The Expression of the Emotions in Man and Animals
The Expression of the Emotions in Man and Animals is Charles Darwin's third major work of evolutionary theory, following On The Origin of Species (1859) and The Descent of Man (1871). Originally intended as a section of The Descent of Man, it was published separately in 1872 and concerns the biological aspects of emotional life. In this book, Darwin sets out some early ideas about behavioural genetics, and explores the origins of such human characteristics as the lifting of the eyebrows in moments of surprise and the mental confusion which typically accompanies blushing. A German translation of The Expression appeared in 1872; Dutch and French versions followed in 1873 and 1874. A second edition of the book, with only minor alterations, was published in 1890.
|Subject||Evolutionary theory, human behaviour|
Before Darwin, human emotional life had posed problems to the western philosophical categories of mind and body. Darwin's interest can be traced to his time as a medical student and the 1824 publication of Sir Charles Bell's Anatomy and Philosophy of Expression which argued for a spiritual dimension to the subject. In contrast, Darwin's biological approach links mental states to the coordination of movement, and allows cultural factors only an auxiliary role in the shaping of expression. This biological emphasis leads to an appreciation of the universal nature of expression, with its implication of a single origin for the entire human species; and Darwin points to the significance of emotional communication with children in their psychological development. Darwin sought out the opinions of some leading British psychiatrists, notably James Crichton-Browne, in the preparation of the book which forms his main contribution to psychology.
Amongst the innovations with this book are Darwin's circulation of a questionnaire (probably inspired by his cousin, Francis Galton) in his preparatory research; simple psychology experiments  on emotional recognition with his friends and family; and (borrowing from Duchenne de Boulogne, a physician at the Salpêtrière) the use of photographs in his presentation of scientific information. Publisher John Murray warned Darwin that including the photographs would "poke a hole in the profits" of the book; and The Expression of the Emotions is an important landmark in the history of book illustration.
The book's development: biographical aspectsEdit
Background: In the weeks before Queen Victoria's coronation in 1838, Charles Darwin sought medical advice on his mysterious physical symptoms, and then travelled to Scotland for a period of rest and a "geologizing expedition" – but actually spent some of his time re-exploring the old haunts of his undergraduate days. On the day of the coronation, 28 June 1838, Darwin was in Edinburgh. A few weeks later, he opened a private notebook with philosophical and psychological speculation – the M Notebook – and, over the next three months, filled it with his thoughts about possible interactions of hereditary factors with the mental and behavioural aspects of human and animal life.
The critical importance of the M Notebook has usually been viewed in its relationship to Darwin's conception of natural selection as the central mechanism of evolutionary development, which he probably grasped some time around September 1838. These notes have a tentative and fragmented quality, especially in Darwin's descriptions of conversation with his father (a successful doctor with a special interest in psychiatric problems) about recurring patterns of behaviour in successive generations of his patients' families. Darwin was anxious about the materialistic drift in his thinking – and of the disrepute which this could attract in early Victorian England – at the time, he was mentally preparing for marriage with his cousin Emma Wedgwood who held firm Christian beliefs. On 21 September 1838, after his return to England, Darwin recorded a confused and disturbing dream in which he was involved in a public execution where the corpse came to life and claimed to have faced death like a hero. In summary: Darwin put together the central features of his evolutionary theory at the same time that he was considering a scientific understanding of human behaviour and family life – and he was in some emotional turmoil. A discussion of the significance of Darwin's early notebooks can be found in Paul H. Barrett's Metaphysics, Materialism and the Evolution of Mind – Early Writings of Charles Darwin (1980).
Mental qualities are determined by the size, form and constitution of the brain: and these are transmitted by hereditary descent.— George Combe, (1828) The Constitution of Man
One is tempted to believe phrenologists are right about habitual exercise of the mind altering form of head, and thus these qualities become hereditary....When a man says I will improve my powers of imagination, and does so, – is not this free will ?...— Charles Darwin, (1838) The M Notebook
To avoid stating how far I believe in Materialism, say only that emotions, instincts, degrees of talent, which are hereditary are so because brain of child resembles parent stock – (and phrenologists state that brain alters)....— Charles Darwin, (1838) The M Notebook
Development of the Text 1866 - 1872: Very little of Darwin's turmoil surfaced in On the Origin of Species in 1859, although Chapter 7 contains a mildly expressed argument on instinctive behaviour. In the public management of his evolutionary theory, Darwin understood that its relevance to human emotional life could draw a hostile response. Nevertheless, while preparing the text of The Variation of Animals and Plants under Domestication in 1866, Darwin took the decision to publish a book on human ancestry, sexual selection and emotional life. After his initial correspondence with the psychiatrist James Crichton-Browne Darwin set aside his material concerning emotional expression in order to complete The Descent of Man, which covered human ancestry and sexual selection. Darwin concluded work on The Descent of Man on 15 January 1871. Two days later, he started on The Expression of the Emotions and, on 22 August 1872, he finished work on the proofs. In this book, Darwin brings his evolutionary theory into close approximation with behavioural science, although many Darwin scholars have remarked on a kind of spectral Lamarckism haunting the text of the Emotions.
Universal Nature of Expression: Darwin notes the universal nature of expressions in the book, writing: "the young and the old of widely different races, both with man and animals, express the same state of mind by the same movements."
This connection of mental states to the neurological organization of movement (as the words motive and emotion suggest) is central to Darwin's understanding of emotion. Darwin himself displayed many biographical links between his psychological life and locomotion, taking long, solitary walks around Shrewsbury after his mother's death in 1817, in his seashore rambles near Edinburgh with the Lamarckian evolutionist Robert Edmond Grant in 1826/1827, and in the laying out of the sandwalk, his "thinking path", at Down House in Kent in 1846. These aspects of Darwin's personal life are discussed in John Bowlby's (1990) psychoanalytic biography of Darwin.
Darwin emphasises a shared human and animal ancestry in sharp contrast to the arguments deployed in Charles Bell's Anatomy and Philosophy of Expression (1824). Bell claimed that the facial muscles were divinely designed in order to express uniquely human feelings. Eager to stress the differences between human and animal communication, Bell wrote: "Expression is to the passions as language is to thought." In The Expression, Darwin reformulates the issues at play, writing: "The force of language is much aided by the expressive movements of the face and body" - hinting at a neurological intimacy of language with psychomotor function (body language),and underscoring the social value of expression.
Darwin's Sources on Emotional Expression: Darwin had listened to a discussion about emotional expression at the Plinian Society in December 1826 when he was a medical student at Edinburgh University. This had been prompted by the publication of Sir Charles Bell's Anatomy and Philosophy of Expression; and in his presentation, the phrenologist William A.F. Browne (in a spirited account of Robert Grant's Lamarckist philosophy) ridiculed Bell's theological explanations, pointing instead to the striking similarities of human and animal biology. The meeting then ended in uproar. Forty-five years later, Darwin revisits these arguments and recruits Duchenne's (1862) unmasking of the facial mechanisms, shifting the argument from philosophical speculation to scientific discourse. Darwin's response to Bell's natural theology is discussed by Lucy Hartley (2001).
In the composition of the book, Darwin drew on worldwide responses to his questionnaire (circulated in the early months of 1867) concerning emotional expression in different ethnic groups; on anthropological memories from his time on HMS Beagle; on conversations with livestock breeders and pigeon fanciers; on observations on his infant son William Erasmus Darwin (A Biographical Sketch of an Infant), on his family's dogs and cats, and on the orangutans at London Zoo; on simple psychology experiments with members of his family concerning the recognition of emotional expression; on the neurological insights of Duchenne de Boulogne, a physician at the Salpêtrière asylum in Paris; on hundreds of photographs of actors, babies and children; and on descriptions of psychiatric patients in the West Riding Pauper Lunatic Asylum at Wakefield in West Yorkshire. Darwin corresponded intensively with James Crichton-Browne, the son of the phrenologist William A. F. Browne and now the medical director of the Wakefield asylum. At the time, Crichton-Browne was preparing his extremely influential West Riding Lunatic Asylum Medical Reports, and Darwin remarked to him that The Expression "should be called by Darwin and Browne". Darwin also drew on his personal experience of the symptoms of bereavement and studied the text of Henry Maudsley's 1870 Gulstonian lectures on Body and Mind. He considered other approaches to the study of emotions, including their depiction in the arts – discussed by the actor Henry Siddons in his Practical Illustrations of Rhetorical Gesture and Action (1807) and by the anatomist Robert Knox in his Manual of Artistic Anatomy (1852) – but abandoned them as unreliable, although the text of The Expression is littered with quotations from Shakespeare.
Darwin opens the book with three chapters on "the general principles of expression", introducing the rather Lamarckist phrase serviceable associated habits. With this phrase, Darwin seeks to describe the initially voluntary actions which come together to constitute the complex expressions of emotion. He then invokes a principle of antithesis, through which opposite states of mind induce directly opposing movements. Finally, he discusses a direct action of the nervous system, in which an overflow of emotion is widely discharged, producing more generally expressed emotions.
This is followed by a section (three more chapters) on modes of emotional expression peculiar to particular species, including man. He then moves on to the main argument with his characteristic approach of astonishingly widespread and detailed observations. Chapter 7 discusses "low spirits", including anxiety, grief, dejection and despair; and the contrasting Chapter 8 "high spirits" with joy, love, tender feelings and devotion. Subsequent chapters include considerations of "reflection and meditation" (associated with "ill-temper", sulkiness and determination), Chapter 10 on hatred and anger, Chapter 11 on "disdain, contempt, disgust, guilt, pride, helplessness, patience and affirmation" and Chapter 12 on "surprise, astonishment, fear and horror". In Chapter 13, Darwin discusses complex emotional states including self-attention, shame, shyness, modesty and blushing.
Darwin closes the book with Chapter 14 in which he recapitulates his main argument: he shows how human emotions link mental states with bodily movement, and are genetically determined, deriving from purposeful animal actions. He comments on the implications of the book: a single origin for the entire human species, with universal human expressions; and he stresses the social value of expression, citing the emotional communication between mother and child.
This was one of the first books to be illustrated with photographs – with seven heliotype plates – and the publisher John Murray warned that this "would poke a [terrible] hole in the profits".
The published book assembled illustrations rather like a Victorian family album, with engravings of the Darwin family's domestic pets by the zoological illustrator T. W. Wood as well as work by the artists Briton Rivière, Joseph Wolf and A.D. May. It also included portraits by the Swedish photographer Oscar Rejlander (1813–1875), anatomical diagrams by Sir Charles Bell (1774–1842) and Friedrich Henle (1809–1885), as well as illustrational quotations from the Mécanisme de la physionomie humaine (1862) by the French neurologist Duchenne de Boulogne (1806–1875). As a result of his domestic psychology experiments, Darwin reduced the number of commonly observed emotions from Duchenne's calculation of more than sixty facial expressions, to just six "core" expressions: anger, fear, surprise, disgust, happiness and sadness.
Darwin received dozens of photographs of psychiatric patients from James Crichton-Browne, but included in the book only one engraving (photoengraved by James Davis Cooper) based on these illustrations – sent on 6 June 1870 (along with Darwin's copy of Duchenne's Mécanisme) (Darwin Correspondence Project: Letter 7220). This was Figure 19, page 296 – and showed a patient (Crichton-Browne reported) under the care of Dr James Gilchrist at the Southern Counties Asylum (of Scotland), the public wing of the Crichton Royal in Dumfries.
I have been making immense use almost every day of your manuscript – the book ought to be called by Darwin and Browne....— Charles Darwin to James Crichton Browne
This section needs expansion. You can help by adding to it. (April 2013)
The review in the January 1873 Quarterly Journal of Science concluded that "although some parts are a little tedious, from the amount of minute detail required, there is throughout so much of acute observation and amusing anecdote as to render it perhaps more attractive to general readers than any of Mr. Darwin's previous work".
Eric Korn, in the London Review of Books, describes how the book was claimed, and he argues subverted, by Margaret Mead and her "sympathisers", and then presented afresh by Paul Ekman. Ekman had collected pro-Darwin, anti-Mead evidence, Korn wrote, for the universality of human facial expression of emotions. Darwin, suggests Korn, avoided unsettling the Victorian public by arguing that humans had "animal traits", and instead charmed them by telling stories of "human traits in animals", thus avoiding too much explicit talk of natural selection at work. Darwin preferred to leave the evolutionary implications hanging. Korn points out that the book has never been out of print since 1872, calling into question Ekman's talk of "Darwin's lost masterpiece".
The "Editor's notes" at the "Mead Project source page" on the book comment that
Darwin's book ... is among the most enduring contributions from 19th century psychology. The ideas expressed in its pages have persisted, for better or worse, down through the present, in one form or another. Although premised on an unsupportable interpretation of the nature of "expression," it is this idea that permeates the majority of work on emotional experience within psychology... Dewey's critique of Darwin's principles provides no small part of the foundations on which functionalist psychology is built. Similarly, the work plays a very large part in George Herbert Mead's discussion of the formation of significant symbols, as outlined in the early chapters of Mind, Self and Society. As Dewey notes, the arguments presented by Darwin may be wrong, but they are compelling.
Darwin concluded work on the book with a sense of relief. The proofs, tackled by his daughter Henrietta ("Ettie") and son Leo, required a major revision which made Darwin "sick of the subject and myself, and the world".
It quickly sold around 7,000 copies and was widely praised as a charming and accessible introduction to Darwin's evolutionary theories.
The lavish style of biological illustration was followed in work on animal locomotion by photographer Eadweard Muybridge (1830–1904)(leading to cinematography), and by the Scottish naturalist James Bell Pettigrew (1832–1908); in the extensively (and controversially) illustrated works of the evolutionary biologist Ernst Haeckel; and – to a lesser extent – in D'Arcy Thompson's On Growth and Form (1917).
Darwin's ideas were followed up in William James' What Is An Emotion ? (1884); and, in the James-Lange theory of emotions, James develops Darwin's emphasis on the physical aspects, including the visceral (autonomically mediated) components of emotion. In Walter Cannon's Bodily Changes in Pain, Hunger, Fear and Rage (1915), Cannon introduces the famous phrase fight or flight response, formulating emotions in terms of strategies for interpersonal behaviour. More recent psychological theories of emotion have been set out in the Papez-Maclean hypothesis and the Two factor theory of emotion.
On 24 January 1895, James Crichton-Browne delivered a notable lecture in Dumfries, Scotland On Emotional Expression, presenting some of his reservations about Darwin's views. Crichton-Browne argued for a greater role for the higher cortical centres in the regulation of the emotional response, and touches on the theme of gender differences in emotional expression, anticipating the approach of sociologist Norbert Elias in The Civilizing Process. In 1905, Sir Arthur Mitchell, a psychiatrist who had served as William A.F. Browne's deputy in the Scottish Lunacy Commission, published About Dreaming, Laughing and Blushing, bridging some of Darwin's concerns with those of psychoanalysis. In 2003, the New York Academy of Sciences published Emotions Inside Out: 130 Years after Darwin's The Expression of the Emotions in Man and Animals, a compendium of 37 papers with current research on the subject.
"George Herbert was wrong when he said that man was all symmetry; it was woman to whom that remark applied....evolution is still going on, and the faces of men and women still altering, for the better, every day. The emotions are less violently expressed....our ancestors gave vent to their feelings in a way that we would be ashamed of, and their range of feeling seems to have been in some degree more limited. The language of the countenance, like that of the tongue, has been enriched in the process of the suns...."— James Crichton-Browne, On Emotional Expression, being The Presidential Address, Dumfriesshire and Galloway Natural History and Antiquarian Society (Thursday, 24th January 1895)
"All these sensations and innervations belong to the field of The Expression of the Emotions, which, as Darwin (1872) has taught us, consists of actions which originally had a meaning and served a purpose. These may now for the most part have become so much weakened that the expression of them in words seems to us to be only a figurative picture of them, whereas in all probability the description was once meant literally; and hysteria is right in restoring the original meaning of the words...."— Josef Breuer and Sigmund Freud, Studies on Hysteria (1895)
Freud's early publications on the symptoms of hysteria (with his influential concept of unconscious emotional conflict) acknowledged debts to Darwin's work on emotional expression. Darwin's impact on psychoanalysis is discussed in detail by Lucille Ritvo. Constitutional (psychosomatic) theories of personality were later elaborated by Paul Schilder (1886 - 1940) with his notion of the body image, by the psychiatrist Ernst Kretschmer and in the (now largely discredited) somato-typology of W H Sheldon (1898 - 1977). The biology of the human emotions was further explored by Desmond Morris in his (richly illustrated) popular scientific book Manwatching.
- see, for example, Sartre, Jean-Paul (1971) Sketch for a Theory of the Emotions (with a Preface by Mary Warnock) London: Methuen & Co., originally published (1939) as Esquisse d'une théorie des émotions.
- Young, Robert M. (1970) Mind, Brain and Adaptation in the Nineteenth Century Oxford: Clarendon Press; reprinted (1990) in History of Neuroscience Series New York: OUP
- Darwin Charles, Ekman Paul, Prodger Phillip (1998) The Expression of the Emotions in Man and Animals, 3rd edn, London: Harper Collins.
- Snyder, Peter J. et al (2010) Charles Darwin's Emotional Expression "Experiment" and His Contribution to Modern Neuropharmacology Journal of the History of Neurosciences, 19:2, pp 158 - 170
- Barrett 1980
- Barrett 1980, p. xviii
- Ospovat, Dov (1981) The Development of Darwin's Theory Cambridge: Cambridge University Press
- Mayr, Ernst (1991) One Long Argument: Charles Darwin and the genesis of modern evolutionary thought Cambridge, Mass: Harvard University Press
- Barrett 1980, pp. 6–37
- Browne, E. Janet (1995) Charles Darwin: Voyaging, London: Jonathan Cape, pp 383 – 384.
- Barrett 1980, p. xix
- Pearn, Alison M. (2010) "This Excellent Observer..." : the Correspondence between Charles Darwin and James Crichton-Browne, 1869 – 75, History of Psychiatry, 21, 160 – 175
- see, for example, Paul Ekman's textual commentary in Darwin, Ekman, Prodger (1998) The Expression of the Emotions, 3rd edition, London: HarperCollins, pages 45 and 54; and see also "Introduction" by Steven Pinker (2008) The Expression of the Emotions London: The Folio Society, pp. xix - xxii.
- Desmond, Adrian (1982) Archetypes and Ancestors: Palaeontology in Victorian London 1850 – 1875 Chicago: Chicago University of Chicago Press, pp 116 – 121
- Desmond, Adrian (1989) The Politics of Evolution: Morphology, Medicine and Reform in Radical London Chicago: University of Chicago Press
- Stott, Rebecca (2003) Darwin and the Barnacle London: Faber and Faber
- Boulter, Michael (2006) Darwin's Garden: Down House and the Origin of Species London: Constable
- Bowlby, John (1990) Charles Darwin, A Biography London: Hutchinson.
- Bell, Charles (1806) Essays on the Anatomy of Expression in Painting London:
- Bell, Charles (1824) Essays on the Anatomy and Philosophy of Expression London: John Murray
- Bowlby, pp. 6 – 14
- Hartley, Lucy (2001) Physiognomy and the Meaning of Expression in Nineteenth Century Culture Cambridge University Press
- Walmsley, Tom (1993) Psychiatry in Descent: Darwin and the Brownes, Psychiatric Bulletin, 17, 748 - 751
- Maudsley, Henry (1870) Body And Mind: The Gulstonian Lectures for 1870 London: Macmillan and Co.
- Phillip Prodger Curator of Photography Peabody Essex Museum (29 August 2009). Darwin's Camera : Art and Photography in the Theory of Evolution. Oxford University Press. pp. 109–. ISBN 978-0-19-972230-3. Retrieved 4 August 2013.
Heliotype was a new photomechanical method of reproduction invented by the photographer Ernest Edwards (1837–1903), for whom Darwin had sat for a portrait in 1868. Although he had no experience in photographic publishing, Darwin suggested this new technique to John Murray. ... heliotype reduced the cost of production considerably, enabling Darwin to afford the unprecedented number of photographs appearing in Expression.
- Charles Darwin (9 April 1998). The Expression of the Emotions in Man and Animals. Oxford University Press. pp. 401–. ISBN 978-0-19-977197-4. Retrieved 4 August 2013.
Darwin's English publisher, John Murray, was at first opposed to the idea of using photographs to illustrate the book. He advised Darwin that the inclusion of photographs would make Expression a money-losing proposition
- Duchenne (de Boulogne), G.-B., (1990) The Mechanism of Human Facial Expression by Guillaume-Benjamin (Amand) Duchenne de Boulogne edited and translated by R. Andrew Cuthbertson, Cambridge University Press and Paris: Éditions de la Maison des Sciences de L'Homme, originally published (1862) Paris: Éditions Jules Renouard, Libraire
- Anon (January 1873). "Darwin's "The Expression of the Emotions in Man and Animals"". Quarterly Journal of Science: 113–118.
- Korn, Eric (November 1998). "How far down the dusky bosom?". London Review of Books. 20 (23): 23–24.
- c/o Ward, Lloyd Gordon (2007). "A Mead Project Source Page: The Expression of the Emotions in Man and Animal". The Mead Project, Brock University, Ontario, Canada. Retrieved 3 April 2013.
- Frederick Burkhardt; Sydney Smith; David Kohn; William Montgomery (10 March 1994). A Calendar of the Correspondence of Charles Darwin, 1821–1882. Cambridge University Press. pp. 366–. ISBN 978-0-521-43423-2.
To [Leonard Darwin] 29 July  [Down] CD cannot improve style [of Expression] without great changes. 'I am sick of the subject, and myself, and the world'.
- Keith Francis (2007). Charles Darwin and The Origin of Species. Greenwood Publishing Group. pp. 20–. ISBN 978-0-313-31748-4.
1872 19 February: Sixth edition of The Origin of Species is published (3,000 copies printed).  26 November: The Expression of the Emotions in Man and Animals is published (7,000 copies printed; 5,267 sold). 1874 Second edition of The ...
- Black, J (Jun 2002), "Darwin in the world of emotions" (Free full text), Journal of the Royal Society of Medicine, 95 (6): 311–3, doi:10.1258/jrsm.95.6.311, ISSN 0141-0768, PMC , PMID 12042386
- Prodger, Phillip (2009) Darwin's Camera: Art and Photography in the Theory of Evolution Oxford University Press
- Muybridge, Eadweard (1984) The Male and Female Figure in Motion: 60 classic photographic sequences New York: Dover Publications
- Prodger, Phillip (2003) Time Stands Still: Muybridge and the instantaneous photography movement The Iris and B. Gerald Cantor Center for the Visual Arts, Stanford University, in association with Oxford University Press
- Pettigrew, James Bell (1874) Animal Locomotion, or, Walking, Swimming and Flying, with a dissertation on Aeronautics New York: D. Appleton and Co.
- Pettigrew, James Bell (1908) Design in Nature, 3 vols, London: Longman
- Smith, Jonathan (2006) Charles Darwin and Victorian Visual Culture Cambridge University Press, especially pp. 179 – 243
- Cannon, Walter B. (1915) Bodily Changes in Pain, Hunger, Fear and Rage – An Account of Recent Researches into the Function of Emotional Excitement New York: D. Appleton and Co.
- Barrett, Lisa Feldman (2017) How Emotions Are Made: The Secret Life of The Brain New York: Houghton, Mifflin, Harcourt and London: Macmillan
- [Crichton-Browne, James] (1895) Conversazione, - and the Presidential Address – "On Emotional Expression", Transactions and the Journal of Proceedings of the Dumfriesshire and Galloway Natural History and Antiquarian Society, Series II, 11, pp 72–77, Dumfries: The Courier and Herald Offices
- Mitchell, Sir Arthur (1905) About Dreaming, Laughing and Blushing Edinburgh and London: William Green and Sons. Mitchell (pp. 153 - 157) provides a useful bibliography on emotional expression at the dawn of the twentieth century.
- Sulloway, Frank J. (1979) Freud, Biologist of the Mind: Beyond the Psychoanalytic Legend London: Burnett Books/Andre Deutsch
- Ritvo, Lucille B. (1990) Darwin's Influence on Freud: A Tale of Two Sciences New Haven and London: Yale University Press
- Schilder, Paul (1950) The Image and Appearance of the Human Body: Studies in the Constructive Energies of the Psyche New York: International Universities Press
- Morris, Desmond (1978) Manwatching: A Field Guide To Human Behaviour London: Triad Panther.
|Wikimedia Commons has media related to The Expression of the Emotions in Man and Animals.|
- Darwin, Charles (1872), The Expression of the Emotions in Man and Animals, London: John Murray.
- Freeman, R. B. (1977), The Works of Charles Darwin: An Annotated Bibliographical Handlist (2nd ed.), Folkstone: Dawson.
- Ekman, Paul (editor) (2003), Emotions Inside Out: 130 Years after Darwin's The Expression of the Emotions in Man and Animals (1st ed.), New York: New York Academy of Sciences .
Free e-book versions: