Philosophical Perspectives on the Engineering Approach in Biology

Living Machines?

Sune Holm, Maria Serban, Sune Holm, Maria Serban

• Publisher: Routledge
• Year: 2020
• ISBN:
  9781351212229
• Edition: 1
• Topic: Filosofia
• Subtopic: Filosofia etica e morale

Philosophical Perspectives on the Engineering Approach in Biology provides a philosophical examination of what has been called the most powerful metaphor in biology: The machine metaphor. The chapters collected in this volume discuss the idea that living systems can be understood through the lens of engineering methods and machine metaphors from both historical, theoretical, and practical perspectives.

In their contributions the authors examine questions about scientific explanation and methodology, the interrelationship between science and engineering, and the impact that the use of engineering metaphors in science may have for bioethics and science communication, such as the worry that its wide application reinforces public misconceptions of the nature of new biotechnology and biological life. The book also contains an introduction that describes the rise of the machine analogy and the many ways in which it plays a central role in fundamental debates about e.g. design, adaptation, and reductionism in the philosophy of biology.

The book will be useful as a core reading for professionals as well as graduate and undergraduate students in courses of philosophy of science and for life scientists taking courses in philosophy of science and bioethics.

Part 1
Theoretical issues

1 Restless machines

Jessica Riskin

On a Sunday evening in November 1868, the English naturalist Thomas Henry Huxley, professor of natural history at the Royal School of Mines and of anatomy and physiology at the Royal College of Surgeons in London, friend and defender of Charles Darwin, made a joke about which people continue to chuckle almost a century and a half later, and whose humor captures what this chapter is about.

Huxley had been invited to Edinburgh by a renegade clergyman, the Reverend James Cranbook, to inaugurate a new series of “lectures on non-theological topics.” Huxley chose as his nontheological topic “protoplasm” or, as he defined it for the uninitiated, “the physical basis of life.” His main point was simple: we ought, he said, to be able to understand the properties of protoplasm, including its quite extraordinary property of being alive, simply in terms of its component parts, without invoking any special something, any force or power called “vitality” (Huxley 1869, 129).¹

After all, Huxley pointed out – and here’s the joke – water has extraordinary properties, too, but we know that it is made of hydrogen and oxygen combined in certain proportions within a range of temperatures, and we do not “assume that something called ‘aquosity’ entered into and took possession of the oxide of hydrogen … then guided the aqueous particles to their places.” To be sure, Huxley continued, we do not presently understand just how water’s properties follow from its composition any more than we understand how protoplasm can be alive, yet “we live in the hope and in the faith that … we shall by-and-by be able to see our way as clearly from the constituents of water to the properties of water, as we are now able to deduce the operations of a watch from the form of its parts and the manner in which they are put together” (ibid., 139–140).

Huxley’s lecture was a huge hit. When it appeared in print as the lead article in the Fortnightly Review the following February, several editions of the issue sold out immediately, and John Morley, the review’s editor, reckoned no article for a generation had “excited so profound a sensation” (Morley 1917, 90). The quip about aquosity continues almost a century and a half later to reappear regularly in biology textbooks and works of popular science.² A successful joke condenses layers of implicit argument and assumption into a very few words. In violation of the principle that one should never explain a joke (and in confirmation of the general feeling that the simpler the joke, the longer the explanation), this chapter offers an extended explanation of Huxley’s quip. In particular, it addresses three aspects.

First, the joke assumes a founding principle of modern science; namely, that a scientific explanation must not attribute will or agency to natural phenomena: no active powers such as “aquosity” that “take possession” of things and “guide” them along their way. This rule also disallows, for example, explaining the falling weight driving a clock by saying that the weight wants to move closer to the center of the earth, or explaining the expansion of steam in a steam engine by saying that the steam intends to move upward toward the sky.

Second, Huxley’s joke plays upon the uncertainties and hesitations involved in extending this principle of banning agency to the explanation of living phenomena, in affirming that “vitality” is no more useful or scientific a concept than “aquosity.”

Finally, in place of explanations invoking mysterious powers such as “aquosity,” Huxley recommended mechanist scientific explanations that took as their model of nature the workings of an artificial machine such as a watch.

This chapter briefly examines the origins and history of the principle Huxley popularized, banning agency from science, and this principle’s accompanying clockwork model of nature, in particular as these apply to the science of living things. In so doing, we will also encounter a tradition of dissenters who would have rejected Huxley’s punchline since they embraced the opposite principle that agency is an essential and ineradicable part of nature.

To trace the origins of modern scientific mechanism, we begin in a time and place that will perhaps be unexpected: the churches and cathedrals of late medieval and Renaissance Europe. These were thrumming with lifelike machines: automaton angels that sang and prayed, horrible devils that rolled their eyes and flailed their wings and tails, saints making ecclesiastical gestures, Christs grimacing on the cross, Virgins ascending Heavenward, and even the Holy Father himself making holy motions.

Outside of churches and cathedrals, the early modern European landscape was similarly bustling with androids and automaton animals. Sixteenth- and seventeenth-century Europeans with the means to do so established theme parks of automatic, mostly hydraulic, amusements on the grounds of their palaces and estates.

These machines engaged playfully with visitors, spraying them with water or flour or ash, hiding from or pursuing them, making faces and singing songs. Mechanism in the context of these machines did not signify the qualities it later assumed: rote, regular, constrained behavior. Instead, it signified something more like their opposites: unexpectedness, surprising behavior, responsiveness. Therefore, to propose, as the French philosopher René Descartes momentously did during the 1630s, that animal and human bodies were essentially machines did not mean that living things were passive or rote, but quite the contrary. Descartes described hydraulic grottoes in the French royal gardens in Saint-Germain-en-Laye, where automata enacted scenes from Greek mythology, in which these machines responded to spectators, fleeing from them, menacing them, engaging playfully and variously with their human visitors.

During the course of the 17th century, however, the idea of animal and human machinery narrowed into something passive, constrained, rote, without agency, really antithetical to life, mind, and spirit. For convenience, let us call the new mechanism of the later 17th century “brute mechanism.” Brute mechanism actually developed, in large part, in the service of a new theological program of the 17th century – namely, arguments from design – finding evidence of a rational Designer in the rational design of his artifact, nature. Arguments from design evacuated all perception and agency to a location decisively outside the material world, leaving a fundamentally passive machinery behind. The modern scientific paradigm of nature as a complex, rational, and passive clockwork arrangement thus relied in its first instance upon a theological principle – a supernatural, rational designer-god – and mechanist scientific ideas continue to bear the imprint of this theology. For example, the theological principle of design informed the first notion of physiological adaptation during the 17th century, the idea that living beings are ideally suited to their environments, and this original theology lives on in deep disguise in current evolutionary biology.

Meanwhile, although brute mechanist natural theologians were evacuating perception and agency from nature, there were still those who struggled to hold matter, feeling, and will together to keep the machinery alive. These holdouts accordingly had something very different in mind when they talked about the “clockwork cosmos” or the “animal-machine”; let us call it “active mechanism.” Active mechanism – a mechanism in which spirit and agency constituted parts of the very works – is often hard to discern through the distorting acoustics of the latter 18th and 19th centuries.

Consider how William Harvey, author of the hydraulic pump model of the heart, invoked automata in his account of the process of animal generation.

Scrutinizing the development of a chick embryo, Harvey observed that a great many things happened in a certain order “in the same way as we see one wheel moving another in automata, and other pieces of mechanism.” But, Harvey said, the parts of the mechanism were not moving, as some natural philosophers claimed, in the sense of changing their places. Rather, the parts were remaining in place but transforming “in hardness, softness, colour, &ce” (Harvey 1847b, 417).³ It was a mechanism made of changing parts.

This was an idea to which Harvey regularly returned. Animals, he thought, were like automata whose parts were perpetually transforming: expanding and contracting in response to heat and cold, imagination and sensation and ideas (Harvey 1959). The image of a mechanism of changing parts resonates with another in Harvey’s treatise on the motion of the heart in which Harvey likened the heart to a “piece of machinery in which one wheel gives motion to another, yet all the wheels seem to move simultaneously” (Harvey 1847a, 31). Geared mechanisms represented constellations of motions that seemed at once sequential and simultaneous, a congress of mutual causes and effects.⁴

The first appearance of life itself, as Harvey described it, seemed to happen both all at once and as a sequence of events. Harvey wrote about seeing the chick first as a “little cloud,” and then,

In the midst of the cloudlet in question there was a bloody point so small it disappeared during the contraction and escaped the sight, but in relaxation it reappeared again, red and like the point of a pin; so that betwixt the visible and the invisible, betwixt being and not being, as it were, it gave by its pulses a kind of representation of the commencement of life.

(ibid.)

A gathering cloud and, in its midst, a barely perceptible movement between being and not being. Harvey again cited both clockwork and firearms as models to depict a defining feature of this cloudy pulse that was life: the fusion of causation and simultaneity.

Elsewhere, Harvey invoked an analogy that would become commonplace by the end of the century: the relationship between an animal body and a church organ.

He suggested that the muscles worked like “play on the organ, virginals.” But what Harvey meant by this comparison is striking. Later, people tended to mean a complex system of interacting parts when they compared living bodies to organs. Harvey, though, meant that the muscles performed their actions by “harmony and rhythm,” a kind of “silent music” (Harvey 1959, 145–147).

These examples of ways in which Harvey invoked artificial mechanisms indicate a problem with classifying him either as a “mechanist” or otherwise; namely, that the meaning of “mechanism” was in flux. Harvey told his students at the College of Physicians that anatomy was a “mechanical” subject (Harvey 1961, 22). But what did he mean?

Well, one thing he meant was that there was no need to invoke ethereal or celestial substances in explaining physiological phenomena because the mundane elements, he said, transcended their own limits when they acted. The “air and water, the winds and the ocean” could “waft navies to either India and round this globe.” The terrestrial elements could “grind, bake, dig, pump, saw timber, sustain fire, support some things, overwhelm others.” Fire could cook, heat, soften, harden, melt, sublime, transform, set in motion, and produce iron itself. The compass pointing north, the clock indicating the hours, all were accomplished simply by means of the ordinary elements, each of which, Harvey said, “exceeded its own proper powers in action” (Harvey 1847b, 508–509). So his idea is not reductive but really the reverse – elevative – matter rising to new powers in action.

Similarly, Harvey elsewhere defined “mechanics” as “that which overcomes things by which Nature is overcome.” His examples were things having “little power of movement” in themselves that were nonetheless able to move great weights, such as a pulley. Mechanics, understood in this way, included natural phenomena that overcame the usual course of nature: Harvey again mentioned the muscles. So to say that the muscles worked mechanically in this instance meant that the muscles, like artificial devices such as a pulley, overcame the usual course of nature and moved great weights without themselves being weighty (Harvey 1959, 127). Again, here is a form of mechanism that is really the opposite of reductive.

Another way to get at what “mechanism” meant to Harvey is to look at what posed problems for a mechanist physiology and what sorts of solutions Harvey proposed. One problem he identified, for example, was action at a distance. He was working from the Aristotelian view that embryos arose from a kind of contagion, “a vital virus” with which the sperm infected the egg.⁵ And Harvey arrived at the problem of action at a distance. After the initial moment of contact, once the contaminating element had disappeared and become “a nonentity,” he wondered, how did the process continue? “[H]ow, I ask, does a nonentity act? How does a thing which is not in contact fashion another thing like itself?” (Harvey 1847b, 359–360). Aristotle, Harvey pointed out, had invoked automata, automatic puppets, to explain this. He had suggested that the initial contact at conception set off a succession of linked motions that constituted the development of the embryo (Aristotle, Generation of Animals, Bk 2). Harvey rejected this explanation (ibid., 345–346).⁶

In its place, he proposed a different analogy: one between the uterus and ...

Table of contents

• Cover
• Half Title
• Series
• Title
• Copyright
• Contents
• List of contributors
• Acknowledgments
• Introduction
• Part 1 Theoretical issues
• Part 2 Methodological issues
• Part 3 Societal issues
• Editors’ postscript
• Index