Here’s one I made earlier: the development and communication of ancient medical scientific theories through analogy and demonstration Keith Stewart Department of Classics and Ancient History University of Exeter July 2014

Contents Timeline Metaphorical Language in the Ancient World Galenic and Hippocratic Analogies Practical Demonstrations

Timeline 600 BCAD 200 HIPPOCRATIC CORPUS GALEN SocratesAlexander the GreatAugustus PRESOCRATICS Thales Parmenides Empedocles Herophilus of Chalcedon Erasistratus of Ceos Marcus Aurelius Plato Aristotle STOICS EPICUREANS Celsus

Metaphorical Language (1) A metaphor is the application of a word that belongs to another thing: either from genus to species, species to genus, species to species, or by analogy. (Aristotle, Poetics, 1457b7-10; translation by Innes) I call “by analogy” cases where b is to a as d is to c: one will speak of d instead of b, or b instead of d. (Aristotle, Poetics, 1457b16-18; translation by Innes) … but much the greatest asset is a capacity for metaphor. This alone cannot be acquired from another, and is a sign of natural gifts: because to use metaphor well is to discern similarities. (Aristotle, Poetics, 1459a5-8; translation by Innes)

Metaphorical Language (2) Aristotle ridicules the Presocratic philosopher Empedocles, if people think that he ‘has made an intelligible statement when he says that the sea is the sweat of the earth.’ Aristotle’s objection is that ‘such a statement is perhaps satisfactory in poetry, for metaphor is a poetic device, but it does not advance our knowledge of nature.’ (Aristotle, Meteorology, 357a24-28)

Metaphorical Language (3) Galen is in general agreement with Aristotle and sets out his own criteria about how scientific concepts should be communicated: … the chief merit of language is clearness, and we know that nothing detracts so much from this as do unfamiliar terms, … (Galen, On the Natural Faculties, II.1-2 K; translation by Brock) … we must distinguish and explain clearly the various terms … and to what things we apply them; and this will prove to be not merely an explanation of terms but at the same time a demonstration of the effects of nature. ( Galen, On the Natural Faculties, II.2 K; translation by Brock)

Galenic Analogies (1) For blood, like milk, appears to be some one thing; but reason teaches us that it is not one thing, just as milk is not. One part of milk is extremely serous and thin, another is extremely cheese-like and thick. As long as they were mixed together they produced milk midway between cheese and whey; but when separated they exhibited their own proper form and revealed the nature of milk, that it was in fact not just one thing but a composite of opposite and differing things. As then in milk there is whey and there is cheese, so in blood there is a kind of serum analogous to the whey in milk, and there are dregs, as it were, and lees analogous to the cheese. (Galen, On the Elements According to Hippocrates, K; Translation, De Lacy).

Galenic Analogies (2) Besides, if the kidneys are like sieves, and readily let the thinner serous portion [of the blood] through, then the whole of the blood contained in the vena cava must go to them, just as the whole of the wine is thrown into the filters. Further, the example of milk being made into cheese will show clearly what I mean. For this, too, although it is all thrown into the wicker strainers, does not all percolate through; such part of it as is too fine in proportion to the width of the meshes passes downwards, and this is called whey; the remaining thick portion which is destined to become cheese cannot get down, since the pores of the strainers will not admit it. Thus it is that, if the blood-serum has similarly to percolate through the kidneys, the whole of the blood must come to them, and not merely one part of it. (Galen, On the Natural Faculties, II.58 K; translation by Brock)

Hippocratic Analogies (1) This phenomenon resembles what the Scythians do with mare’s milk; for they pour milk into a hollow wooden container and shake it; as the milk is shaken it foams and separates, and the fatty component, which they call butter, rises to the top because it is light. The heavy and thick component stays near the bottom, and this they separate and dry; when it has coagulated and become dry, they call it “hippace”; in the middle is the milk’s whey. Similarly, when all the moisture in a human being’s body is stirred up, everything in him separates for the reasons I have described: on top will be what comes from bile, since this is lightest, second what comes from blood, third what comes from the phlegm, and the heaviest of these moistures is the watery component. (Hippocratic Corpus, Diseases IV, L, translation by Potter).

Hippocratic Analogies (2) This reaction is like what happens to milk: when someone pours fig juice into milk, coldness comes over the milk which thickens it and at the same time produces whey around what has thickened. In this same way, in a person, too, when morbid coldness arises, moisture condenses and becomes thick: and around the water itself, as much other moisture as is present in excess in the body will be in contact with it. (Hippocratic Corpus, Diseases IV, 590 L, translation by Potter)

Galenic Demonstration And I shall state in what way they [the parts of the body] gain this extension in every direction, first giving an illustration for the sake of clearness. Children take the bladders of pigs, fill them with air and then rub them on ashes near the fire, so as to warm, but not to injure them. This is a common game in the district of Ionia … When it appears to them fairly well distended, they again blow air into it and expand it further; then they rub it again. … Now, clearly, … the more the interior cavity of the bladder increases in size, the thinner, necessarily, does its substance become. But if the children were able to bring nourishment to this thin part, then they would make the bladder big in the same way that Nature does. (Galen, On the Natural Faculties, II.17 K; translation by Brock)

Hippocratic Demonstration What I have called “springs” always pass material on to the body when they are full, whereas when they are empty, they draw off material from it, and the cavity does just the same. For it is as if someone were to pour water into three or more copper vessels, and, setting them together in a very level place, arrange them as evenly as possible, fit pipes into openings in them, and pour water gently into one of the vessels until they were all full of water; that is, the water would flow from the first copper vessels into the other ones, until they were full. When the vessels are all full, if someone removes water from any one of them, the other vessels will give water back that will flow into that one, so that all the vessels will be emptied in the same way they were filled. In the body it is the same; for as foods and drinks come into the cavity, the body fills itself up by drawing moisture out of the cavity, and so too do the springs; but when the cavity is emptied, moisture flows back into it, just as when one of the bronze vessels receives water from the others. (Hippocratic Corpus, Diseases IV, (VII L))

Conclusion There can be an educational function for the use of metaphorical language to communicate scientific ideas. Clearly see that across 600 years of the history of medical writing that metaphorical language plays an important role in scientific communication. It is not just theoretical comparisons that are important, but also physical examples that people could witness for themselves or even make in their own homes. This takes the understanding of scientific ideas out of the lecture rooms or dusty books (scrolls) and directly into people’s imagination.

Bibliography Brock, A. J. (trans.) (2006), Galen: On the Natural Faculties, Loeb, Cambridge, Massachusetts. De Lacy, P. (trans.) (1996), Galen: On the Elements According to Hippocrates, Berlin. Halliwell, S., Fyfe, W. H., Russell, D., Innes, D. C. and Rhys Roberts, W. (trans.) (1995), Aristotle: Poetics, Longinus: On the Sublime, Demetrius: On Style, Loeb, Cambridge Massachusetts. Lee, H. D. P. (trans.) (1989), Aristotle: Meteorologica, Loeb, Cambridge, Massachusetts. Potter, P. (trans.) (2012), Hippocrates: Volume X, Loeb, Cambridge, Massachusetts.