Avicenna continues to write compendious works, producing a notable philosophical encyclopedia and numerous works on medicine.

The Book of Healing (Arabic: Kitab Al-Shifaʾ, Latin: Sufficientia) is a scientific and philosophical encyclopedia.

Despite its English title, it is not concerned with medicine.

Also called The Cure, it is intended to "cure" or "heal" ignorance of the soul.

He probably began to compose the al-Shifa in 1014, completed it around 1020, and published it in 1027.

The book is divided into four parts: logic, natural sciences, mathematics (a quadrivium of arithmetic, geometry, astronomy, and music), and metaphysics.

It is influenced by ancient Greek philosophers, such as Aristotle, Hellenistic thinkers such as Ptolemy, earlier Persian and Muslim scientists and philosophers such as Al-Kindi (Alkindus), Al-Farabi (Alfarabi) and Abū Rayhān al-Bīrūnī.

The book proposes the theory that Venus is closer to Earth than the Sun.

Ibn Sina's theory on the formation of metals combines Jābir ibn Hayyān's sulfur-mercury theory from Islamic alchemy (although he was a critic of alchemy) with the mineralogical theories of Aristotle and Theophrastus.

He creates a synthesis of ideas concerning the nature of the mineral and metallic states.

Avicenna suggests a hypothesis about the origin of mountain ranges, and contributes to paleontology with his explanation of how the stoniness of fossils was caused.

Aristotle previously explained it in terms of vaporous exhalations, which Ibn Sina modified into the theory of petrifying fluids (succus lapidificatus).

Avicenna discusses the mind, its existence, the mind and body relationship, sensation, perception, etc.

He writes that at the most common level, the influence of the mind on the body can be seen in voluntary movements, in that the body obeys whenever the mind wishes to move the body.

He further writes that the second level of influence of the mind on the body is from emotions and the will.

He also writes that strong negative emotions can have a negative effect on the vegetative functions of an individual and may even lead to death in some cases.

Avicenna also gives psychological explanations for certain somatic illnesses, and he always links the physical and psychological illnesses together.