Medieval science carried
on the views of the Hellenist civilization of Socrates, Plato, and Aristotle,
as shown by Alhazen's lost work A Book in which I have Summarized the Science
of Optics from the Two Books of Euclid and Ptolemy, to which I have added the Notions
of the First Discourse which is Missing from Ptolemy's Book from Ibn Abi
Usaibia's catalog, as cited in (Smith 2001).:91(vol.1),p.xv Alhazen conclusively disproved Ptolemy's theory of
vision.
Dürer's use of optics (1525)
But Alhacen retained Aristotle's
ontology; Roger Bacon, Witelo, and John Peckham each built-up a scholastic
ontology upon Alhazen's Book of Optics, a causal chain beginning with
sensation, perception, and finally apperception of the individual and universal
forms of Aristotle.[24] This model of vision became known
as Perspectivism, which was exploited and studied by the artists of the
Renaissance.
A. Mark Smith points out
the perspectivist theory of vision "is remarkably economical, reasonable,
and coherent", which pivots on three of Aristotle's four causes, formal,
material, and final.[25] Although Alhacen knew that a
scene imaged through an aperture is inverted, he argued that vision is about
perception. This was overturned by Kepler,[26]:p.102 who modelled the eye with a water-filled glass sphere, with
an aperture in front of it to model the entrance pupil. He found that all the
light from a single point of the scene was imaged at a single point at the back
of the glass sphere. The optical chain ends on the retina at the back of the
eye and the image is inverted.[nb 10]
Copernicus formulated a
heliocentric model of the solar system unlike the geocentric model of Ptolemy's
Almagest.
Galileo Galilei, father of
modern science.[27]
Galileo made innovative
use of experiment and mathematics. However his persecution began after Pope
Urban VIII blessed Galileo to write about the Copernican system. Galileo had
used arguments from the Pope and put them in the voice of the simpleton in the
work "Dialogue Concerning the Two Chief World Systems" which caused
great offense to him.[28]
In Northern Europe, the
new technology of the printing press was widely used to publish many arguments
including some that disagreed with church dogma. René Descartes and Francis
Bacon published philosophical arguments in favor of a new type of
non-Aristotelian science. Descartes argued that mathematics could be used in
order to study nature, as Galileo had done, and Bacon emphasized the importance
of experiment over contemplation. Bacon questioned the Aristotelian concepts of
formal cause and final cause, and promoted the idea that science should study
the laws of "simple" natures, such as heat, rather than assuming that
there is any specific nature, or "formal cause", of each complex type
of thing. This new modern science began to see itself as describing "laws
of nature". This updated approach to studies in nature was seen as
mechanistic. Bacon also argued that science should aim for the first time at
practical inventions for the improvement of all human life.
Age of Enlightenment
In the 17th
and 18th centuries, the project of modernity, as had been
promoted by Bacon and Descartes, led to rapid scientific advance and the
successful development of a new type of natural science, mathematical,
methodically experimental, and deliberately innovative. Newton and Leibniz
succeeded in developing a new physics, now referred to as Newtonian physics,
which could be confirmed by experiment and explained using mathematics. Leibniz
also incorporated terms from Aristotelian physics, but now being used in a new
non-teleological way, for example "energy" and "potential"
(modern versions of Aristotelian "energeia and potentia"). In the
style of Bacon, he assumed that different types of things all work according to
the same general laws of nature, with no special formal or final causes for
each type of thing. It is during this period that the word "science"
gradually became more commonly used to refer to a type of pursuit of a type of
knowledge, especially knowledge of nature — coming close in meaning to the old
term "natural philosophy".
