- 1 The title of this article has been inspired by a recent book that deals with musica mundana and hu (...)
1For the last several decades I have been exploring the place of musical thought in early modern intellectual and scientific culture from around 1500 to around 1750 (e.g. Gouk 1980, 2000, 2014).1 To clarify, I am not directly concerned with actual music but rather with ideas about music or ideas expressed through music during this critical period in British and European history (Gouk 1999a). My explorations have followed two distinct pathways, although these routes have intersected with each other from time to time. The first route has been determined by posing the following questions: how did intellectuals think in general about music’s defining attributes and functions, and in particular how did they explain its effects? What if any significant changes in thinking about music took place between 1500 and 1750? These broad questions naturally encourage an interdisciplinary approach to the problem at both a primary and secondary level, since the evidence they need to interrogate spreads across fields such as acoustics, mathematics, music theory, natural and moral philosophy, medicine and also religion, magic, poetry and literature.
2The second route for my research has been guided by a more abstract consideration of the role of musical models in scientific and medical thinking during this 250-year span (Gouk 1999b). The early modern era was an exciting if turbulent period of Western history that according to academic convention embraces the late Renaissance, the Reformation, the seventeenth-century Scientific Revolution – which for music and the arts is also identified as the baroque era – and finally the early Enlightenment or beginning of the classical period. By adopting this long-term view one of the aims of my research has been to uncover how certain musical models (for example, the human body being imagined as a musical instrument, or fundamental particles of matter behaving like musical strings) played a key role in philosophical and scientific thought over this extended period (e.g. Gouk 2002, 2013).
3Intellectual historians now take for granted that the artificial divisions I have presented here more or less coincide with significant long-term shifts in philosophical thinking about the cosmos and humanity’s place within it. Overall, one of the most dramatic transformations must surely be the eventual widespread acceptance of a heliocentric model of the universe at the expense of the traditional geocentric view. This new paradigm presupposed that all bodies from planets to people were governed by the same natural laws, as persuasively demonstrated in Isaac Newton’s Philosophiae Naturalis Principia Mathematica (1687), or Mathematical Principles of Natural Philosophy. Another striking change in thinking that has been noted is the apparent decline of magical beliefs in European polite society around this time and the concomitant rise of “scientific” thought (Thomas 1980).
- 2 It is important to note that by the early seventeenth century music had essentially dropped out of (...)
4All this is now grist to the mill for cultural historians and historians of science, but another transformation that is less well understood by this particular research community is the developments in art and music that took place successively in the Renaissance, baroque and classical eras. For example, one of these developments is the emergence of experimental forms of instrumental music that were equal to, and in some cases even independent from, the voice (Gouk 2012, Cypess 2016). Spada Lionello’s The Concert depicts some musicians c.1617 playing a mixed “concert” or “consort” of instruments made up of a lute, violin and potentially guitar, and reading music from a part book. The fashion for playing consort music was widespread and was notably taken up by the English court in the early seventeenth century. My claim is that it is essential for historians of science to acknowledge such important trends in musical practice because of the long-term impact that they had on theoretical ideas about the nature of music and the laws governing its composition. Indeed, as is shown in the case of Britain, these new musical theories eventually had an impact on scientific theory more generally, not least because music was part of the university curriculum as a branch of mathematics and was also defined as one of the seven liberal arts (Gouk 1999a: 66–88).2
5This mention of the curriculum and the classification of music as both a mathematical science and a liberal art allows me at this point appropriately to reflect on the significance of the wording of my title. Musica humana (human music, especially the harmony between body and soul) and musica mundana or musica universalis (world/universal music) are concepts which go back at least to the sixth century AD, to the works of the philosopher and music theorist Boethius, and were still in use in the early seventeenth century (Moyer 1992, Hauge 2011). In brief, they derive from the Neoplatonic philosophical tradition and are predicated on the understanding that the universe is alive and that it is bound together both by a network of harmonic proportions linking man, the microcosm, and the cosmos, or the macrocosm, and also by a fine ethereal substance (spiritus) that fills the interstices between them. The dictum “as above, so below” applied to all these connections, which had as their basis the Pythagorean proportions of the musical scale, simple mathematical ratios that were immanent in the cosmos. A third kind of music that fitted into this overall paradigm was musica instrumentalis, or what we now think of as “real” or instrumental music, not excluding voices. Again, the basis of this concept was the Pythagorean musical ratios, the music in this case being created by the power of numbers to constitute sounding intervals (Prins 2015).
6There is more to be said about music and Neoplatonic philosophy, but for the time being it is enough to note that it offered a clear blueprint for certain types of magic, the exercize of extraordinary powers that were not explicitly reliant on the forbidden assistance of demons but rather used human skills and technologies. The most notable of these practices was the domain of “natural”, or “spiritual” magic, which purportedly relied on the harnessing of impersonal but also insensible or occult (i.e. hidden) powers in nature by means of devices in order to bring about marvellous effects. This was an aspect of natural magic that was taken over by Francis Bacon (1561–1626) in his proposal for a new science of acoustics (Gouk 1999a: 95–111; Tomlinson 1993). As well as exploiting the harmonious relations or “sympathy” between macrocosm and microcosm, the magus also depended on his musical skills to alter in specific ways the nature of the spiritus, the extremely active and rarefied substance that Neoplatonists believed filled the animated cosmos linking the heavenly and earthly realms and which acted as a channel for astrological influences. Indeed, the magus’s power also further extended to the human spirit or spiritus which, like its heavenly counterpart, linked body and soul, and acted as the medium for all cognitive, sensory and motor functions, including the manipulation of the passions through the power of music. This spirit, sometimes called the sensitive soul (by Thomas Willis [1621–1675], for example), was none other than the hot animal spirits that according to conventional medical teaching were distilled from the blood, stored in the brain and flowed through the nerves acting as the agent of the rational mind. In other words, the twin concepts of musica mundana and musica humana provided a means for thinking about the universe as an integrated whole well before the beginning of the eighteenth century. These musico-philosophical concepts also recognized the human body and soul as part of this integrated system, linked to it by means of the nerves and animal spirits, a conception that predated the mechanical philosophy’s insistence that the same natural laws operated both in the heavens and earthly realms.
7Before considering specifically English interpretations of the mechanical philosophy, especially as they emerged in the later seventeenth century and became established in the eighteenth, it is important to recognize that these developed chiefly in response to Descartes’s seminal works Traité du monde et de la lumière, Traité de l’homme and Les passions de l’âme, which collectively emphasized that both the universe and man worked like clockwork automata or pieces of hydraulic machinery, their fabric being made up of inert particles of matter set in motion by external stimuli (Gouk 2013). Indeed, Cartesian physics reduced all physical phenomena to the principles of matter in motion, including the manifestation of human passions and their physiological effects as well as the motions of the planets. As is well known, Descartes (1596–1650) adopted a dualistic position regarding the immaterial soul and its relationship to the body, the actions of the soul itself being capable of altering a person’s behaviour or temperament through the agency of the nerves, which he conceived of as comprising hollow tubes, with the animal spirits flowing along the thin fibres inside them. Through their movement the spirits serve a twofold function, first to enable the soul or mind to interact with the body, and second to inflate the muscles to which the spirits are carried by the nerves (Kassler 1995: 44; Palisca 2000).
8Descartes’s influence in England, especially after his death, was such that it became normal for natural philosophers to adopt instrumental/mechanical models of bodily actions. However, it is striking to note that these models departed from Descartes’s in that they mostly did not conceive of matter as being wholly passive, moving only when struck by motion from beyond the realm of motion itself. An alternative, “magical” view was that matter could also contain within itself active principles that could account for particular sensible and insensible phenomena (Henry 1986, 1989). This position is exemplified in the thinking of Robert Hooke (1635–1703), who from 1662 was the Royal Society’s Curator of Experiments. More comprehensively than any other intellectual figure in this period, Hooke held a musical, or harmonic, conception of the cosmos that not only echoed the Boethian concepts of musica mundana and humana, but also revealed a debt to the associated tradition of natural magic, with its emphasis on spiritus (Gouk 1980, 1999a, Chap. 6). One of the most likely influences on Hooke’s model was that of the English physician Robert Fludd (1574–1637), whose Utriusque cosmi … historia (History of the Macrocosm and Microcosm) (1617–19) contains remarkable visualizations of the musical proportions governing the cosmos and man.
9Robert Hooke postulated that the universe consists of matter that is in constant vibrative motion, being constituted of differently sized particles that either cohere with each other at the same pitch or frequency (i.e. according to the principle of sympathy or congruity), or are repulsed because of being a different frequency (i.e. antipathy or incongruity). Indeed, Hooke conceptualized matter as if it were made up of tiny musical strings, the “pitch” of each being determined by the properties of matter or substance, figure or shape and body or bulk, in the way that the length, tension and “bigness” of a string determines its frequency. These latter observations were based on Hooke’s knowledge of Mersenne’s Laws, which had been established by the French Minim friar around 1635 (Cohen 1984: 97–114; Gouk 1999a: 170–178). At the same time, Hooke suggested that the sense organs, particularly those of hearing and sight, are constructed according to similar principles that can explain how these senses work. Thus the ear is designed so that the eardrum vibrates in sympathy with the motions it receives from sounding bodies via the sonorous medium. All musical tones have to be kept within the physiological limits of the ear, since very high notes force the eardrum to be overstretched and likely to be damaged, like a string that has been stretched to breaking point.
10From this mechanical, naturalistic explanation for pleasing and unpleasing sounds Hooke deduced that the aesthetic pleasure we derive from music is caused by variety: in the “consecution of tones”, in the duration of notes, in the timbres of different instruments, but above all “in the agreement of several tones sounding together, such as is that of unisons, eights, 5ths, 4ths & 3rds &c – that is, harmony”. Harmony affords the acoustic faculty “the most ravishing pleasure & delight of all” (Gouk 1980: 605). This is because listening to music involves ratiocination, the operation of the mind “wherein the use and benefit of geometricall knowledge doth most eminently show itself” (Gouk 1980: 605).
11In order to explain why musical harmony is perceived as pleasurable by the soul, Hooke invokes two general principles. The first of these is that nature acts regularly and geometrically in insensible as well as sensible motions, the argument being that both the invisible motions of the mind and those of visible bodies obey the same (musical) laws. The second principle is that “God by nature has framed our bodys also according to geometricall rules” (Kassler & Oldroyd 1983: 586). With a clear allusion to musica humana Hooke observes that men “have a body harmoniously constructed and an harmonious soule to be affected thereby” (Kassler & Oldroyd 1983: 586). He also notes that the discovery of these principles is attributed to Pythagoras and other ancient philosophers, which may be why Pythagoras and Plato “asserted the soule to be made of numbers”, speculation that led to the axiom that “God doth always act geometrically, that is, by due proportions of number weight & measure” (Kassler & Oldroyd 1983: 588).
12Of course, it is music itself (musica instrumentalis) that provides Hooke with the most compelling demonstrations of these two fundamental principles. The ether or ethers thought to fill the universe could be conceptualized in terms of invisible vibrating particles that obey demonstrable musical laws. Hooke developed a number of hypotheses about the vibrative nature of matter that drew on this fundamental insight. For example, he thought that the attractive force of gravity could be explained in terms of a short and quick vibrative motion initially generated by the earth and transmitted to the fluid of the universe, which vibrates “every way in Orbem from and towards the centre, in lines radiating from the same” (Hooke 1705: 184). He also thought that the soul itself might be a central point within the brain, which he identifies as the chief instrument of the soul and the internal organ of memory and perception. If made of the right kind of matter he thought that the brain would be capable not only of receiving impressions from all the senses but also of transmitting vibrations outwards to accomplish the soul’s cognitive tasks. A distinctive feature of Hooke’s speculations about incessantly vibrating matter was that he saw the principles of congruity and incongruity as being firmly grounded in experiment. It is likely that the acoustical and musical experiments he conducted at the Royal Society were attempts to prove his theory of vibrating matter.
13Compelling as Hooke’s theory of a vibrative musical universe might be to modern readers, most of his ideas on the subject were never published, nor were they pulled together anywhere to create a satisfactory whole. However, some of his insights were taken forward by no less a figure than Isaac Newton (1642–1727), whose early investigations into the nature of light and colours (communicated to the Royal Society in 1672) were roundly criticized by Hooke. In brief, Newton had demonstrated the composite nature of white light by his prism experiments, and theorized that colours had a corpuscular foundation, his aim at this stage being simply to describe the behaviour of coloured light in terms of momentum change (i.e. the particles are like billiard balls). Hooke’s criticism was that the corpuscular theory of light was inadequate to explain the periodic nature of colours, and that in fact colours and musical tones were related by their vibrational and periodic nature (Gouk 1999a: 237–246).
14Although Newton never acknowledged Hooke, from 1672 onwards he explored the analogy between colours and musical harmony and eventually came up with the spectrum scale divided into seven colours equivalent to the seven notes of the musical scale. This comparison between the periodicity of light and sound was underpinned by Newton’s aethereal explanation of both colour perception and music perception. In the first of these, light particles emitted from light sources moved at different speeds through an all-pervasive and highly active aether that filled the interstices of air, a movement that set up periodic vibrations in the aether which were then transmitted to the eye. In the second place, musical sound was similarly communicated to the ear by the vibrating aether, but this was set in motion by the sounding body itself moving the air periodically (i.e. Newton did not think sound was corpuscular). The crucial thing to note about this theory was its relationship to Newton’s alchemical investigations carried out in the 1670s, a practice that drew on the natural magic tradition in which a universal spirit or spiritus pervaded the cosmos, and which Newton thought might also act as a medium for occult (i.e. invisible) forces such as gravity and electricity. In fact, Newton dropped the aether hypothesis altogether in the 1680s while he was working on the Principia, instead favouring the idea of universal gravitational attraction, the powers of which could be mathematically quantified even while its cause remained unknown (Gouk 1999a: 251–257).
15The other relevant feature of the Principia to be noted is that it contains the first coherent mathematical explanation of the transmission of sound waves. Without delving into the mathematics and physics involved, it is sufficient to note that in order to treat sound propagation mathematically Newton had to imagine air as an elastic fluid through which forces, including sound waves, can be transmitted dynamically, spreading out spherically in all directions. Indeed, he had to go further by visualizing air as being made up of particles that oscillate backwards and forwards like tiny strings or pendulums, each one obeying the laws of simple harmonic motion. In effect, he translated Hooke’s qualitative model of a vibrating cosmos into one expressed in precise mathematical terms, a model which applied equally well both to light and to sound in air. Newton implicitly accepted that such musical models could provide a means of grasping fundamental truths about the universe, which itself was harmonic in nature (Gouk 1999a: 246–251).
16Having taken a back seat during Newton’s work on the Principia, the doctrine of a universal aether came to the fore again in the late 1680s and early 1690s when Newton began to develop his earlier optical investigations into something approaching publishable form, a project that was finally realized in the Opticks of 1704. Here Newton’s laws of light are presented as though they are derived from experiment alone, rather than inferred from any pre-existing magical theories such as the colour–harmony analogy. It is for this reason that his remarks about the relationship between music and colour are confined to the speculative section in Book III (Queries 12–14), where he discusses the analogies between colour and sound.
17Newton also referred to the “certain most subtle spirit” which “pervades and lies hid in all gross bodies” in the General Scholium that he added to the end of the second edition of the Principia (1713). The properties of this spirit are proposed to account for the entirety of chemistry, electricity and optics (Wallace 2003: 69). In addition, Newton further developed his speculations about the vibrating aether and its role in the transmission of light and gravity in the second English edition of the Opticks (1717), especially in Queries 17 to 31. It is in Query 22 that Newton first introduces his conjecture about the existence of a dense but subtle medium 700 times more elastic and 700 times rarer than air. In the following query he suggests that both vision and hearing are performed by the vibration of this aether, exciting the optic and auditory nerves – which he describes as “solid, pellucid and uniform” (i.e. not tubes as was generally thought) – connected to the place of sensation. However, it is in Query 24 that Newton elaborates his theory of a medium filling the entire solar system that may also serve to perform the actions of the rational will. This suggestion, i.e. that the spirit or spirits connecting the mind and body via the nervous system is the same spiritous substance that fills the heavens, has its roots in the Neoplatonic tradition, which as we have already seen exercized a significant influence on Newton’s thought. However, it is important to note that he was publicly dismissive of magic even though he plundered its resources for his own benefit. At the same time he was no mechanist, if by this we mean the exclusion of God as an explanatory principle of nature, but he nevertheless believed that the same laws operate throughout all parts of the universe.
18While the Principia is considered as Newton’s most lasting legacy to science, it is pertinent to note that his Opticks, including the speculative queries that were found in the back of the book, also had a significant impact on British natural philosophy (Gouk 2007). Indeed, we can see the influence of both these works in the prolific writings of the Scottish physician George Cheyne (c.1671–1743), who spent most of his medical career attending patients trying to recover from the excesses of a luxurious life (Guerrini 1989).
19An influential work of Cheyne’s that deliberately recalls Newton’s Principia is his best-selling Essay of Health and Long Life (1724), a work intended to help the reader keep well by means of the practical advice he offers. As in his later English Malady, Or a Treatise of Nervous Diseases of all Kinds in Three Parts (1733), Cheyne here notably ascribes most diseases to disorders of the nerves, rather than concentrating on the balance of humours as a pathway towards health. Thus instead of melancholy and the related afflictions of hysteria and hypochondria being caused by an excess of black bile or choler, Cheyne ascribes them to a poor state of the nerves and the animal spirits that flow through them. This shift away from the traditional humoral concept of health and disease towards the state of the nervous system as being responsible for a person’s sickness or wellbeing gradually became institutionalized in eighteenth-century medicine.
20The Essay of Health is also written in a style that deliberately recalls Newton’s Principia. Cheyne structured the Essay as a series of Propositions and Scholia about the nature of bodies and their motions. From a series of initial axioms readers are to understand that the soul may be understood as a “homunculus” in the brain, that man is a compound of soul and body, and that this compound is inscribed in the Laws of Nature, which can be known only through their effects, which is to say, experimentally. Here Cheyne draws a direct comparison between the “infinitely fine and elastick fluid or Spirit” that Newton speculated might cause gravity, and the intermediate, material substance that “may make the cement between the human Soul and Body, and may be the Instrument or Medium of all its Actions and Functions” (Cheyne 1724: 149). Just as there are principles of gravity or attraction inherent in bodies, so there may be an analogous principle of “Charity” in the animal spirits.
21Cheyne uses precisely the same analogy in the first section of The English Malady, which offers an introduction to the nature and causes of nervous diseases. Cheyne invites his readers to imagine that the human body is “a machine of an infinite number of and variety of different channels and pipes, filled with various and different liquors and fluids, perpetually running … and sending out little branches and outlets, to moisten, nourish, and repair the expences of living”. They also have to suppose that the intelligent principle, or soul, is situated somewhere in the brain, where the nerves, or “instruments of sensation” terminate. The soul is to be imagined as a musician, while the nerves are like keys of an organ that, on being touched, convey the sound and harmony to the musician, who is in a well-framed and well-tuned organ case (Cheyne 1733: 4).
22Perhaps assuming that this organ model is still too complex for most readers to comprehend, Cheyne goes on to offer a “more gross similitude” where the soul is now imagined as a bell in a steeple, one with an infinite number of clappers. Attached to these clappers are the nerves, ropes that are distributed to all extremities of the body. On being touched or pulled, each nerve conveys an impulse or stroke that immediately makes the bell sound. Both these instrumental models recall René Descartes’s description of the “animal machine” from his De homine figures, which was completed around 1633 and published in 1662 (see Kassler 1995: 43–48). At this point Cheyne finally admits that all these ways of thinking about how the mind and body influence each other are inadequate, and hopes that those acquainted with “the best philosophy” will go on to read what he has to say in the rest of this section, which also includes another discussion of the Newtonian aether, and its relevance to health.
23The aether is relevant to Cheyne’s theory of health chiefly because the nerves are to be thought of as “bundles of solid, springy, and elastic Threads or Filaments” that depend on the action of spirits (equivalent to the aether) for their responsiveness. In their optimum, well-tempered state, these threads are highly elastic or springy, toned, and responsive to the intentions of the mind, and as a result make good music. The healthy body, in short, is like a musical instrument that properly responds to the touch of the player:
Since the Mind resides, as has been said, in the common sensory, like a skilful Musician by a well-tuned Instrument; if the Organ be found, duly tempered and exactly adjusted […] the Musick will be distinct, agreeable and harmonious. But if the Organ be spoiled and broken […] it will not answer the Intention of the Musician, nor yield any distinctive Sound, or true Harmony. (Cheyne 1724: 158)
24Given the emphasis that Cheyne places on the body as a sympathetic and well-tuned instrument, it comes as something of a surprise to discover that music’s actual power over the mind and body finds no place in his reflections on health and nervous diseases. Also, Cheyne’s model of health is based on a concept of harmony, or balance, rather than on musical sound itself, this being understood as an external stimulus that has an immediate effect on the auditory nerves and animal spirits. In short (as in the case of Newton), there is nothing in Cheyne’s life or works to indicate that he was a music lover or that he was basing his theories on an understanding of its practice.
25The above is in quite sharp contrast to what we can infer about the author of Medicina Musica: Or a Mechanical Essay on the Effects of Singing, Musick, and Dancing, on Human Bodies. Revis’d and Corrected (Browne 1729). Richard Browne, who identified himself as an apothecary, was the first English author explicitly to discuss music’s therapeutic properties in the mechanical terms of the “new philosophy”. His central argument is that all three activities of singing, music and dancing can stimulate a plentiful secretion and flow of the animal spirits, which “consequently enable the Animal Machine to perform its various Functions to a greater degree of Perfection” (Browne 1729: 7). Singing, for example, exerts pressure on the lungs, causing stronger contractions of the heart, which increases the pulse and improves the circulation of the blood, which in turn leads to the secretion of spirits. However, in the context of treating nervous disorders, which at this time included the “hypochondriac, hysteric and melancholic affections”, Browne argues that curing is not only about the exercize of the voice, it is also about the act of listening to music, an activity which he appears to know something about:
by Singing we may possibly strike the Ear so pleasingly as to affect the Mind, and divert our anxious Thoughts, by the Succession of the brisk and lively Ideas of the Tune; we may certainly by this means chear and elevate the Soul, and by Sympathy invigorate the Motion of the Spirits. (Browne 1729: 28–9)
26Crucially, however, he draws a physical distinction between vulgar ears, which cannot convey to the mind an idea of harmony, and “musical ears”, which can. The latter’s enjoyment of every “tremulous oscillation” is due to the “exquisite configuration” of the auditory nerves that are located in the labyrinth and cochlea. The mind sympathetically responds to the vibrations of these nerves, an action that not only gives the soul pleasure, but also engenders pleasurable feelings in the body.
27Browne is similarly selective about the kind of music that he thinks of as beneficial. Specifically, he recommends listening to the sounds created by a “well-play’d Consort” of violins performing in the context of Italian opera, a form of music that at this time could be heard only by wealthy Londoners and which was also attracting controversy. Browne suggests that there are two types of music that can improve wellbeing, namely “the fine Adagio and Allegro parts in the Italian opera”. The “soft, languishing Trills, and melodious strains of an Adagio” played by a fiddle touch the nerves finely and produce a pleasing, ravishing sensation that causes the spirits to flow in gentle undulations. But the effect of a brisk and sprightly Allegro is to feel fresh life and vigour flow “from the persuasive Sound of such a sprightly harmonious Consort” (Browne 1729: 38–41.)
28Taking these effects to be self-evident for his readers, Browne goes on to consider how different sounds may prevent diseases, particularly those caused by the passions. For example, a soft adagio can soften the violent and irregular motions of the spirits that are felt in anger and rage, and it can also sooth a madman’s frenzy. However, if the same music is played to someone whose spirits are not disordered it may well enervate the body and lead to disease. The solution is to follow the sweetness of the adagio with a sprightly allegro, so that
by an agreeable Contrast of Musick we may not only contribute to the Preservation of our Healths, but at the same time indulge ourselves in the Enjoyment of one of the greatest Pleasures on Earth. (Browne 1729: 44)
29I propose to conclude this paper by showing the long-term influence of Newton’s speculations about the vibrative spirit immanent in all matter, particularly in the thinking of the philosopher and medical practitioner David Hartley (1705–1757). Hartley placed particular emphasis on the specifically musical nature of the spirit’s vibration and its function in the universe more generally, thereby offering a new interpretation of musica mundana for his time. Significantly, Hartley also identified musical vibrations as the means by which the brain operated in tandem with the nervous system, which marked another twist to the concept of musica humana. It turns out that Hartley’s theories of hearing and response to music (and speech) are embedded within a broader discussion of the nature of man, especially on the relationship between body and mind. His Observations on Man, His Frame, His Duty, and His Expectations, as he explains in its introduction, rests on two fundamental and related principles. The first of these, the doctrine of vibrations, is derived from “the hints concerning the performance of sensation and motion, which Sir Isaac Newton has given at the end of his Principia and in the questions annexed to his Optics”. The second principle, the doctrine of association, is taken from what “Mr Locke [had] delivered concerning the influence of association over our opinions and affections” (Hartley 1749: I, 5). Music “afford[s] ... various instances of the power of association”, and is thus both a model for the process and a means of furthering it. Taken together, Hartley argues, these principles of vibration and association can account for all actions of the body and mind, including the process whereby sensations come to generate simple and then more complex ideas in the mind, the mind being “that substance, agent, principle, etc. to which we refer the sensations, ideas, pleasures, pains and voluntary motions” (Hartley 1749: I, i).
30While Hartley sidesteps the question of the mind’s precise nature, he is in no doubt that the link between mind and body is effected by the white medullary substance of “the brain, spinal marrow and the nerves proceeding from them”, a substance which is not only the immediate instrument of sensation and motion, but also the immediate instrument by which ideas are presented to the mind (Hartley 1749: I, 7–8). In other words, sensibility – a term which was to have increasing importance later in the century – is conveyed by the nerves, while the sensitive soul or sensorium itself is located in the brain. In some respects Hartley’s identification of the medullary substance as the medium of sensation is quite traditional, in that it was generally believed that animal spirits flowing through the nerves served this function (Thomas Willis, for example, took this position in his Cerebri anatome of 1664). However, Hartley’s hypothesis was different in two important respects, both of which were due to his following suggestions originally made by Newton.
31The first of these differences is that Hartley reckons the nerves to be “solid capillaments” rather than the “small tubuli” favoured by theorists as notable as Boerhaave, Descartes and Galen. (Nevertheless, he rejects the idea that the nerves are like vibrating strings.) The second difference is that he thinks the medullary substance is comprised (at least in part) of infinitesimally small particles that are responsible for transmitting vibrations received by the exterior senses along the nerves to the brain. Furthermore, he thinks that these particles are similar, if not identical, to those making up the extremely fine material aether that Newton postulated might be distributed throughout the universe, a highly elastic medium responsible for transmitting light, gravity and electrical phenomena as well as human sensations, the particles of which vibrate like tiny pendulums or particles of sounding bodies communicating their motion according to the impacts they receive (Hartley 1749: I, 11). It is within this enlarged Newtonian context that Hartley’s discussion of all the outer senses, not just hearing, must be located.
32Although Hartley formally defers his discussion of the sense of hearing to a later part of the Observations, the subject in fact crops up much earlier, when he reflects on “how far the phenomena of musical and other inarticulate sounds are agreeable to the doctrine of vibrations” (Hartley 1749: I, 225). He thinks that both the intensity (“strength and feebleness”) and pitch (“gravity and acuteness”) of sounds are determined by variations in the pulses given off by sounding bodies, and suggests that grave tones are in general strong, and acute ones feeble. Indeed, he goes on to assert that musical (i.e. “uniform”) sounds, whether vocal or instrumental “are pleasant in proportion to their loudness, if not too excessive”. Exactly how this works is not entirely clear, however. The mind’s ability to distinguish variations in pitch may be due to the synchronous vibrations of the air and eardrum, giving rise to synchronous vibrations in the particles of the auditory nerves; alternatively it may be that each pulse of the air and oscillation of the eardrum excites innumerable infinitesimal vibrations in the auditory nerves, with the renewal of these at different intervals, according to the gravity or acuteness of the sound, giving rise to different sensations in the mind.
33Hartley accepts what is today known as the coincidence theory of consonance, remarking that two musical notes sounding together “afford a greater original pleasure than one, provided the ratios of their vibrations be sufficiently simple” (Hartley 1749: I, 226). Perhaps not surprisingly, Hartley’s list of concords reflects prevailing musical norms: they comprise the 8th, 5th, 4th, 3rd major or minor, and the 6th major or minor, the ratios being here respectively 1:2, 2:3, 3:4, 4:5, 5:6, 3:5 and 5:8. Examples of discords included here are the flat or sharp 2nd or 7th, or flat 5th, all of which are disagreeable. Interestingly, however, Hartley does not actually consider the boundary between concord and discord, between pleasure and pain, to be immutable but rather something acquired during the course of life. He suggests that to the ear of a child even the concords begin by being unpleasant but by dint of repetition they fall at last within the limits of pleasure. In the same way, discords eventually become pleasurable to the ears “of those that are much conversant of music”, to whom the “too frequent recurrency of concord cloys” (Hartley 1749: I, 227). Hartley thought that with its progression from the sensible to the spiritual, music could provide a means of effecting spiritual regeneration, its physical existence in vibrations and its receptivity to assimilation by association rendering it particularly suitable for this process.
34The cultivation of musical judgement fits into Hartley’s doctrine of association, which assumes that simple ideas are caused by external impressions made on the sensory organs, vibrations which are then transmitted via the medullary substance in the nerves to the brain (different regions of which are predisposed to particular types of vibration). A sufficient repetition of a sensation may leave a perceptible effect of a more permanent nature, that is an idea, which can recur in the mind at long distances of time after the impression was made. More complex ideas are raised by association, and it is also by association that we learn to exercize voluntary and semi-voluntary powers over our ideas, affections and bodily motions. Hartley claims that the spiritual state of self-annihilation might be brought about through the constant regulation of internal vibrations: “sensible pleasures and pains must be transferred by association more and more every day upon things that afford neither sensible pleasure nor sensible pain in themselves” (Hartley 1749: I, 82). The ultimate aim is to put ourselves, during our earthly lives, into a state approximating as nearly as possible to that of eternal blessedness.
*
35In this paper I have argued that although the terms musica humana and musica mundana dropped out of use during the seventeenth century, baroque and Enlightenment sciences effectively absorbed the Neoplatonic harmonia mundi tradition and the magical effects with which it was associated. However, there was a change in thinking over this time: what they kept of the tradition was the idea of a connection between the macrocosm and the microcosm (the same phenomena occur in the cosmos and in the body), but without necessarily formulating this link in terms of the solar system and the movement of the planets, i.e. the “harmony of the spheres”. What seems to have been more enduring thanks to Newton was the concept of a universal vibrating aether or aethers, which continued to inform British philosophical thinking well into the eighteenth century. This aether or spirit, the particles of which were imagined to vibrate like tiny musical strings or pendulums, was understood to constitute the medium between matter and non-matter, that is to say not just the connection between body and soul or mind but also the link between God and His Creation. By examining these cosmological, physiological and also theological theories, I have also shown that although the twin concepts of musica mundana and musica humana as such had no obvious currency in British Enlightenment thought, their underlying assumption that the heavens and human bodies are both constructed musically clearly endured.