Hibat Allah Abu'l-Barakat al-Baghdaadi

Hibat Allah Abu'l-Barakat al-Baghdaadi (c. 1080-1165) was a Muslim physicist, philosopher, psychologist and scientist of Jewish-Arab descent from Baghdad, Iraq. His Hebrew birth name was Nathanel. It is known that Abu-l-Barakat had converted to Islam from Judaism at some point in his life. [Routledge History of Philosophy By Stuart Shanker, John Marenbon, George Henry Radcliffe Parkinson, pg. 76] His thought influenced the Illuminationist school of classical Islamic philosophy, the medieval Jewish philosopher 'Izz ad-Dawla Ibn Kammuna,citation|first=Y. Tzvi|last=Langermann|date=1998|contribution=al-Baghdadi, Abu 'l-Barakat (fl. c.1200-50)|title=Islamic Philosophy|publisher=Routledge Encyclopedia of Philosophy|url=http://www.muslimphilosophy.com/ip/rep/J008.htm|accessdate=2008-02-03] and the Christian philosophers Jean Buridan and Albert of Saxony.

"Kitab al-Mu'tabar"

He wrote a critique of Aristotelian philosophy and Aristotelian physics entitled "Kitab al-Mu'tabar", in which he developed concepts which resemble several modern theories in physics.

Motion

According to A.C. Crombie, al-Baghdaadi was a follower of Avicennism, who

proposed an explanation of the acceleration of falling bodies by the accumulation of successive increments of power with successive increments of velocity. [A. C. Crombie, "Augustine to Galileo 2", p. 67.]

According to Shlomo Pines, al-Baghdaadi's theory of motion was thus

the oldest negation of Aristotle's fundamental dynamic law [namely, that a constant force produces a uniform motion] , [and is thus an] anticipation in a vague fashion of the fundamental law of classical mechanics [namely, that a force applied continuously produces acceleration] . [cite encyclopedia
last = Pines
first = Shlomo
title = Abu'l-Barakāt al-Baghdādī , Hibat Allah
encyclopedia = Dictionary of Scientific Biography
volume = 1
pages = 26-28
publisher = Charles Scribner's Sons
location = New York
date = 1970
isbn = 0684101149
(cf. Abel B. Franco (October 2003). "Avempace, Projectile Motion, and Impetus Theory", "Journal of the History of Ideas" 64 (4), p. 521-546 [528] .)]

Al-Baghdaadi's theory of motion was vaguely foreshadowing Newton's second law of motion, by distinguishing between velocity and acceleration and for showing that force is proportional to acceleration rather than velocity. The 14th-century philosophers Jean Buridan and Albert of Saxony later refer to Abu'l-Barakat in explaining that the acceleration of a falling body is a result of its increasing impetus. Abu'l-Barakat also modified Avicenna's theory of projectile motion, and stated that the mover imparts a violent inclination ("mayl qasri") on the moved and that this diminishes as the moving object distances itself from the mover.citation|title=Pseudo-Avicenna, Liber Celi Et Mundi: A Critical Edition|first=Oliver|last=Gutman|publisher=Brill Publishers|year=2003|isbn=9004132287|page=193]

Al-Baghdaadi also suggested that motion is relative, writing that "there is motion only if the relative positions of the bodies in question change." This vaguely foreshadows the concept of relativity, in recognizing the idea of there being different frames of references. Another theory he developed which has no modern counterpart is his theory that "each type of body has a characteristic velocity that reaches its maximum when its motion encounters no resistance."

pace and Time

Al-Baghdaadi criticized Aristotle's concept of time as "the measure of motion" and instead redefines the concept with his own definition of time as "the measure of being", thus distinguishing between space and time, and reclassifying time as a metaphysical concept rather than a physical one. The scholar Y. Tzvi Langermann writes:

Psychology

On his contributions to Islamic psychology, Langermann writes:

References