ability to cope with a fate that seems relentlessly set by inescapable laws»

Both the title and the events that occur are ahead of their time, though little does the reader realise this on reading chapter four’s conversation between the married couple and the captain (Ottilie had not arrived yet). The discussion takes place during the course of a common practice at that time: group reading aloud. Charlotte’s attention is drawn to the word affinities and Edward explains its use in the book is metaphorical, referring to earths and minerals.

That, however, leads to an explanation by the captain, an educated man well-versed in science, regarding how the word is used. He says he read it some time ago and does not know whether the scientific world continues to think the same about it now. This gives rise to Edward exclaiming most annoyed that «one cannot now-a-days learn a thing once and for all, and have done with it» a statement Goethe uses to convey the idea of ​​an ever changing and unstable world.

«Such natures, when they come in contact, at once lay hold of each other, and mutually affect one another, we speak of as having an affinity one for the other», says the captain. And he cites alkalis and acids, as an example, whose affinities are strikingly marked, and which, being of opposite natures seek one another out, lay hold of each other, modify each other’s character, and form an entirely new substance. Edward says: «Affinities only begin really to interest when they bring about separations». And this last word seems to upset Charlotte, who exclaims it is heard too often in the world now-a-days.

The captain resumes his explanation with an example:

[…] Thus, what we call limestone is a more or less pure calcareous earth in combination with a delicate acid, which is familiar to us in the form of a gas. Now, if we place a piece of this stone in diluted sulphuric acid, this will take possession of the lime, and appear with it in the form of gypsum, the gaseous acid at the same time going off in vapour. Here is a case of separation; a combination arises, and we believe ourselves now justified in applying to it the words “Elective Affinity”; it really looks as if one relation had been deliberately chosen in preference to another.

Then Edward makes the following comment: «You mean me by your lime; the lime is laid hold of by the captain, in the form of sulphuric acid, torn away from your agreeable society, and metamorphosed into a refractory gypsum». Charlotte replies:

But man is far superior to such elements, and if in this case has behaved generously with the beautiful words such as “Choice” and “Elective Affinity”, he will do well to reflect on this occasion, on the value of such expressions. Unhappily, we know cases enough where a connection apparently indissoluble between two persons, has, by the accidental introduction of a third, been utterly destroyed, and one or the other of the once happily united pair been driven out into the wilderness.

Edward concludes: «Then you see how much more gallant the chemists are. They at once add a fourth, that neither may go away empty». Later, the captain gives a «coded» example:

Suppose an A connected so closely with a B, that all sorts of means, even violence, have been made use of to separate them, without effect. Then suppose a C in exactly the same position with respect to D. Bring the two pairs into contact; A will fling himself on D, C on B, without its being possible to say which had first left its first connection, or made the first move towards the second.

And Edward applies this generic explanation to their particular case, involving the married couple and their two guests:

Now then!» –interposes Edward– «till we see all this with our eyes, we will look upon the formula as an analogy, out of which we can devise a lesson for immediate use. You stand for A, Charlotte, and I am your B; really and truly I cling to you, I depend on you, and follow you, just as B does with A. C is obviously the captain, who at present is in some degree withdrawing me from you. So now it is only just that if you are not to be left to solitude, a D should be found for you, and that is unquestionably the amiable little lady, Ottilie. You will not hesitate any longer to send and fetch her.

Thus the plot of the novel is sketched, although Edward is not right –or is unwilling to recognise– the reactions that actually take place.

Charlotte and Edward, the married couple portrayed in Elective Affinities. Their relationship is altered when a friend of Edward’s, the captain, and Charlotte’s niece, Ottilie, come to stay. The events that take place are summarised in the conversation between the married couple and the captain, shown in the film version by a diagram the captain draws on the blackboard: If we have a closely connected couple (A and B) and there appears another similar couple (C and D), then A will be flung onto D, and C onto B. The picture shows different frames from the film Elective Affinities (1996), directed by Paolo and Vittorio Taviani. / Filmtre-Gierre Film

Afinity, a chemist’s puzzle

The affinity between substances, the reason why certain compounds are formed rather than others, and why some separate to be remade differently, concerned scientists in the later years of alchemy and early years of modern chemistry. Newton, who had already come up with an explanation for the attraction of bodies, went on to propose that the laws of gravitational attraction and of magnetism and electricity could be extended to the union and separation of substance and gave examples of the reactions between alkalis and acids. In the only article he published on chemistry –written in 1692 but published in 1710– and issues 31 and 32 of Optics, he proposed the existence of a very powerful force between the particles of substances, which varied from one species to another. He even put forward a short list of six metals ordered by priority on replacing one another when dissolved in nitric acid.

Eighteenth century chemists called this force «elective affinity». In 1718, the Frenchman Etienne-François de Geoffroy presented his Table showing different relationships observed between different chemical substances to the Academy of Sciences. During the presentation, Geoffroy observed that there are certain laws and a degree of preference so that when various substances are mixed together, there is a clear preference for some to bind with other specific ones. But he also stressed that if there is a third substance that has greater preference for one of the two, the substance will break up to form another.

Affinity was not a new idea, but Geoffroy tried to establish this order of preference. And by the mid-eighteenth century, dozens of tables of affinities had already been published. To discover the causes of these affinities and pinpoint which and how strongly substances were related would become one of the main issues of chemistry that century. And most authors entertained the belief that a force like gravitational attraction existed. However, Geoffroy did not mention it, probably because in Cartesian France at that time Newton’s success was unseemly, both from the intellectual and patriotic standpoint.

In 1775 another important text appeared on the subject. The author was the Swede Tornbern Bergman, and it was entitled Elective Affinities. The text was translated into German in 1782 and Goethe not only knew about it but, in a letter to a friend, acknowledged that the title of his novel had come from the title of this essay. We shall see that the similarity goes further than just the title.

We might suppose, then, that Goethe extracts from the title, some explicit references and even the plot of a current problem for chemists at that time. However, it must be put into context, because little by little the idea of affinity as it was formulated became vague and eventually disappeared. In 1803, Claude Louis Berthollet said that factors such as concentration, temperature or pressure affect affinity. He said that explained why attempts had failed to find laws and well-established quantitative relations, which would provide the foundations of chemical reactions as predictive as Newton’s laws that could predict the movement of the stars.

Goethe took the title Elective Affinities from the world of chemistry. The affinity between substances refers to the reason why certain compounds are formed rather than others, and why some separate to be remade differently. Above, Joseph Karl Stieler. Johann Wolfgang von Goethe, 1828. Oil on canvas, 63.8 x 78 cm. / Neue Pinakothek, München

Around the year in which Goethe’s novel appeared, scientists such as Humphry Davy and Jöns Jacob Berzelius had already begun to develop an electrochemical theory, thus providing a new approach to reactions between substances. In attempting to explain electrolysis, it appears that electrically charged surfaces, be they positively or negatively charged, affect the balance and can even alter the elective affinity that certain substances have. Then, further into the nineteenth century, works on chemical thermodynamics appeared, which would include new factors in the explanation of the affinity between substances. The expansion of industry also required these relationships to be characterised much more accurately, and even quantifiably.

At the end of the century, physical chemistry would introduce models and require mathematical calculations to explain reactions. Increasingly more factors influencing reactions were known and with greater accuracy. Then, in the late thirties of the twentieth century, Linus Pauling published The Nature of the Chemical Bond, which applied quantum mechanics to chemistry, explaining how atoms combine to form stable molecules and also why some form and others do not.

Altogether this shows us that, indeed, the so-called elective affinities were a prominent theme in eighteenth-century chemistry, but also that when Goethe published the novel, the notion had already been called into question, mainly due to the inability to establish it as the basis of a consistent and comprehensive explanation for the formation and destruction of compounds.

The laws of nature and human relationships

In any event, clearly Goethe’s metaphor goes well beyond the title copied from a scientific treatise of his time. The similarity between certain passages in the novel, cited above, and others in the book by Bergman should not surprise one. Thus, we are reminded of an explanation given by the captain when we read one proffered by Bergman:

Imagine we have a substance A which heterogeneous substances a, b, c attract: Suppose, moreover, that A combines with c to saturation point, which we designate as the binding of A and of c = Ac, b tends to bind when added, and separates from c. Then we say that A attracts b more strongly than c does, or that b has a stronger elective attraction than c. Suppose, finally, that Ab is decomposed by the addition of a, that b is separated, and that a takes its place, it will follow that the attractive force of a exceeds that of b and that of the series a, b, c, etc. will be exactly the order of strength of the attractive forces of these three substances.

According to Bergman, there is a natural order of substances, and he goes on to give specific examples. And here the explanation given by the captain using the example of limestone and acid would not be out of place.

But Goethe goes further than just introducing these references in the novel. In fact, the notion of elective affinity, of laws obliging certain unions but preventing others, is to be found throughout the book. That is why the end of the story witnesses the break up and rearrangement of the characters-substances and couples-molecules, but not as Edward had predicted. The substance that separates A (Edward) from B (Charlotte) is not C (the captain) but D (Ottilie). Likewise, Charlotte does not avoid being lonely thanks to Ottilie, but rather thanks to the captain. Hence, sometimes the novel has been outlined as follows:

AB + CD → AD + BC

Albeit CD fails to occur here, a couple comprising the captain and Ottilie never exists. But the fact is that if we analyse the nature of each character, the reaction was inevitable. Edward is immature, self-centred and temperamental. Ottilie is a very young girl, frail and inexperienced. Charlotte is rational and farsighted. The captain is also rational, but he is also clever, honest and resolute. If elective affinity works, then no other reaction is possible. Edward is bound to be attracted to Ottilie and Charlotte and the captain must end up together. It is even impossible, when the captain and Edward go off to war, that new suitors may have a chance with Ottilie or Charlotte: there is no affinity.

«The man who wished to go down in history as a scientist achieved mainly literary greatness that would overshadow his other facet. But even so, he sprinkled his narrative and poetic work with science»

Thus it highlights the inevitable way in which things work, a sort of social mechanism that works like a set of gears and constitutes an inevitable fate. It is clear that characters can rebel, but in the end what counts is the natural law, as happens with objects and substances alike. That does not retract from the fact that the novel is clearly romantic and that the ending is tragic.

As an addendum, we could take the metaphor and apply it to Goethe and his life’s work. Passionate about science, he went further than merely becoming well-versed and producing notable works –as well as colossal mistakes–. He was more than just a manager of technical studies and industrial structures. We find scattered throughout his writings numerous scientific references. The man who wished to go down in history as a scientist, achieved mainly literary greatness that would overshadow his other facet. But even so, he sprinkled his narrative and poetic work with science. It was as if the inescapable elective affinities had finally caused a reaction too, without breaking anything, a new valuable alliance was wrought between chemistry and literature.