This document discusses the historical relationship between science, metaphysics, and theology, focusing on the concept of a "theology of nature". It describes how early modern scientists like Descartes and Maupertuis developed scientific theories and principles like the conservation of motion and least action based on theological and metaphysical foundations. Over time, the metaphysical and theological elements were removed, leaving just the scientific principles. The document then discusses later attempts in the 19th century to incorporate established scientific knowledge into theological and metaphysical frameworks, through things like the Gifford Lectures. Overall, it traces the complex interplay between science and theology over time.

1. Science, Metaphysics and
Theology of Nature

2. What is the Theology of Nature?
• Natural theology (lectures 6 & 7)
▫ A type of theology which does not depend on God’s revelation through scriptures,
miracles or prophecies (supernatural).
▫ Attempts to provides evidence of God’s existence drawn from reason and nature
• Theology of Nature I: Theology of nature  science (this lecture)
▫ Begins with a theological conception of nature based on divine attributes
▫ Proceeds from this metaphysical foundation to scientific inquiry
• Theology of Nature II: Science  theology of nature (this and next lecture)
▫ Incorporating the picture of nature as revealed by science into theology
▫ Tries to relate the findings of science to theology

3. Theology of Nature I
• Emphasis on Divine Reason and Intellect
• Look to divine attributes to uncover necessities in nature
• René Descartes
• Pierre Maupertuis
• The natural order follows from certain theological principles
• Human reason can uncover these

4. René Descartes (1596–1650)
“Gods’ perfection involves not only his being
immutable in himself, but also his operating in a
manner that is always consonant and
immutable… [Apart from the changes we know
directly from experience and revelation] we should
not suppose that any other changes occur in God’s
works, in case this suggests some inconstancy in
God. Thus God imparted various motions to the
parts of matter when he first created them, and he
now preserves this matter in the same way and it
follows that God likewise conserves the same
quantity of motion in matter.
Descartes, Principles of Philosophy, 1644.

5. Motion is Conserved

6. The Conservation of Motion
• “From God’s immutability we can know certain rules or laws
of nature… I showed what the laws of nature were, and
without basing my arguments on any principle other than the
infinite perfection of God.”
 Descartes, Principles of Philosophy (1644)
• “So in now maintaining the world by the same action and with
the same laws with which he created it he conserves motion;
not always contained in the same parts of matter, but
transferred from some parts to others depending on the ways
in which they come in contact.”
 Descartes, Principles of Philosophy (1644)

7. Pierre-Louis Moreau de Maupertuis
(1698–1759)
• Maupertuis sought laws of nature
“founded on the attributes of a Supreme
Intelligence”.
• God would ensure there was no waste in
the processes of the created world. God
would ‘economise’.
• Maupertuis supposed that there was some
quantity that would always be the
minimum needed to complete a process.
• He didn’t know what this quantity would
be but guided by this idea he went
looking.

8. Maupertuis’ Essay on Cosmology
“The Supreme Being is everywhere, but he is not equally visible everywhere
… Let us look for Him in the first laws he imposed on nature …We cannot
doubt that all things are regulated by a Supreme being, who, while he has
imprinted on matter, forces which show his power, has destined it to
execute effects which mark his wisdom … Let us calculate the motion of
bodies, but let us also consult the designs of Intelligence which makes them
move … I could have started with the law given by mathematicians and
confirmed by experience and looked there for marks of God’s wisdom and
power. But …. I thought it more certain and more useful to deduce these
laws from the attributes of an all-powerful and all-wise being. If those I
find in this way are the same as those observed in the universe, is that not
the strongest proof that that being exists and is the author of those laws?”
Pierre Louis Maupertuis, Essai de Cosmologie (1750)

9. Maupertuis’ Reasoning
• “Motion distributes itself such that the
quantity of action, once the change has taken
place, is the smallest possible… The laws of
movement and of rest deduced from this
principle being precisely the same as those
observed in nature, we can admire the
application of it to all phenomena. … [T]he
spectacle of the universe becomes so much
the grander, so much more beautiful, the
worthier of its Author, when one knows that a
small number of laws, most wisely
established, suffice for all movements.”
• Pierre Louis Maupertuis, Essai de Cosmologie (1750)

10. The Principle of Least Action
• Maupertuis initially used his principle
to explain the laws of reflection and
refraction of light.
• He was able to derive the laws of optics
(known from experience).
• The calculation of least action takes
into account the starting point (a) and
the end point (b).
• This became known as the Least
Action Principle.

11. • Leonard Euler develops a more general form of the Least Action Principle (LAP)
in the 1750s applicable to mechanics (some debate about whether Euler found
this principle first and whether Maupertuis plagiarised Leibniz).
• Both Maupertuis and Euler regarded this as providing rational support for belief
in God.
• The LAP later developed as part of Joseph-Louis Lagrange’s great mathematical
treatment of mechanical systems (Mechanique analytique, 1788), but without
the need for any theological assumptions.
• Later extended by William Hamilton (1805-65). Lagrangian and the
Hamiltonian approaches are mathematically complementary.
• The principle – more generally known as ‘extremum principles’ – describes the
way the physical universe operates and is used in classical dynamics, quantum
theory, and relativity
The History of the Principle

12. Other Examples
Theological considerations appear to have played a guiding role in the
experimental investigation of the inter-conversion and conservation of
forces in nature (electricity, magnetism, light, heat) in the 19th
Century.
• Hans Christian Ørsted (1777–1851)
The discovery of electromagnetism in 1820
• Ludvig Colding (1815–1888)
The “imperishability of forces” in the 1840s
• Michael Faraday (1791–1867)
The correlation of forces in the 1830s and 40s

13. Metaphysical Thinking in Science
• Metaphysical, religious, social and political ideas impulses may play,
and indeed have played, a crucial role in the birth and development
of scientific concepts and ideas.
▫ Malthusian economics  Darwin’s theory of evolution
▫ Race anthropology and war  Metchnikov’s theory of the
immune system
• It should not be surprising to find metaphysical and religious
impulses in the creative process of many great scientific thinkers of
the past (context of discovery)
• But during the course of the 19th century the grand metaphysical
systems disappeared from the public face of scientific knowledge

14. The Disappearance of Influences
• Physicists generally no longer regard extremum principles as having
any metaphysical or theological implications (two exceptions – Max
Plank and David Bohm).
• Conservations laws in physics no longer invoke theological or
metaphysical principles.
“Whatever cultural influences went into the discovery of Maxwell’s
equations and other laws of nature have been refined away, like slag
from ore. Maxwell’s equations are now understood in the same way
by everyone with a valid comprehension of electricity and magnetism”
Steven Weinberg, Facing Up (2001)
• What should we conclude from all of this – both historically and
philosophically?

15. Metaphysics and Science
The bridge (science) and the scaffolding (metaphysics)

16. Science Purged of Metaphysics
• One the edifice of science is erected,
one may discard the metaphysical
scaffolding
• Cartesian metaphysics was stripped
away from the law of conservation
• The least action principle ceased to
retain the status of a metaphysical
postulate
• The edifice of science can stand as the
finished product, like the arch after the
keystone has been inserted.

17. The Historical Formation of
Modern Scientific Disciplines
In the course of the long 19th century … the scientific enterprise underwent
enormous and unprecedented intellectual and social changes.
Developments in the sciences during this period arguably equaled or
exceeded those in natural philosophy during the Scientific Revolution of the
sixteenth and seventeenth centuries, and in virtually every respect, be it
intellectual range, theory formation, empirical results, or instrumentation.
Moreover the sciences underwent unprecedented institutional growth and
had a large role in reshaping society – just as society helped reshape them
… [I]t was in the nineteenth century that modern disciplines of chemistry,
physics, mathematics, biology, and the earth sciences, as well as the social
sciences, assumed their more or less contemporary form and reshaped the
institutional landscape of science.
David Cahan, From Natural Philosophy to the Sciences (2003)

18. Science, Philosophy
and Religion in the 19th Century
The reform of the university in the 19th C led
to a deepening institutional division
between philosophy and science
• Institutional separation
• Disciplinary and pedagogical
specialization
• New forms of patronage
A fundamentally different relationship
between the sciences and religion
crystallized during the course of the 19th C

19. The Secularization of Science
• The term ‘scientist’ first coined by William Whewell in 1833.
• During the 19th century the term ‘science’ came increasingly to refer to
disciplines (chemistry, physics, biology, geology) for studying the natural
world as a secular object
• Natural philosophy and natural history had retained close ties to natural
theology up until the 18th century
• By the middle of the 19th century, the sciences became more closely
connected to the material, commercial and political interests of the state
and industry.
• New forms of patronage meant that science increasingly became tied to the
exploitation of natural resources and for material and social improvement

20. The Intellectual Separation of Science and
Metaphysics
• Immanuel Kant (1724–1804)
▫ Critical Philosophy (1781–1790)
▫ Distinguished between the realm of the knowable (empirical knowledge) and the
unknowable (thing-in-itself)
• Auguste Comte (1798–1857)
▫ Positivism (1830–1850)
▫ The law of historical stages: theological  metaphysical  positive/scientific
• Thomas Huxley (1825–1895)
▫ Agnosticism (1869–1890)
▫ Huxley drew a sharp line between empirical knowledge and metaphysics (‘unknowable’)

21. • Theology of nature, as I have defined it so far, served as a source of
inspiration for the scientific work of figures like Descartes,
Maupertuis and Faraday
• But what about going the opposite way?
• Can the direction of argument from philosophy and theology to
science (or physics) be reversed?
• Do variational principles in physics still presuppose a metaphysics?
(See Stephen’s Lecture 23)
• But by the late 19th century, by the time science had established its
autonomy, we do begin to see the reverse trend as a historical
phenomenon.
From Science to Metaphysics?

22. Theology of Nature II
• Here we find the attempt to develop a theology
of nature by drawing on established scientific
knowledge or theories (e.g. Cosmology,
Darwinian evolution)
• This was not a return earlier forms of natural
theology, such as the argument from design (or
‘God of the Gaps’).
• Rather it constitutes the attempt to develop a
theistic metaphysics, based on the findings of
modern science.

23. Science and Theology of Nature
The Gifford Lectures
• Established in 1887 to “promote and diffuse the study of natural theology”
• Presented by eminent scientists, theologians and philosophers
• University of St Andrews, University of Glasgow, University of Aberdeen and
University of Edinburgh.
Popular Science?
• Arthur Eddington, The Nature of the Physical World (1929)
• Hermann Weyl, The Open World (1932)
• Theodore Dobzhansky, Nothing in Biology Makes Sense Except in the Light of
Evolution (1973)

24. Hermann Weyl (1885–1955)
Modern science, insofar as I am familiar with it
through my own scientific work, mathematics
and physics, makes the world appear more and
more an open one, as a world not closed but
pointing beyond itself. Or as Franz Werfeld
expresses it in pregnant wording of one of his
poems
“Diese Welt ist nicht die Welt allein”
[This world is not the only world]
A mathematician steps before you, speaks about
metaphysics and does not hesitate to use the
name of God. That is an unusual practice
nowadays.
Herman Weyl, The Open World (1932)

25. Towards a Theology of Nature?
Instead of a natural theology, I advocate a
theology of nature, which is based primarily
on religious experience and the life of the
religious community but which includes
some reformulation of traditional doctrines
in the light of science. Theological doctrines
start as human interpretations of individual
and communal experience and are therefore
subject to revision. Our understanding of
God’s relation to nature always reflects our
view of nature [and therefore should
incorporate our best science].
Ian Barbour, Religion and Science, 1997

26. Modern Theologies of Nature?