The Utility of Natural Philosophy: Alchemy and Magic
From the thirteenth to the sixteenth century, Aristotelian natural philosophy dominated western attempts to make sense of the world of nature.1 This is not to say that western scholars were inattentive to the natural world in earlier centuries. The eighth-century theologian and historian Bede, based in the kingdom of Northumbria in north-eastern England, represents an important tradition of natural philosophy, though based on biblical exegesis than Aristotle.2 Yet Aristotle was seen to offer natural philosophy an informing intellectual framework, thus stimulating major translation projects throughout the twelfth and thirteenth centuries, in which Aristotle’s works and those of his commentators were translated from Greek and Arabic into Latin.3 While this tradition of commentary emerged in the ancient world,4 it was retrieved and expanded in the Middle Ages and Renaissance, allowing Aristotle’s intellectual vision to be continuously evaluated, corrected, and extended. Edward Grant’s assessment of medieval Aristotelian interpretation is helpful in understanding its appeal and persistence: ‘It was always a domain of both traditional and innovative concepts and interpretations and was, therefore, inevitably elastic and absorbent. Hence its most interesting feature was a capaciousness that knew few limits.’5
While some historians appear to consider that the appearance of this literature itself was the cause of the emergence of natural philosophy or even the natural sciences (though this latter term was not used frequently in the early Middle Ages),6 it seems clear that this interest in Aristotle and his interpreters was either the result of, or an essential accompaniment to, something more fundamental—a new interest in the philosophical and religious importance of the natural world.7 As a result of this enterprise, the concept of philosophia naturalis was widely discussed within the western church and the universities. While the Latin term natura could be used to translate Aristotle’s phusis, it came to have wider associations by the end of the twelfth century, when the concept of ‘nature’ had developed a range of meanings, including some close approximations to what modern readers understand by the term.8
For M. D. Chenu, the twelfth century witnessed a growing interest in the phenomenal world. Nature was now seen both as an object of study in itself, but also as a means of stimulating religious devotion through seeing nature as God’s creation.9 Chenu suggested that the twelfth century laid the foundations for this new interest in engaging the natural world, displacing a symbolic understanding of nature with a new concern to understand the structure, constitution, and underlying principles which seemed to underlie physical reality.10 Where traditional understandings of the natural world proceeded from a theological perspective, Chenu argued that such motivations were supplemented by a growing interest in acquiring an understanding of nature using methods that were not grounded upon or governed by theological principles.
Subsequent research has confirmed that a renewed interest in the study of nature emerged in the mid-twelfth century,11 and that scholars of this period drew on classical sources in developing a natural philosophy. This development is clearly related to the emergence of distinctively Christian, Islamic, and Jewish forms of natural philosophy during this period. Each found ways of drawing on the emerging tradition of natural philosophy, while accommodating this to the religious traditions that they represented. We shall return to this point later in this chapter (pp. 36–8). Yet it is important to appreciate that similar approaches emerged in Asia around this time, as forms of natural philosophy emerged in China, many of which placed an emphasis upon tian-ren-he-yi (the unity or harmony of heaven and humanity),12 thus giving rise to forms of thought that parallel comparable developments in western Europe during the Middle Ages and Renaissance. Although Chinese natural philosophers such as the twelfth-century writer Chu Tsi did not deal directly with some of the more abstract discussions that characterize modern science, there is a clear trajectory from his close attentiveness to nature to such an approach.13
This developing European interest in natural philosophy was well adapted to some significant trends within western religious and academic culture around this time, most notably the political separation of the ecclesiastical and secular realms resulting from the Investiture Controversy of the eleventh century, and the increasing structural separation—and hence intellectual isolation—of faculties of philosophy and theology in medieval universities.14 The growing interest in the concept of ‘natural law’ in the academic culture of the early medieval period also points to the interest in legal notions which were not grounded theologically.15 Although this concept was partly grounded in the notion of right reason, it also reflected a metaphysical belief in the ordering of the natural world, which was seen as lying beyond human intervention and manipulation.
For some of its interpreters, the task of natural law is to ‘interrelate systematically practical reason with a philosophy of nature’.16 A natural law theory therefore requires ‘a commitment to law as in some way “natural,” and nature as in some way normative’.17 For Aquinas, the concept of ‘natural law’ ultimately rests on a metaphysical realism of structured natural kinds and an epistemological realism by which this realist structure can be known by human observers of the natural world.18 This theme attracted much attention during the Renaissance, and was widely seen as a legitimate and generative topic of exploration.19
The foundation of universities in western Europe is widely seen as a turning point in intellectual history, marking the relocation of the pursuit of knowledge from the piety of the monastic schools of theology to a new academic space, theoretically independent of monarchical and ecclesiastical control.20 By far the most important such intellectual centre was the University of Paris. By the beginning of the thirteenth century, it is thought that there were around 4,000 students in residence at Paris, making up a tenth of the city’s population. The University of Paris was a complex corporate entity, a federation of three main collegiate bodies: nations, faculties, and colleges. Tensions arose over many issues within the Parisian Faculty of Arts, particularly in the first half of the thirteenth century, when religious orders—such as the Dominicans and Franciscans—became involved in university teaching, and were seen as a threat to the autonomy of Faculty members (such as secular priests) who were not linked with these orders.
Yet one of the most significant debates at Paris during the thirteenth century arose from a turf war between the disciplines of philosophy and theology and their associated Faculties, each of which considered itself to be intellectually distinct and autonomous.21 Aristotle’s natural philosophy came to demarcate a form of knowledge production that was potentially a threat to theology’s claim to intellectual supremacy, grounded in its privileged access to divine revelation.22 This tension was experienced within Islam in previous centuries, as growing interest in Aristotelian works led to strained relations with Islamic theology, especially on questions relating to creation and the eternity of the world.23 It was clear that Aristotle affirmed certain natural philosophical doctrines—such as the eternity of the universe—which contradicted, or at least were at least in tension with, certain traditional commitments of Jewish, Christian, and Islamic theology.24
While Thomas Aquinas rightly pointed out that Aristotle’s belief in the eternity of the world rested on questionable lines of reasoning, he nevertheless held that Aristotelian ideas were helpful in the articulation of Christian theology.25 However, Aquinas’s argument for the critical appropriation of Aristotle was met with a counter-demand for a general rejection of his ideas. In 1277, the bishop of Paris, Etienne Tempier, issued a series of condemnations of Aristotle’s ideas, in an ultimately unsuccessful attempt to curb their influence. Yet Tempier’s attempts to suppress natural philosophy failed to satisfy either theologians or philosophers at Paris. A better strategy was clearly required.
With the benefit of hindsight, the contribution of the Dominican Parisian theologian Albertus Magnus may be seen to have paved the way for a solution to this problem, which resulted in the rise of Aristotelian philosophy in the great universities of England, France, Germany, and Italy. An acknowledged expert on Aristotle, he drew a distinction between the realms of the natural and supernatural, arguing that philosophy offered an appropriate means of studying the former, and theology the latter. The breadth of his intellectual vision was such that he was able to hold together natural philosophy and theology, while delineating their respective realms of authority and inquiry.26 He was doubtless helped in this matter by Gregory IX’s bull Parens scientiarum (1231), which is widely credited with bringing about a decisive change in university culture, especially in encouraging the study of Aristotle’s Libri naturales.27
For Albertus, no special divine illumination is required in order to acquire a reliable knowledge of the natural world using intrinsic human powers of reasoning. The study of natural things (naturalia) can be conducted using a ‘natural light’; the study of revealed truth, however, requires divine grace and illumination. It is instructive to consider Albertus’s changing views on human nature, which show an increasing tendency to move away from a traditional Augustinian approach to human identity, and draw extensively on Aristotelian works (particularly his treatise On the Soul). Perhaps more importantly, he tends to weave citations from theological sources into wider conversations,28 rather than treating them as privileged.
In his assessment of the development of western philosophy, Gaukroger suggests that Albertus Magnus’s significance for the development of natural philosophy thus lay partly in a careful delineation of magisterial boundaries: ‘natural philosophy was concerned with natural truths, and theology with supernatural ones.’29 Natural philosophy was thus something that could be pursued independently of theology, in effect constituting a distinct scientia. This was not simply a matter of disciplinary specificity; it had implications for the location of this discipline within a university’s Faculty structures, and for the scholarly aptitudes and dispositions that accompanied such studies.30 To simplify what Albertus Magnus has to say on this matter, divine grace and illumination are not required for matters of philosophy, but are necessary for theology, which deals with the interpretation and apprehension of divine reality.31
A similar view was taken by Thomas Aquinas during his period at Paris. For Aquinas, who can be seen as the successor to Albertus Magnus, philosophy works in its own distinct manner; yet its conclusions may be seen as congruent with those of theology. This theme of convergence of outcomes, but not identity of methods and norms, is seen particularly in Aquinas’s Summa contra Gentiles, in which he deploys a natural philosophy, independent on Christian theology, in order to enable him to engage Muslims and pagans who would not accept the authority of the Christian Bible, or any arguments resting upon it.32 A natural philosophy thus offered what could be seen as a shared common natural language, enabling conversations across both disciplinary and religious divides.
The rise of the University as a discursive community, consisting of Faculties with different understandings of the nature of knowledge production, in effect created an environment in which natural philosophy and theology offered different means of making sense of the natural world and human nature, as well as engaging with questions relating to God. Thomas Aquinas illustrates this point well, in his discussion of the idea of ‘the empyrean heaven’. This, he argued ‘cannot be investigated by reason…but is held by authority’.33
‘Natural philosophy’ here is perhaps best understood as forms of reasoning which—following Albertus Magnus—rely on ‘natural’ capacities and resources, not requiring any special divine ‘illumination’. This development could thus be understood as a form of intellectual empowerment, shifting some important areas of discourse beyond the sole authority of the church or a Faculty of Theology. There are clear parallels with Anselm of Canterbury’s eleventh-century so-called ‘Ontological Argument’ for the existence of God (although as Anselm frames it, this is neither ‘ontological’ nor an ‘argument’), which offers a gateway to some modest theological reflections using the natural light of human reason, devoid of any specifically theological presuppositions.34 While some might see this as a threat to the authority of theology, most would see it as offering an expansion of intellectual possibilities, based on the traditional notion of ancillae theologiae—‘assistants to theology’, who are able to offer conceptual or methodological grist to theology’s mills, enabling refinement and development of its ideas.35 It could therefore be argued that a natural philosophy is a stimulus or gadfly to theology, perhaps encouraging a welcome interdisciplinarity.
One important intellectual and sociological factor stands out in this respect—the creation of a conceptual space for reflection on the grand questions of God, meaning, and nature which was not controlled or shaped by the church or any other religious body. We have already noted the importance of Christian writers such as Albertus Magnus and Thomas Aquinas in developing a viable relationship between Christian theology and natural philosophy (pp. 33–4). Yet such a critical religious appropriation of Aristotle was not a specifically Christian undertaking; similar projects were being developed by Jewish and Islamic writers in western Europe around this time. While medieval discussion of natural philosophy was often linked to the interpretation of Aristotelian texts, this was nuanced in different ways by Christian, Islamic, and Jewish writers.
Although many religious writers of this period expressed concerns about Aristotle’s views on the eternity of the world, they also appeared to have viewed his works as a religiously neutral resource capable of being quarried for the development of their own theological and philosophical agendas. This shared interest in Aristotle led to a philosophical ecumenism which was remarkable in the light of the political and religious tensions of this period. A good example of this related to the twelfth-century Andalusian Islamic philosopher Avicenna, a noted practitioner of falsafa, an Arabic philosophical tradition that considered itself as an ‘immediate heir and continuation of a Neoplatonized Aristotelianism’.36 Averroes’s commentaries were even translated into Hebrew so that Jewish interpreters of Aristotle might benefit from them.37
Judah ben Samuel Halevi, the leading Hebrew poet of his generation in medieval Spain, developed a natural philosophy which distinguished between the God who was disclosed through the natural order, and the God of Abraham, Isaac, and Jacob, who was disclosed through history.38 Halevi’s most significant work was originally written in Arabic, and later translated into Hebrew. In this work, Halevi contrasts the God of Aristotle, whom he designates as ‘Elohim’ and is known by reason and through the fixed order of nature, with the God of Abraham, known as ‘Adonai’, who is known through history, as interpreted through prophetic illumination. ‘One passionately yearns for Adonai with a passion that involves both “taste” and witness, while attachment to Elohim is by way of speculation.’39
Other topics that were debated within medieval Jewish natural philosophy included the question of whether there existed a plurality of universes, and how Aristotle was to be interpreted on this matter.40 Yet medieval Judaism was divided in its attitudes towards Aristotelianism. Jewish communities in the northern communities of Ashkenaz and Northern France were sceptical of its merits; those in the southern communities of Spain, Provence, and Italy were considerably more positive.41
Despite their theological differences, many Jewish, Muslim, and Christian natural philosophers of this era thus shared a belief in the importance of Aristotle as a foundational resource for a natural philosophy. Yet this shared respect for Aristotle was in decline by the end of the Middle Ages,42 with important consequences for the future directions of natural philosophy.
One important factor which contributed to the decline of Aristotle’s influence in the later Middle Ages was growing unease over the adequacy of his empirical observations—for example, the dogma of the ‘uninhabitability of the torrid zone’.43 Aristotle held that the habitable world was confined to the temperate zone between the Tropics and the northern frigid zone, which was clearly inconsistent with the growing body of knowledge arising from the ‘voyages of discovery’ of the late fifteenth and early sixteenth centuries, which made it clear that the ‘habitable’ world extended far south of the Equator.44 Cumulative observation by multiple contemporary observers increasingly came to be seen as providing a sufficient evidentiary foundation for overturning the once-authoritative judgments of Aristotle. This helps explain the growing importance of commentators on Aristotle in the Renaissance, who often nuanced or corrected his judgements on matters of importance for natural philosophy, including moving this tradition in a more empirical direction.45
Yet others were concerned that Aristotelian natural philosophy failed to articulate a moral vision, whether social or personal, enabling deeper questions of purpose and value in life to be addressed. The fourteenth-century Italian humanist Petrarch was particularly critical of the moral failures of the natural philosophers of his day, as well as their failure to engage deeper questions. ‘What use is it, I ask, to know the nature of beasts and birds and fish and snakes, and to ignore or neglect our human nature, the purpose of our birth, or whence we come whither we are bound?’46 Petrarch’s more fundamental concern was that philosophy fails to motivate us to act virtuously, which required inspiration rather than mere intellectual analysis.47 Petrarch here reflects the Renaissance immersion in classical antiquity, which led him to see philosophy as encouraging aspiration to moral excellence and the achievement of happiness.
The moral shortcomings of natural philosophy might, of course, be remedied by an appeal to natural law. As noted earlier (p. 32), a good case can be made for suggesting that natural philosophy lays the foundation for an understanding of lex naturalis—a concept of goodness or human obligation that is grounded in the deeper structures of reality, rather than being a human construct or invention.48 While this idea of a cosmic moral order with implications for human social ordering was of interest to university Faculties of Law, it was clearly also of public interest, and was often debated in Renaissance literature—for example, in Milton’s Paradise Lost, where the notion of natural law plays a ‘defiantly and definitely central’ role.49
Yet there are important questions about the wider cultural impact of natural philosophy at this time in western European history, especially in relation to the affective aspects of the natural world. Natural philosophy wrestled with questions of understanding nature, such as what first principles might be identified as lying behind natural structures and processes. Yet there is a substantial literature which points to both popular and academic interest in engaging matters such as the beauty and mystery of nature, the possibility that nature disclosed certain arcane ideas or mystical secrets, or that it might hold the key to personal transformation.50 Natural philosophy seemed to offer a somewhat dry and cerebral account of a natural world, whose beauty and complexity seemed to cry out for an engagement at the imaginative and emotional level. This approach to natural philosophy persisted into the early modern age. In his Ancilla philosophiae (1599), the Oxford Aristotelian philosopher John Case set out the object of natural philosophy in traditional Renaissance style as ‘the fullest knowledge of all things’. Not only does Case show no awareness of the importance of interpreting nature,51 he has little interest in engaging with the affective aspects of the natural world.
To appreciate the importance of this point, we may consider a quite different approach to the natural order developed in the twelfth century at the Parisian Abbey of St Victor. Hugh of St Victor developed a theology of the natural world which allowed its affective aspects to be appreciated, and incorporated into a Christian doctrine of creation. The study of nature as God’s creation led, not simply to a better understanding of the world, but to the enhancing of human wisdom.52 This has remained a classic theme of human engagement with nature: not simply understanding how nature works, but appreciating its deeper meaning and how this might make people wiser.53 Even in the early Middle Ages, we can see hints of a recognition of the incompleteness of purely rationalist assessments of the natural order, which seem to offer an inadequate account of the human experience of nature.
The limits of such rational accounts of the natural order is highlighted in Hildegard of Bingen’s remarkable Liber divinorum operum (‘The Book of Divine Works’), which explores an approach to natural philosophy that highlights the importance of affective and imaginative engagement with the world.54 Hildegard explores the affective links between God, human beings, and the cosmos through the notion of symphonia—an auditory image which highlights the harmony of the universe, and the pleasure that it gives to those who contemplate it.55 The contemplation of the natural order thus goes beyond intellectual reflection, in that it elicits pleasure, praise, and devotion, while giving the beholder a sense of place within the universe. The intensity of Hildegard’s engagement with nature, and the imagery she uses in expressing this, raise some important issues about the role of gender in engaging an allegedly ‘objective’ natural world, which have featured prominently in some recent feminist theological discussions.56
Hugh of St Victor also played an important role in developing the idea of nature and the Christian Bible as ‘God’s Two Books’, which could be read alongside each other in mutually illuminating ways.57 Although this was an interesting development in its own right, its importance for an understanding of natural philosophy relates to the question of the interpretation of nature—a matter that was rarely discussed in the Middle Ages, but which became important in the sixteenth century. It is now generally agreed that the imagery of ‘God’s Two Books’ led theologians to suggest that the well-established hermeneutical tools used to interpret the Bible could also be applied to the natural world,58 thus opening the way to the new interpretative empirical approaches to nature that emerged in the late sixteenth century. A set of familiar hermeneutical tools were available for the interpretation of the text of the book of nature, once the moment was right for their deployment. Yet although the conceptual foundations for such an interpretative approach to nature had been laid by 1200, their application dates from much later.
Aristotle’s view that theōria was of little practical value was not shared by all. While early medieval natural philosophy offered a restrictively rationalized account of the natural world, others turned to the disciplines of alchemy to expand the scope of a philosophy of nature. In 1994, Pamela Smith pointed out how Renaissance alchemy, and the hermetic philosophy that informed it, contributed significantly to the ‘habits of mind and practice that formed early modern philosophy’.59 The Renaissance interest in chrysopoeia (transmuting base metals into gold) that was evident in, for example, the alchemical Liber Lucis of John of Rupescissa,60 was not seen as something that was irrational or occult, but rather as a legitimate and entirely rational way of moving beyond an understanding of the natural world to controlling it, and repurposing natural processes to deliver desirable outcomes. Theōria offered an understanding of natural processes, which could lead to their redirection to enhance human well-being.
Many alchemical works of the early Middle Ages, such as Robert of Chester’s Liber de compositione alchemiae (1144), understood alchemy as an attempt to understand the fundamental constitution of the natural order, making it possible both to transform nature and heal humanity. While most now consider alchemy to be an arcane non-science with strongly mystical tendencies, its early medieval practitioners saw it as a form of natural philosophy, originating in Arabia.61 Alchemists and the practitioners of magic were sometimes described as ‘the perfect philosophers’, who had mastered the arts of natural philosophy, geometry, music, and astronomy necessary to a transformation of the natural world.62 The ‘philosopher’s stone’ was thus not seen simply as an agent of theoretical understanding, but of personal transformation—a point particularly evident in the English poet George Herbert’s poem ‘The Elixir’.63
Alchemy remained a significant element of western European engagement with nature until the end of the seventeenth century, when growing concern about the absence of reliable witnesses to supposed acts of ‘transmutation’ led to an erosion of their plausibility.64 Nevertheless, alchemical motifs can easily be discerned in early modern natural philosophy, such as that of Robert Boyle, which we shall consider presently. It was not until the development and general acceptance of Dalton’s ‘atomic hypothesis’ in the late eighteenth century that the notion of transmutation of metals was recognized as scientifically impossible.65
This leads us to consider the place of ‘magic’ in the Middle Ages. It is important to appreciate that writers of the Middle Ages did not make the easy distinction between ‘magic’ and ‘science’ that seems self-evidently true in the twenty-first century. William of Auvergne, who was Bishop of Paris from 1228 until his death in 1249, saw magic as part of the naturalis scientiae.66 Much magical literature of the Middle Ages was concerned with identifying the networks of natural forces in the universe and explaining how these can be manipulated to human advantage.67 These works included ‘lapidaries’ (studies of the magical powers attributed to different stones) and treatises on the medicinal uses of plants. For many in the Middle Ages and Renaissance, this offered an attractive alternative to the intellectual abstractions of Aristotelian natural philosophy. For reasons that are not completely understood, the domain of magic came to have increasingly feminine associations in the later Middle Ages, possibly reflecting its subversion of traditional gendered associations of intellectual authority.68
None of these considerations, of course, can really be considered to call into question the intellectual legitimacy of natural philosophy, as this emerged as a distinct way of reasoning and as a community of discourse in the early medieval period. It is simply to note some concerns which became increasingly obvious over the following centuries—namely, that this discipline was seen to offer an incomplete account of nature, thus raising the question of whether this deficiency could be remedied from within the discipline, either by expansion of its conceptual scope, or by creating alliances with other modes of human reflection which might alleviate these difficulties. While the process that Max Weber termed ‘Disenchantment’ is generally associated with the modern period, its roots can arguably be traced back much further.
This book is not a history of the concept of natural philosophy, but is rather an interpretative reflection on its past forms and present possibilities. While there is much more that needs to be said about the fortunes of natural philosophy in the Middle Ages, the specific purposes of this work are best served by moving directly to consider what might be considered to be the ‘Golden Age of Natural Philosophy’, beginning with the remarkable contribution of the late Renaissance philosopher Johannes Kepler. It was during this period that an interpretative empirical approach to natural philosophy, particularly in relation to the use of an experimental method, became firmly established—with significant results for how natural philosophy was understood and practised.