Ibn Sīnā wrote at least one treatise on alchemy, but several others have been falsely attributed to him. His Logic, Metaphysics, Physics, and De Caelo, are treatises giving a synoptic view of Aristotelian doctrine, though Metaphysics demonstrates a significant departure from the brand of Neoplatonism known as Aristotelianism in Ibn Sīnā's world; Arabic philosophers[who?][year needed] have hinted at the idea that Ibn Sīnā was attempting to "re-Aristotelianise" Muslim philosophy in its entirety, unlike his predecessors, who accepted the conflation of Platonic, Aristotelian, Neo- and Middle-Platonic works transmitted into the Muslim world.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What doctrine is some of Avicenna's works based around?
Ah, so.. Aristotelian doctrine

Earthworms are Oligochaetes that support terrestrial food chains both as prey and in some regions are important in aeration and enriching of soil. The burrowing of marine polychaetes, which may constitute up to a third of all species in near-shore environments, encourages the development of ecosystems by enabling water and oxygen to penetrate the sea floor. In addition to improving soil fertility, annelids serve humans as food and as bait. Scientists observe annelids to monitor the quality of marine and fresh water. Although blood-letting is no longer in favor with doctors, some leech species are regarded as endangered species because they have been over-harvested for this purpose in the last few centuries. Ragworms' jaws are now being studied by engineers as they offer an exceptional combination of lightness and strength.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Why are no leeches endangered?
Ah, so.. unanswerable

Combined with this influx of classical ideas was the invention of printing which facilitated dissemination of the printed word and democratized learning. These two things would later lead to the Protestant Reformation. Toward the end of the period, an era of discovery began (Age of Discovery). The rise of the Ottoman Empire, culminating in the Fall of Constantinople in 1453, eroded the last remnants of the Byzantine Empire and cut off trading possibilities with the east. Europeans were forced to seek new trading routes, leading to the expedition of Columbus to the Americas in 1492, and Vasco da Gama’s circumnavigation of India and Africa in 1498. Their discoveries strengthened the economy and power of European nations.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In what year did Constantinople fall?
Ah, so..
1453