[10] Avempace enjoyed music and wine with the governor and also composed panegyrics and muwashshahat to publicly praise Ibn Tifilwit, who rewarded him by nominating him as his vizier.
In the beginning of his career, he wrote the manuscript Risālah fī l-alḥān (Tract on melodies) and incorporated his commentary on al-Fārābī’s treatise based on music.
According to biographer al-Maqqarī, Avempace's passion for music was due to poetry and had “the virtue of dispelling the sadness and pain of the hearts [sic].” He included his scientific knowledge and wit in many poems.
Writings by Ahmad al-Maqqari gives us insight into the hostility and disagreements between Avempace and the father of a famous physician respected by Ibn Tashfin, Abd al-Malik.
His famous works included Tadbīr al-mutawaḥḥid (Management of the Solitary), the Kitāb al-nafs (Book on the Soul), and the Risāla fī l-Ghāya al-insāniyya (Treatise on the Objective of Human Beings).
"However, the most important idea from Avempace's system was not mentioned in the treatise, "how the union of the active intellect with man occurs, which is the ultimate goal being pursued by the solitary.
Ibn Bajjah, in particular, takes from Plato's idea of the necessary connection between man and city with a bit of a twist.
Avempace imagines the perfect city as a place that is free of any beliefs or opinions that are in opposition of the truth and where true science reigns supreme.
If it is said in general, it points out that perception intents knowing particular [aspects] of a matter, from which a universal proposition results.
[19] These ideas are consistent with Aristotle's descriptions of the soul and its properties in his treatise De Anima, though there is speculation that there were no Arabic transcriptions available to Avempace.
In Chapter 1 of his greatest philosophical work, The Kuzari, Halevi summarizes three ideas directly influenced by works of Ibn Bajja: one's unification with the Active Intellect is attainable during their lifetime, this unification implies cognitive identity with others who are aware of the truth, and a philosopher's life is a solitary regimen.
[24] The renowned polymath and Jewish philosopher, Maimonides, was possibly born in the same year of Avempace's death, yet he preserved and studied the works of the deceased Andalusian.
Maimonides admired Avempace for his achievements, stating that "[Ibn Bajja] was a great and wise philosopher, and all of his works are right and correct".
[25] In one of his three major works, The Guide for the Perplexed, Maimonides assesses Hebrew Bible theology with Aristotelian philosophy, directly drawing influence from Ibn Bajja philosophical and scientific ideas.
As a result, in order to be spiritually healthy and, therefore, happy, we must obtain knowledge and search for the truth.
I have not heard it from his pupils; and even if it be correct that he discovered such a system, he has not gained much by it, for eccentricity is likewise contrary to the principles laid down by Aristotle....
On the other hand, Aristotle's Arabic commentator Ibn al-Bitriq considered "the Milky Way to be a phenomenon exclusively of the heavenly spheres, not of the upper part of the atmosphere" and that the "light of those stars makes a visible patch because they are so close."
Avempace's view differed from both, as he considered "the Milky Way to be a phenomenon both of the spheres above the moon and of the sublunar region."
Their light forms a “continuous image” (khayâl muttasil) on the surface of the body which is like a “tent” (takhawwum) under the fierily element and over the air which it covers.
Avempace defines the continuous image as the result of refraction (in‛ikâs) and supports its explanation with an observation of a conjunction of two planets, Jupiter and Mars which took place in 500/1106-7.
In the 13th century, the Maragha astronomer Qotb al-Din Shirazi identified this observation as the transit of Venus and Mercury.
[18] Text 71 of Averroes' commentary on Aristotle's Physics contains a discussion on Avempace's theory of motion, as well as the following quotation from the seventh book of Avempace's lost work on physics: "And this resistance which is between the plenum and the body which is moved in it, is that between which, and the potency of the void, Aristotle made the proportion in his fourth book; and what is believed to be his opinion, is not so.
And if this assumption were true, it would then be the case that no motion would require time except because of something resisting it for the medium seems to impede the thing moved.
If what Aristotle said was true, natural motion in a supposed void would not meet any resistance and it would not take time but be instantaneous.
[14] From Text 71; Ernest A. Moody, who is a notable philosopher, medievalist, and logician, offered four main reasons in favor of the view that Avempace was at least a major thinker within the paradigm of the "Theory of an 'impressed force.
"Internal coherence with this "law of motion" requires, Moody believes, also a defense of the theory of an impressed force - as we find for exampled in Philopponus himself."[7]3.
"Avempace's appeal to an 'impressed force' was also reflected in the fact that 'if we use modern terms, it might be said that the force of gravity, for Avempace, is not determined essentially as a relation between the masses of different bodies, but is conceived as an absolute indwelling power of self-motion animating the body like a soul."[7]4.
"The theory of an 'impressed force' appears to have been upheld by Al-Bitrogi, who was influenced ins ideas by Avempace's disciple Ibn-Tofail.
An interesting piece by Avempace on the theory of projectile motion comes from his example involving a magnet and iron filaments.
He also writes about the reproductive nature of plants and their supposed genders based on his observations of palm and fig trees.