Editing Albert Brudzewski (section)

== Views and contributions ==
[[File:Wojciech Brudzewski monument 01.jpg|thumb|Statute of Albert Brudzewski in [[Brudzew, Turek County]]{{Efn|name=Brudzew}}]]

=== On Averroes ===
Brudzewski was seen as influential and persuasive astronomer, a fictionalist, and an opponent of Middle Ages [[Al-Andalus|Andalusian]] scholar [[Averroes]] (Ibn Rushd''')'''. Averroes disagreed with the majority of the astronomer [[Ptolemy]]'s work. He believed that Ptolemy's devices and principles disobeyed the fundamental principles and basic consequences of [[Aristotelian physics]]. Averroes worked to replace the Ptolemaic astronomical system with a novel system that was similar to a system created by [[Eudoxus of Cnidus|Eudoxus]]. Albert Brudzewski disagreed and criticized Averroes immediately. The major dispute was the figuring out the number of celestial orbs or spheres that lay in the heavens. Averroes refused to believe that there was a ninth sphere in the heavens. He believed that the creation of all celestial beings had to arise from the stars, but the ninth sphere did not possess any stars, so this could not be true. Albert Brudzewski argued with this and said that the heavens possessed more than ten spheres. He believed that the Sun itself had three spheres and the planets had their own as well.<ref name=":0" />

To make sense and clarify to his followers, Brudzewski said that the terms 'orb' or 'sphere' had three meanings of interpretation. The first meaning could be the whole entire heavens was designated into a single object which was the orb or sphere. This object was not separate from the whole heavens yet it could exist by itself. The second meaning he paralleled it to the sphere or orb from Peurbach's ''Theoricae novae planetarum'' although it was unconventional, it still existed in the heavens. The third meaning or clarification of orb was an orb that was aligned with the Earth. The third meaning was actually a collection of orbs that was crucial to the motion of a planet.<ref name=":0" />

Brudzewski further disputes Averroes by depending on the assumptions of Aristotle. He said that Aristotle demonstrated and verified five claims about the heavens that could disprove Averroes. The first claim was that the heavens was a simple being. The second claim was that because the heavens was a simple being, the motion of the being also had to be simple and uncomplicated. There could only be one motion and it had to follow the laws of nature. The third claim was that any motion that did not follow the laws of nature had to have an addition motion that did follow the laws of nature. The fourth claim was that a single sphere or orb could not be moved by several motions because it was a simple body. The fifth claim was that any superior or greater orb could have an impact on lesser orbs and spheres but the lesser orbs and spheres could not have any leverage on the superior's ones.<ref name=":0" />

To finally disprove Averroes, Brudzewski mentions the three recognizable motions of the sphere of fixed stars. The first motion was that the sphere possessed a daily rotation that occurred from the East to the West. The second motion was movement of the sphere in the opposition direction from West to East. The third motion was a cyclical motion that Brudzewski named [[trepidation]]. Brudzewski gave these three motions to the last three spheres respectively. With the assumptions of Aristotle as well as the motions of the sphere of the fixed stars, Brudzewski is able to prove that Averroes is wrong about the number of celestial spheres in the heavens.<ref name=":0" />

=== On the heavens and planetary motion ===
Albert Brudzewski was known as a fictionalist. He did not think that the motions of the heavens were understood by any human.<ref>{{cite book |last=Copernicus |first=Nicolaus |url=https://books.google.com/books?id=LH4tWpJzzCcC&q=Albert+Brudzewski&pg=PA3 |title=On the Revolutions of Heavenly Spheres |date=2010-08-27 |publisher=Prometheus Books |isbn=978-1-61592-082-2 |language=en}}</ref> [[Richard of Wallingford]], an astronomer in the 1300s, had an opposing view for the spheres of the planets. He claimed that no mortal knows whether eccentrics truly exist in the spheres of the planets, but spirits could give humans revelations about the true planetary motion of the heavens through mathematicians.<ref name=":0">{{cite journal |last=Barker |first=Peter |date=May 2013 |title=Albert of Brudzewo's Little Commentary on George Peurbach's 'Theoricae Novae Planetarum' |url=http://dx.doi.org/10.1177/002182861304400201 |journal=Journal for the History of Astronomy |volume=44 |issue=2 |pages=125–148 |doi=10.1177/002182861304400201 |bibcode=2013JHA....44..125B |s2cid=118730125 |issn=0021-8286}}</ref> This claim limits the astronomical knowledge of mortals and suggests that spirits do not have the same limitations. Brudzewski acknowledges the existence of these viewpoints but criticized their validity. To astronomers, spirits had an accurate knowledge of the number of celestial orbs. Although, he did not want to discredit the ability of mortals to make claims based on astronomical observations.Brudzewski made the claim for the fundamental principle of astrology that the heavens exert causal influences on the Earth.<ref name=":0" />

The paths of planets were thought to be moved by orbs instead of circles. This was a claim by Brudzeski about causal relationships between the planets and their motion. With this view, he disagreed with Averroes about the number of orbs, the concept of [[Deferent and epicycle|epicycles and eccentric circles]], and on theoretical orbs. Brudzewski was seen as a source for some of Copernicus's work on orbs, specifically with the [[Tusi couple]].<ref name=":0" />

=== Tusi couple ===
The Tusi couple was known as an epicycle arrangement that creates straight line motion of the planets, created by Copernicus.<ref>{{cite journal |last=Watson |first=A |date=1919 |title=Copernicus |journal=Journal of the Royal Astronomical Society of Canada |volume=13 |pages=264–282}}</ref> Some think that Brudzewski is the source for Copernicus's model of the Tusi couple. Albert does account for the moon and its double epicycles where he mentions a spot on the moon.<ref name=":0" /> The spot on the Moon is the problem of explaining the appearance of the face of the Moon when always viewing the Earth. These views were not aligned with the Tusi couple. Although, it is speculated that Copernicus could have encountered such a model, where the primary epicycle carries the center of a second epicycle. This is not the Tusi couple, but it could be slightly changed to match its model. The spot on the moon that is always viewed from the Earth would not appear if there was no epicyclical motion of the moon. The motion of the moon was termed as prosneusis motion which was part of the lunar theory. This motion means motion of inclination and turning, which corresponds to the single epicycle in Ptolemy's theory of the moon, and the two epicycles in Brudzewski's model.<ref name=":0" />

Brudzewski was aware of the possibility of linear motions from circular motions based on his model of Mercury's motion. This could be an alternative way that Copernicus generated his idea of linear motion for the Tusi couple. Although it seems that Copernicus used Albert's ideas, he highly relied on Islamic sources for the Tusi couple. Copernicus's parameters for the moon are exactly the same as those of [[Ibn al-Shatir]]. It is unclear where Copernicus truly got his ideas.<ref name=":0" />

=== On philosophy ===
Brudzewski was [[Nominalism|nominalist]], but defended [[humanism]].<ref name=":7" /> Along with Cracow Academy, Brudzewski sided with the advocates of [[philosophical realism]] in the defense of [[scholasticism]].<ref name=":7" />