Multiple Discoveries, Discovered Multiply

Part 1: Merton’s multiples

If there be nothing new, but that which is
Hath been before, how are our brains beguil’d,
Which, labouring for invention, bear amiss
The second burthen of a former child!

William Shakespeare, Sonnet 59

This blog is setting sail as a stan account of Robert K. Merton. I first came across the name in a book titled “Sleeping Beauties: The Mystery of Dormant Innovations in Nature and Culture” (it was one of those books that could have been a blog post but is still worth a quick read). Robert K. Merton,¹ it turns out, is the founder of the fields of sociology of science AND sociology of crime and deviance. Many of the sociological concepts now firmly embedded in everyday language owe their origin to Merton: ‘unintended consequences’, ‘role model’, ‘reference group’, ‘self-fulfilling prophecy’, ‘self-defeating prophecy’, ‘Matthew effect’ (with Harriet Zuckerman).

Merton authored a compendium of essays “The Sociology of Science: Theoretical and Empirical Investigations” ranging from establishing sociology of science as a distinct discipline to examining the reward system of science. The essays² that caught my eye at first were on the subject of multiple discoveries in science, since this was also the context in which I initially encountered Merton’s name.

Multiple discoveries, now also referred to as Merton’s multiples, happen when the same discovery or technological invention³ is made independently by multiple people - within a span of decades to years or even weeks. There can be debates as to what is meant by ‘the same’ in this context but let’s put that aside for now.

I will divide the subject into 3 parts: this post will look into historical examples of multiple discoveries, in the next one I will go through the evidence of their ubiquity (so it’s not just isolated examples), and the third post in the series will consider what this says about “the shape of human ignorance” and what sociological and economic implications of multiple discoveries (MD from now on) are.

The most amusing thing about MDs is they are an example of themselves. “Almost,” says Merton, “it is a Shakespearean play within a play.” He notes that before him, at least 18 different historians of science and scientists themselves put together lists of varying lengths tallying MDs. The most famous study among them is by Ogburn & Thomas (1922) titled “Are inventions inevitable? A Note on Social Evolution”, documenting some 150 of MDs.

Without going too far back, in 1828 Lord Macaulay, a British historian and Whig politician, wrote about how the independent discovery/invention of calculus by Newton and Leibniz is an example of a larger class of instances of independent discoveries. He also notes that, for example

the doctrine of rent, now universally received by political economists, was propounded, at almost the same moment, by two writers unconnected with each other. Preceding speculators had long been blundering round about it; and it could not possibly have been missed much longer by the most heedless inquirer.

I’ll name a couple more curious examples from Merton’s list of people who made lists of MDs:

• in 1862-1865 the London Times, in light of the controversies over the patent system, published an entire roster of MDs, noting that “that the progress of mechanical discovery is constantly marked by the simultaneous revelation to many minds of the same method of overcoming some practical difficulty” (13th September 1865).
• in 1869 Francis Galton in his Hereditary Genius, considered “it notorious that the same discovery is frequently made simultaneously and quite independently, by different persons” (in part referring to the Darwin-Wallace doublet in evolutionary theory), and returned to this subject in 1874, in his English Men of Science.
• in 1906-1913 Pierre Duhem, the physicist-chemist and one of the fathers of the modern history of science, documented MDs and their implications in all of his major works of that period.

Ogburn and Thomas (1922) mention, among their 150 examples of MDs, that the pendulum clock was invented at least three different times, the thermometer seven times and the telegraph four times. The most famous inventors of the telephone are Alexander Bell and Elisha Gray (1876) but even before them, there were Antonio Meucci (1854) and Philipp Reis (1861) who came up with their own versions of the device.

Sometimes the fact of a multiple comes to light when unpublished results of a scientist become known, often posthumously. Henry Cavendish, for example, independently arrived at what we now know as Ohm’s law relating electrical current and voltage, and also discovered that combusting hydrogen produces water. But this wasn’t revealed until after his death in 1810. Augustus Harcourt published some of his work in chemistry in 1839, James Clerk Maxwell - his work in electricity in 1879, and Sir Edward Thorpe - his complete works in chemistry as late as in 1921. In the meantime, many of Cavendish’s unpublished results were independently discovered by his contemporaries and later researchers.⁴

Likewise, many important results in mathematics in the 19th century turned out to be multiples when Carl Friedrich Gauss’s private notebooks were unearthed and thoroughly studied. These include non-Euclidean geometry, quaternions, and Gauss–Seidel method for solving systems of linear equations (described by Gauss in 1823 and independently published by Seidel in 1874), among many others.⁵

Some published works are as good as unpublished because of their impenetrable prose or publication in obscure outlets. It has been said of Gibbs, of Gibbs free energy fame, that “it is easier to rediscover Gibbs than to read him."⁶ (I will go more into this phenomenon in another post.)

Is it surprising that MDs happen and in such abundance? It was to me, even being aware of some of the most colorful textbook examples. So it was also - or at least noteworthy if not entirely surprising - to many people who took pains to document them, though it seemed a matter of course to others. Merton writes, in his characteristically eloquent prose:

the theory [of multiple discoveries] was most unevenly diffused among scholars and scientists. By the middle of the nineteenth century, it had become, for some, a commonplace and often deplored truth; for others, it represented an entirely new conception of how science advances through the uneven accumulation of knowledge and through immanently or socially induced foci of attention to particular problems by many scientists at about the same time.

Further, Merton suggests that

the pattern of independent multiple discoveries in science is in principle the dominant pattern rather than a subsidiary one. It is the singletons - discoveries made only once in the history of science - that are the residual cases, requiring special explanation. Put even more sharply, the hypothesis states that all scientific discoveries are in principle multiples, including those that on the surface appear to be singletons.

I will go into the evidence supporting this (seemingly outlandish!) hypothesis in the next post. Thanks for reading!

Many thanks to Ashley Zhang and Santi Ruiz for their feedback on a draft of this post!

If you have comments on this post, feel free to get in touch on twitter/X or email me at aghayeva.u@gmail.com.