International Relations. A self-Study Guide to Theory

from religion.
In this long-term process, a more anthropocentric view incrementally re-
placed the theocentric world view of the Middle Ages. This process oc-
curred last but not least because of Martin Luther (Luther 1520: De liberate 
christiana/On the freedom of a Christian) and the Reformation, which called 
into question the “natural” authority of the Catholic church and strengthened 
the attempts to seek a truth free of tradition and dogma. As we will learn in 

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the next step, with the end of the Middle Ages, religion lost its prerogative 
for sole interpretation to modern science and technology. The transition 
from the geocentric world view to the heliocentric world view proved key to 
this process, since it was this change that gave birth to the scientific revolu-
tion. 
2.3. Scientific revolution and the rise of Cartesian-Newtonian 
science 
The “scientific revolution” was not a sudden event but rather a process that 
covered a long period of time; it lasted from the Early Modern Age at the end 
of the 15
th
century until the end of the 18
th
century. The scientific revolution 
is associated with the works of Nicolaus Copernicus (1473-1543), Johannes 
Kepler (1571-1630), Galileo (1564-1642), René Descartes (1596-1650), and 
Isaac Newton (1642-1727) – all of them astronomers, mathematicians, phi-
losophers, and physicists. The scientific revolution resulted in a development 
towards Cartesian-Newtonian science or a Cartesian-Newtonian world view. 
This process was crucial for the rise of the natural, empirical sciences and 
technology, and for their role and current status in the modern world.
Copernicus, Galileo, Kepler: the rise of experimental science 
The transition of the geocentric (Ptolemaic) world view to the heliocentric 
model as formulated by Copernicus (in 1543) and proved by Kepler’s laws 
and Galileo’s observations, is essential to the process of the scientific revolu-
tion because it gave birth to a new understanding of science. You can imag-
ine – and certainly know from history – that the Copernican world view was 
perceived as a threat to Christian cosmology, theology and Catholics morals. 
The trial against Galileo (1633) marked the height of the confrontation be-
tween religion and science but could not stop the spread of the heliocentric 
world view.
This transition from the geocentric to the heliocentric world view forms 
an important part of our discussion on the history of the idea of science be-
cause it brought about a new ideal of science, one based on new ontological, 
epistemological and methodological perspectives. Let me illustrate this in a 
few steps (drawing on Schupp 2003: 85-100; and Bedenig 2011: 75-82). 
First, it was through systematic observation with a telescope that Galileo dis-
covered the truth of Copernicus’s claims. This observation led Galileo to 
write his famous Dialogo sopra i due massimi sistemi (1632): a dialogue 
about the two main world systems, the Ptolemaic and the Copernican. Gali-

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leo’s work was guided by his belief in a law-like character of physical pro-
cesses. The search for these general laws has since been seen as the main 
goal of physics. Galileo claimed it was possible to obtain knowledge about 
these general laws through observation and measurement and the subsequent 
formulation of the laws in mathematical language. This continues to be the 
current objective of physics. For Galileo, there was a central position of the 
experiment as a scientific method: that a theory can be accepted only when 
experimentally “proved”. In fact, the natural sciences still apply Galileo’s ex-
perimental methodology today.
Out of fear of the church, Galileo’s work was first cautiously considered a 
“hypothetical model”. However, Kepler’s work subsequently demonstrated 
that the heliocentric model of Copernicus was not only a hypothetical model 
for the purpose of simplifying the calculations of planetary positions. Instead, 
Kepler “proved” the heliocentric model as a physical fact. Kepler’s work 
Epitome Astronomiae Copernicae was thus perhaps the first textbook on the 
heliocentric world view.
In short, starting with Galileo, experimental science now formed the core 
of inquiries about the world. Copernicus, Galileo, and Kepler all employed 
scientific methods. The methods of the natural sciences, based on empirical 
observation and its theoretical description and interpretation, had now taken 
their places at the heart of scientific inquiry. It is important to emphasize that 
this empirical orientation was a new focus in scientific thought. It was not 
based on Aristotelian and Platonic theoretical epistemology, but rather on ex-
perimental proof.
In sum, with the works of Galileo and Kepler, a process towards the rise 
of natural sciences as empirical science was put in motion in Europe, based 
on experience/experiment. This process also provided the foundation for new 
experiments because of new industrial tools. Thus, science and technology 
entered a new, mutually advantageous relationship at this time. 
Once experimental science emerged with Galileo, European philosophy 
also entered a new stage with the work of René Descartes. Descartes re-
established philosophy as a science, as part of physics and mathematics. 
From then on, the progress of European philosophical thought was closely 
linked to the progress of the empirical sciences, with physics and mathemat-
ics at the core (Lefèvre 2001: viii-x). This might sound strange at first, given 
that our traditional understanding of philosophy is not usually associated with 
these disciplines. Let us therefore take a closer look at the role mathematics 
and physics played for philosophy at this time. 

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Descartes and Newton 
René Descartes is well-known for his idea of the universe as a machine that 
operates according to strict mathematical laws (an excellent overview is pro-
vided by Schupp 2003: 110-133; see also Bedenig 2011: 83-86). His works 
can be seen as representative for the rise of the mechanical world view, which 
was developed further by Isaac Newton, the father of classical mechanics. 
Descartes formulated many of his major ideas in his Discours de la méthode 
pur bien conduire sa raison et chercher la vérité dans les science (1637), 
which discussed the “right method” of applying human reason to science. 
Descartes assumed the existence of rules responsible for the movements of 
things (with the world itself being of divine origin). Descartes’ aim was to 
come to know those rules; the question was, how? 
While trying to fulfill this aim, Descartes systematically transferred atom-
ism to the Copernican world view. He drew on the atomistic world view of 
Democritus and Epicurus, whose ideas had been revived in Renaissance. In 
an Epicurean-like way, Descartes assumed an atomistic world of matter and 
motion that operates under natural laws (see Harrison 2000: 2). Please re-
member that, in its ontological aspect, atomism refers to the view that the 
universe consists of tiny indivisible atoms, moving in infinite neutral empti-
ness, and the idea that all phenomena result from the collisions and the com-
binations of these atoms. Scholars such as Giordano Bruno already saw an 
analogy between the Greek idea of atomism and the Copernican system: at-
omism corresponds to the Copernican system in that the earth is not the cen-
ter of the universe but is itself a part (atom) of a neutral, infinite space with 
other celestial bodies (atoms). However, it was Descartes who finally ex-
pressed this idea in a systematic manner. The atoms/particles were referred to 
as “corpuscles” during Descartes’ time and it was by name of “corpuscle the-
ory” that Descartes spread the idea of atomism in his work. Corpuscle theory 
is similar to atomism in that all matter is seen as being composed of minute