The Book of Healing (Arabic: کتاب الشفاء, romanized: Kitāb al-Shifāʾ; Latin: Sufficientia; also known as The Cure or Assepha) is a scientific and philosophical encyclopedia written by Abu Ali ibn Sīna (also known as Avicenna) from medieval Persia, near Bukhara in Maverounnahr.
The book is divided into four parts: logic, natural sciences, mathematics (a quadrivium of arithmetic, geometry, astronomy), and metaphysics.
[6] Ibn Sina made the following observation on the theories held at the time on fossils and the petrifaction of plants and animals: "If what is said concerning the petrifaction of animals and plants is true, the cause of this (phenomenon) is a powerful mineralizing and petrifying virtue which arises in certain stony spots, or emanates suddenly from the earth during earthquake and subsidences, and petrifies whatever comes into contact with it.
He states that anger heralds the transition of melancholia to mania, and explains that humidity inside the head can contribute to mood disorders.
Avicenna sent a message to the patient, asking him to be happy as the butcher was coming to slaughter him, and the sick man rejoiced.
The patient was then offered food which he ate eagerly, and gradually "gained strength, got rid of his delusion, and was completely cured.
[10] After the Latin translations of the 12th century, his writings on logic were also an important influence on Western medieval writers such as Albertus Magnus.
Following al-Farabi's lead, Avicenna initiated a full-fledged inquiry into the question of being, in which he distinguished between essence (mahiat) and existence (wujud).
[14] Avicenna's proof for the existence of God was the first ontological argument, which he proposes in the "Metaphysics" section of The Book of Healing.
"[17] In the "Al-Burhan" ('On Demonstration') section of the book, Avicenna discusses the philosophy of science and describes an early scientific method of inquiry.
Avicenna explains the issue of a proper methodology for scientific inquiry and the question of "How does one acquire the first principles of a science?"
He asks how a scientist would arrive at "the initial axioms or hypotheses of a deductive science without inferring them from some more basic premises?"
Avicenna criticizes Aristotelian induction, arguing that "it does not lead to the absolute, universal, and certain premises that it purports to provide."