Metaphor and representation in early modern cell doctrine.
Jameson B Bell
ABD in German Literature and Culture
The Pennsylvania State University, University Park, PA, USA
This article reviews the current secondary literature on the Renaissance ventricular doctrines and offers a new approach to this often overlooked period in the history of the brain. By exploring an alternate episteme of metaphor, this article argues that understanding a Renaissance mode of knowing that transferred meaning between material and idea, rather than judging the accuracy of the represented image, proves fruitful in approaching often contradictory and confusing images and texts of the brain and its functions. Thus, the late 16th century shift to a more accurate representation and material definition of cerebral anatomy can be understood in a larger, more culturally determined constellation of changes where knowledge was suspended between an idea of the object and its materiality.
Keywords: brain, ventricular theory, epistemology, images, Renaissance, metaphor
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This article revisits a difficult episode in the history of the brain as an object, otherwise known as the ventricular doctrine, cell doctrine or theory. The Renaissance hand-drawn and printed brain images, accompanied by often contradictory commentary, have been interpreted by contemporary scholars as crude and transitional, while those closer to modern visual and linguistic standards are defined as accurate, better, and more truthful (1, 2, 3). This paper will focus specifically on the 16th century and argue that contemporary emphasis on visual knowledge was only slowly becoming a priority and negative adjectives describing the accuracy of these images are not germane to the historical discourse. After a brief definition of the ventricular theory and a review of current scholarship, I will interpret 16th century brain images and accompanying text as an example of a distinctive episteme that used metaphor rather than representation to convey meaning about the brain.
The use of metaphor provides an alternative narrative to this period in the history of the brain-as-object and offers a glimpse into how Renaissance intellectual culture experienced the world differently. Using metaphor to approach both everyday and scientific speech, as well as objects and knowledge formation, has been previously discussed in various forms (4, 5, 6, 7). My approach does not attempt to uncover the underlying psychological structures of late Renaissance thought, but utilizes metaphor as a descriptive tool with which individuals transferred meaning between two ontologically distinct domains. As will become clear, this mode of knowing allowed the schematic and diagrammatic images of beliefs about the mind to be meaningfully transferred to the material of the brain itself. In other words, as briefly indicated (separately) by Bruyn and Hagner, the ventricular theory imposed a diagram of the idea of the brain’s function on the material of the brain, creating the possibility of seeing the idea rather than the material (8, 9). The tension between a culture’s constructed epistemic values and its representations has been well documented (7, 10, 11). Understanding an episteme that maintained and transferred meaning between both the idea and the material may prove a useful tool for contemporary historians to approach these brain images and their seemingly foreign presentations.
What were the Ventricular Theories?
The emphasis on plurality of views is essential to understanding the various approaches to the idea of the brain taken by individuals prior to the 17th century. In its most basic form, the cerebral ventricles were deemed the dwelling of the “inner senses” that received, organized, and stored information that came from the “outer senses.” Simon Kemp provides a cohesive analysis of the definitions and applications of this distinction between inner and outer senses by medieval European and Arab scholars (12, 13). In short, information or species of perception from the five external senses of touch, taste, hearing, sight, and smell are first received in the anterior ventricle, then transferred, organized and stored in the central and posterior ventricles. Though the actual number of inner senses varied, the language of movement and location from “front to back” were common in defining the interaction of the brain’s ventricular anatomy and physiology. In various manuscripts and texts, the anterior ventricle could be divided into “imagination” and “judgment,” the central ventricle into “reason” and “estimation” (occasionally the sensus communis was located in either the anterior or central ventricles) and the posterior ventricle into “active remembrance” and “passive memory.” Occasionally, the fourth posterior ventricle was cited as part of the mental process and the passage or duct between the ventricles was also named vermis or “snake/worm” (1,2,3,8,9). Sensible species were taken into the anterior ventricle, reason arranged the mental images in a coherent order in the centrally located ventricle and subsequently sent the mental images to memory located in the posterior ventricle for future use.
From the diverse collection of the above-described brain functions, various images through the late medieval and Renaissance periods superimposed schematic and functional diagrams on a human (almost exclusively male) head (Figure 1) (14). Christopher Green argues that late medieval scholars created the complete cell theory used during the European Renaissance, as there exists no documentation that a comprehensive localization theory existed until at least the 9th century (15).
Many of the late medieval and Renaissance images follow the same schematic structure of circles or geometrical shapes superimposed on a standardized head, mirroring both the geometrical similarity of the most perfect shape and Christian theology of the tripartite nature of the divine (13, 14). Names of the various inner senses are printed in the circles or outside the image with a line pointing to their proper location. Green argues that late medieval scholars, in their philological approach to ancient authorities, pieced together a ventricular theory found only in partial and infrequent form in Aristotle, Plato, Herophilus, Galen, Nemesis, Augustine, Avicenna, Aquinas, Roger Bacon, and Albertus Magnus, among others. The discrepancy in various theories was thus more a textual and translation problem than a crisis with the theory itself (2).
That there were ventricular localization theories provides one example of the challenges of negotiating a transfer of meaning from one domain to another. What is the “ideal” to which the material corresponds? To which authority does one turn? The shift to a rationally constructed visual representation was seen as a means to mediate this problem of multiple or even infinite ideals; accurate images provided confidence in knowledge that was communicable and objective. Yet however neutral representations seem, Daston and Galison have recently presented a nuanced critique of this practice of valuing objectivity: even seemingly natural images are based on epistemic virtues that shift over time (9).
In the next section I will review current secondary literature on ventricular theories, followed by a contextual approach that situates them in a different set of practices and beliefs, one with its own means of negotiating the difficulties of understanding and representing the mind and brain.
Brief Discussion of Secondary Literature
Simon Kemp’s relatively well-known texts provide an outline for medieval psychology as an introduction for modern scholars to understand the structure of the ventricular localization theory (12, 13). Though he does not speculate how classical, Arabic, and medieval scholars influenced Renaissance theories of the brain (and there are some questions as to the chronology of a complete ventricular theory), Kemp’s discussion of debates surrounding intromission or extramission theories is necessary to grasp the cognitive work performed by the inner senses in later theories. Extramission can be defined as the individual’s active influence on the external world. All objects radiate species, thus perception (mainly visual) meets the object external to the brain. Intromission occurs when an object’s species are received and interpreted inside the body. The intromission theory, which required a locus or chamber for the sensible data in the body, gained dominance in the later medieval period. Thus when the brain became the dominant location of the soul—as opposed to the cardio-centric interpretation of Empedocles, Aristotle and Tertullian (9)—the majority of scholars located the inner senses and the internal interaction of the mind with the material world within the cerebral ventricles (12, 13).
Other more linear brain histories (2, 3, 16) provide longer narratives of the development of the brain throughout Western history but only briefly explain the ventricular theory on the way to the more accessible, modern brain. Following Kemp, E. R. Harvey provides the most comprehensive study of the inner senses (17), yet Christopher Green’s recent criticism offers new insights into translation difficulties that medieval and Renaissance scholars encountered in creating a complete ventricular doctrine. His language-based approach argues that inaccurate translations of ancient texts influenced the late development as well as the diverse natures of the ventricular theories (15). On this matter, Tessman et. al. and Kusukawa and Maclean propose that the printing press (c. 1455) was extremely influential because it provided a means to communicate standard ideas and images across Europe, allowing for a more unified approach not just to cerebral anatomy but to all disciplines (18, 19).
Clarke and Dewhurst offer the most complete collection of ancient and early modern brain images, now in its second edition (2). By focusing on the history of localization of brain functions, Clarke and Dewhurst use much of their text commenting on the influence of ventricular localization on post-16th century extra-ventricular localization theories. Though the collection of images is vast and extremely useful, commentary on early modern brain images is sparse and denigrating through the rhetoric of improvement toward modern representation techniques (now even more prominent with the addition of a posthumous final chapter on computerized tomography). However, these commentaries provide opportunities to ask critical questions about the role of history in engaging both the contemporary fascination with the brain as well as promoting an understanding of this alternative theory that lasted in various forms for the majority of a millennium.
Other studies provide cultural contexts to the discussion of the changing social climate that influenced cerebral anatomy in the Renaissance. Linear perspective, and aesthetic refinement of vision (19, 20, 21, 22), secularization of illness and ritualized dissection practices (23, 24, 25, 26), new views on memory (27, 28), changing dissection techniques (29,30), a developing international community and standardized texts (16, 24, 25, 26, 30, 31), and the lasting effects of the theory of bodily humors (32) are all emphasized on the way to creating a “modern body” and thus a more “modern brain.” These articles and monographs provide insightful and important fragments of the story, yet a culturally specific history of the Renaissance cerebral localization theory has yet to be pieced together. The underlying assumption of progress, comparing empirical discoveries and accumulating knowledge was both unfamiliar to the Renaissance scholars and extraneous to the discussion of the brain until the end of the 16th century. Renaissance humanists believed knowing nature was participating in divine knowledge, which cannot be directly translated into later practices that collected, assembled, represented and produced facts in ever-narrowing disciplines.
As I will demonstrate in the next section, understanding the importance of the ventricular theory within its own epistemological vocabulary and presentation provides helpful tools for scholars to critically engage a foreign object. The questions Renaissance scholars asked did have satisfactory answers. Understanding this question/answer process will help to explain both their “foreignness” as well as our own culturally situated habits of perception. The 16th century was a time where the aforementioned influences converged: new print technologies allowed individuals all over Europe to see and discuss the same text and image; linear perspective as well as an emphasis on the geometrical structure of perception allowed three dimensional images to be printed in two dimensional space; fresh approaches to comparative translation provided new insights into the fallibility of ancient authorities; and secularization of knowledge and an increase in dissections were each part of a transformative constellation that created new questions for the brain that ventricular theories could not answer.
Knowledge and the Brain in 16th Century Europe: Material and/or Idea.
A current anatomy and physiology text and a standard neurophysiology text tout one of their most compelling attributes as having accurate and realistic images (33, 34). This statement and ocular practice is a condensed form of a modern visual maxim: images must represent something as accurately as they are visibly known. Through this precise visual language, the simple act of seeing an object or image becomes a form of knowing. Representational codes are very easy to detect as either accurate or inaccurate, proportional or not, true or false; the trained modern eye knows. However, for the history of scientific objects, this was not always the case (10). In order to approach images and descriptions of the brain up to and during the 16th century, one can assume that knowing and seeing were separate activities. If vision was indeed separate from rational knowledge, one may ask the question, what would be the purpose of drawing and printing an accurate image of an object as it is seen when the meaning was only given as it is known? The very structure of the various ventricular doctrines attests to the separation of perception (sense) from knowledge (reason) and requires a means to connect the idea to the material: metaphor.
A metaphor can be defined as a transfer of meaning from one domain to another where the essential qualities of one object or idea are attributed to another (6). For example, if an object is composed of two domains—material and form (also called idea, design, or telos)— only the most important features of the material will be necessary to access this idea. If the material object is understood correctly, individuals can create the idea or purpose of the object under investigation.
Conclusion: From Metaphor to Representation
The end of the Renaissance corresponded in part to the fall of this episteme of the metaphor. The separate activities of seeing and knowing, what Martensen calls “likeness” and “presence,” slowly lost importance in late Renaissance body knowledge as accurate images became essential to medical and scientific practices (11). Active investigations combined with precise scientific and medical representation became the norm: one could know the dissected body and brain as an object not an idea. Printed images began to emphasize this visuality and representations appeared as the object would appear to the rationally seeing eye. In accurate representations, the metaphoric domain of idea and material are collapsed so that meaning is found in reasoned perception of the truthful image of the material object itself (Figure 3) (10).
For these images to succeed, the use of visual “tricks” became essential: three-dimensional representations of the brain that began in the 16th century were presented in structured space along with new alphabetic organization of names of gross anatomical fragments that emphasize the materiality of the object.