The majority view
The current consensus among scientists and historians is that Darwin and Wallace independently arrived at their version of ‘macroevolution by natural selection’ (I’m using ‘macroevolution’ here as a short-hand for ‘the evolutionary origin of species’). Thus, all three deserve the title of independent ‘originators’ of this idea. This is also the view that I hold, barring new evidence.
(Aside: Milton Wainwright has argued that the word ‘originator’ implies the first, and so the term should not be applied to Darwin and Wallace. I like the word because of its neat double-meaning relating to the ‘origin of species’, so I prefer to use the word here in an alternative sense of ‘someone who independently came up with the idea of the origin of species via natural selection’.)
Under the majority view, Matthew’s ideas on macroevolution by natural selection had a minimal influence on the scientific community, at least until Matthew rebroadcast them in the Gardeners’ Chronicle following the publication of Darwin’s On the Origin of Species. The evidence in favour of this view is as follows:
- The only known published pre-1860 critique of Matthew’s ideas on macroevolution by natural selection is a brief review attributed to Loudon (1832), and Loudon professes himself unsure of whether Matthew ideas are original (suggesting that even well-educated naturalists like Loudon had difficulty in understanding Matthew’s novelty);
- Matthew himself, in a footnote to a later article (Matthew 1862e), admits that he did nothing to further promote his ideas on macroevolution by natural selection following the publication of his 1831 book.
- Darwin directly denied any prior knowledge of Matthew’s book (Darwin’s letter to the Gardeners’ Chronicle of 21 April 1860), while Wallace indirectly implied this by on the one hand conceding that Matthew had arrived at the same ideas as he and Darwin had (Wallace 1879) and on the other hand asserting that he had had an independent ‘eureka’ moment for himself (Wallace 1905) – see my “Wallace on Matthew” entry.
- Darwin’s notebooks describe a gradual groping towards a solution to the problem of the origin of species, not a sudden epiphany following the reading of Matthew’s book.
The minority view
A minority view holds that Darwin and/or Wallace were aware of Matthew’s ideas, or at least were indirectly influenced by them, and therefore Matthew is not only the first originator of this idea, but in fact the only originator of this idea. The recent champion of this view is Mike Sutton (see his blog, his 2014 e-book Nullius in Verba and his 2014 peer-reviewed article), but others who have contributed to this view include Loren Eiseley (1959) and Hugh Dower (2009 web article). Also noteworthy are William Dempster’s 1996 book Evolutionary Concepts in the Nineteenth Century: Natural Selection and Patrick Matthew (although Dempster never directly accuses Darwin of plagiarism) and Roy Davies’ 2008 book The Darwin Conspiracy (although he holds to a different thesis – that Wallace originated the idea and Darwin stole it from him). However, Davies also paints Darwin as duplicitous in the same way that Sutton does.
The minority view’s reply to the above points would be as follows (modern citations below indicate the author who uncovered or proposed the evidence):
- Although Loudon was the only one to critique Matthew’s evolutionary ideas pre-1860, several other people cited Matthew’s book for its practical advice on timber and arboriculture, including Prideaux John Selby (who later edited Wallace’s 1855 “Sarawak” paper) and (plausibly) Robert Chambers (later anonymous author of the influential pro-evolution book Vestiges of the Natural History of Creation) (Sutton 2014, “List 1”). Loudon (who later edited Edward Blyth’s papers on natural selection (Sutton 2014)) also cited Matthew’s book for its practical advice on timber and arboriculture several times in his encyclopaedic reference work Arboretum et Fruticetum Britannicum (Dower 2009), a work that we know (from his notebooks) that Darwin consulted (Dower 2009). The naturalists Edmund Murphy, Cuthbert Johnson, John Norton and William Jameson also cited Matthew’s book (Sutton 2014, “List 1”). The book was also quite widely advertised (Sutton 2014). The early adverts note simply that “the subject of species and variety” is considered, but the later adverts actively promote “the interesting subject of species and variety” and also directly refer to a principle (i.e. natural selection) which “keeps unsteady nature to her law”. Other reviews of the book also made oblique references to this aspect of the book. Additionally, other naturalists, for example David Low, did not formally cite Matthew’s book, but used unusual phrases (Sutton calls these “Matthewisms”) derived from it like “long continued selection”, and/or presented ideas similar to those in Matthew’s book, which might suggest they had read it too (Sutton 2014, “List 2”). Since many of the above people, and their publications, were known to Darwin and Wallace, the minority view argues that at least one of them would have been likely to have either told Darwin and/or Wallace about Matthew’s book, or may have alerted them to its existence via their citations and/or via the publishers’ adverts. Darwin also boasted in several letters that he had widely-read the “agricultural and horticultural” literature (Eiseley 1959, Dower 2009, see also my “Variations (1868)” entry), so he may have chanced across Matthew’s book by himself. Even it this didn’t happen, Darwin and Wallace may have been “contaminated” by the “Matthewisms” used by others, and thus they could no longer be regarded as independent ‘originators’ (Sutton 2014).
- If influence via Matthew’s book alone could be proved, then Matthew’s failure to further publicise his ideas would be irrelevant.
- The minority view questions both Darwin’s and Wallace’s integrity. For example, they would argue that Darwin deliberately “stitched up” Wallace over the way his famous “Ternate” paper describing macroevolution by natural selection was published jointly in 1858 with hastily put-together excerpts of Darwin’s previous writings (Davies 2008), that Darwin ordered his own copy of Matthew’s book with improbable speed (Dower 2009), and also that Darwin deliberately strove to belittle Matthew’s standing (Dempster 1996). They would also argue that Wallace having his ‘eureka’ moment while bed-ridden with malaria sounds medically implausible (Dempster 2005).
- A devious, duplicitous Darwin (see point 3) could have concocted or doctored his notebooks to conceal his influence by Matthew’s book, although he was unable to completely cover his tracks (see point 5). There is also the possibility that he read Matthew’s book early in his career, perhaps even in the 12 months between the publication of Matthew’s book and his departure on board The Beagle, and that he then subsequently forgot he’d done so, but subconsciously sublimated and assimilated his ideas (the “cryptomnesia” hypothesis).
- Matthew’s book refers in places to domesticated species being more varied than natural ones. Darwin makes a similar point, specifically with reference to nursery-grown trees, in his unpublished 1844 essay. Then in his later 1868 published work The Variation of Animals and Plants under Domestication Darwin makes the same point and this time specifically cites Matthew. Loren Eiseley (1959) first drew attention to this evidence, and also to the fact that Matthew used the phrase “natural process of selection” in his book, which could then have been the inspiration for Darwin’s term “natural selection”. Sutton (2014) also draws attention to pages of Darwin’s notebooks which refer to “fruit trees” and indeed specifically to “golden pippens”, and Sutton notes that the “scarlet golden pippin” is specifically mentioned by Matthew in an 1829 article published in the Memoirs of the Caledonian Horticultural Society, a journal which Darwin also listed in his “Books to be Read” notebook so this article may have been read by Darwin. Hugh Dower (2009) points out that Darwin’s unpublished manuscript Natural Selection, written in the mid 1850’s, contains a reference to two species of oak (Quercus robur and Q. sessiliflora) and the intermediate forms that exist between them, and the same observation also appears in Matthew’s book (p.32).
Some further points to consider
A detailed point-by-point examination of all the arguments above is beyond the scope of this article. I consider the Darwin/Matthew similarity in the concept of increased variety under domestication in my “Variation (1868)” entry, I consider Darwin’s reference to “fruit trees” and “Golden pippens” in my “Matthew (1829)” entry, and I consider the speed with which Darwin obtained his copy of Matthew’s book in my “@Bookseller (9 April 1860)” entry. I will, however, make some general points below, before closing with a more detailed critique of Mike Sutton’s “knowledge contamination” hypothesis.
- If people did tell Darwin and/or Wallace about Matthew’s book, or were aware of his ideas on macroevolution by natural selection, why didn’t these same people complain when both Darwin and Wallace claimed to have come up with their idea independently? Special pleading is required to explain this discrepancy.
- All the evidence is circumstantial. There is no “smoking gun” here. All the evidence could be explained under an alternative scenario whereby those who read Matthew’s book mistook his evolutionary views as a rehash of Lamarck and others, and so did not consider them original. Matthew was not cited enough times, nor in the right context, to reach the attention of Darwin or Wallace. Similarities in ideas (for example regarding the increase in variety of species under domestication) could be attributed to coincidence and to a “convergent evolution” towards the same underlying ideas. Likewise, “selection” was a widely used term among breeders, and could explain the similarity in the phrases “natural process of selection” and “natural selection”.
- A large amount of weak evidence is very difficult to evaluate. Life is random and messy. There is a huge amount of information to sift through (especially for Darwin, where so many records, letters, notebooks, etc. exist). Under such situations, one can often extract a large amount of weak evidence for all sorts of contrasting and mutually exclusive scenarios. By concentrating on just one set of weak evidence (e.g. for plagiarism or for a duplicitous Darwin) one may fall foul of “selection bias” – i.e. finding that which you set out to find, and overestimating the significance of the data. To make an analogy, imagine someone had access to your lifelong volume of letters, emails and texts. That person then extracted only those messages where you had in some way been untruthful, and then used these to construct a hypothesis that you were a devious, duplicitous person. This would be an example of “selection bias”.
There are different hypotheses with different implications:
- It is useful to separate the “plagiarism hypothesis” (that Darwin and/or Wallace read Matthew’s book and obtained their idea of macroevolution by natural selection from it) from the “knowledge contamination” hypothesis (that Darwin and/or Wallace obtained ideas from Matthew’s book indirectly via third parties, and used these to help formulate their own ideas). I consider the “knowledge contamination” hypothesis in more detail below.
- It is also useful to separate the “plagiarism hypothesis” into two types – a “deliberate plagiarism” hypothesis in which Darwin and/or Wallace knowingly stole from Matthew’s book and lied about it, and a “cryptomnesia plagiarism” hypothesis in which Darwin and/or Wallace read Matthew’s book, forgot they did so, but kept the information sub-conciously (note I’m defining plagiarism broadly here, to include inadvertent copying). I think either version of the “plagiarism hypothesis” would be enough to strip Darwin and/or Wallace of the right to be called independent originators of the idea of macroevolution by natural selection, but the hypotheses clearly have different implications for the moral standing of Darwin and/or Wallace.
- The “Matthew Plagiarism” hypothesis is very different to the “Blyth Plagiarism” hypothesis. The “Blyth Plagiarism” hypothesis was first put forward by Loren Eiseley (1959), and proposes that Darwin obtained many of his case examples and ideas regarding natural selection from papers written in the mid 1830’s by Edward Blyth, but without properly accrediting him. This is different because (a) Darwin never denied knowledge of Blyth’s work, and indeed he did cite Blyth in his later publications, so what we have here is failure of attribution rather than specific denial of prior knowledge (as in the case of Matthew); (b) Blyth wrote about natural selection, but only as a stabilizing force that kept separately-created species to their intended form – Blyth was an anti-evolutionist. Thus even if Darwin did get some ideas from Blyth (and Eiseley’s case for this is quite compelling) this would not strip Darwin of his right to be thought of as an originator of the idea of macroevolution by natural selection.
Mike Sutton’s “knowledge contamination” hypothesis
Mike Sutton’s “knowledge contamination” hypothesis proposes that, even if Darwin and Wallace did not directly read or learn about Matthew’s book, they were nevertheless likely to have been “contaminated” by Matthew’s ideas via the transmission of his ideas into publications which Darwin and Wallace did read, or into the minds of colleagues with whom they consulted. For example (among the many given in Sutton (2014), “List 2”), the phrase “long continued selection” appears in Matthew’s book, then in a book by David Low and then in Darwin’s Origin of Species. The same is true of Matthew’s idea of increased variation in domesticated species, which again appears in a book by Low (On Landed Property, and the Economy of Estates (1844), p.546) and then in Darwin’s 1844 unpublished essay (see discussion above). Assuming that Low got these ideas from Matthew, and assuming that Darwin then got them from Low, this would be an example of “knowledge contamination” that, according to Sutton, would invalidate Darwin’s claim to be an independent originator of the concept of macroevolution by natural selection. My position on this hypothesis is as follows:
- Mike Sutton divides his list of potential “knowledge contaminators” into two sets. “List 1” contains people known or almost certainly known to have read Matthew’s book, while “List 2” contains people that Sutton proposes as people who possibly read Matthew’s book because they use a distinctive “Matthewism” phrase that first appears in Matthew’s book. Regarding “List 1”, the challenge is to find ideas that we think uniquely came from Matthew’s book and which were definitively passed on to Darwin and Wallace. This challenge is made more difficult by the fact that, to our knowledge, only one of the people in “List 1” ever made any direct critique regarding Matthew’s ideas on evolution and natural selection (Loudon, in his 1832 review). Regarding “List 2”, there is an additional challenge, which is to establish that replication of a “Matthewism” phrase does indeed constitute good evidence that the person did so because they had read Matthew’s book. This is considered further in the next two points.
- It is difficult to prove that a “Matthewism” phrase like “long continued selection” is indeed original to Matthew. Leaving aside the issue that not all books, and certainly not all journals and newspapers, are available in online repositories like Google Books, the current quality of image-to-text conversion in these repositories is quite poor, and this means that a phrase like “long continued selection” may exist in a prior publication but appear in Google Books as “log continued selection” or some other mistake.
- It is difficult to prove that a “Matthewism” phrase like “long continued selection” appears in a later work specifically because the author read Matthew’s book, rather than being replicated merely by chance. The volume of text being searched in Google Books is enormous, making chance replications more likely.
- It is difficult to prove that a “Matthew idea” like the increased variation seen in domesticated trees species was so special that no-one else could have thought of it, without having to read Matthew’s book.
- Even if one could prove that an idea or “Matthewism” was transmitted to Darwin and/or Wallace, this would not invalidate their claim to have also originated the idea of macroevolution by natural selection. Given that both “macroevolution” and “natural selection” were ideas known prior to Matthew, Darwin and Wallace, the only claim to originality that any of them could make was the act of bringing those two ideas together. Provided Darwin and/or Wallace did not obtain the whole idea directly from Matthew, they can still lay claim to that act of originality. True, if Matthew had provided them indirectly with an important component, that would have made Darwin’s and/or Wallace’s act of originality easier. Thus one must consider not only the question of whether any knowledge contamination took place at all, but also whether the knowledge that may have been transferred was important. Clearly the transfer of a simple three-word phrase like “long continued selection” would not count as important, whereas the transfer of an idea like “increased variation in domesticated species” would count as more important.
[Mike Weale, first published 2015-03-21, last revised 2015-06-01]
Reply by Mike Sutton
Mike Weale very kindly asked me to reply. I am delighted to be given the opportunity to do so. My reply can be found on my PatrickMatthew website: http://patrickmatthew.com/sutton%27s%20position%20paper.html. I have also considered the question of “Matthew’s Influence” in more depth on my BestThinking blogsite: https://www.bestthinking.com/thinkers/science/social_sciences/sociology/mike-sutton?tab=blog&blogpostid=22693.
My work on this topic continues with investigations of the correspondence of those newly discovered to have cited Matthew pre-1858. In this second wave of research, further new independently verifiable hard-fact discoveries have been made (not all by me) since the publication of my book ‘Nullius in Verba: Darwin’s greatest secret.’ I expect to update my position paper with such further new data, some of which was unearthed only recently. Unfortunately, for what are effectively commercial and honourable/contractual reasons, I am not yet in a position to release the latest information into the public domain.
Mike Sutton, 1st June 2015