Kitâbü’ş-Şifâ: Nefs

The theory of the soul, as it is presented in the texts of classical philosophers, is a theory that tries to explain how vitality and movement are attached to existence and human beings, and how the relationship between the soul and the body is established. The basic claim of the theory finds its expression in the propo- sition ‘The soul is an immaterial, incorporeal, independent and immortal substance’, which is a Platonic claim in its origin. These two basic claims, (i) that the soul is an immaterial, incorporeal, and independent substance and (ii) that the soul is an immortal substance, both reveal the basic concepts of the theory of the soul and play a decisive role in shaping its sub-problems. The concepts put forward in the proposition ‘The soul is immaterial, incorporeal and independent substance’ are the soul, immateri- ality, incorporeality and independent substance. The proposition ‘The soul is an immortal substance’ reveals the concept of im- mortality. These two propositions determine the basic problem areas that constitute the whole theory of the soul. Ibn Sīnā, the philosopher who gave the theory of the soul its most complete form in the Islamic philosophical tradition, put forward his theory in five articles in the sixth science of the section on the physical sciences of the Kitāb al-Shifāʾ. Ibn Sīnā examines in the first article, the proof of the soul, the substance of the soul, and the powers of the soul in general; in the second article, the powers of the vegetative soul and the senses of touch, taste, and hearing specific to the animal soul; in the third article, the sense of sight; in the fourth article, the internal senses; and in the fifth article, the powers of the human soul. Throughout these five articles, Ibn Sīnā primarily addresses the following problems in relation to the first of the two basic propositions stated above: 1. The definition and nature of the soul and the justification of the soul as a substance independent and distinct from the body and the soul-body dualism, which is based on issues such as the flying man and self-consciousness. 2. The nature of the relations and interactions between the soul and the body, between soulish states and bodily states, and how they are realised. 3. The dif- ferentiation of the soul’s faculties and actions and religious or mystical phenomena such as imagination, prophecy, revelation, dream, divine intellect, intuition and miracle as the background of the relationship and interaction between the soul and the body. 4. A fourth problem that Ibn Sīnā analyses in relation to the second proposition are issues such as the immortality of the soul after its separation from the body, its individuality, and re- incarnation. Ibn Sīnā’s Kitāb al-nafs is noteworthy as a competent philosoph- ical analysis of the soul written in the classical age of Islamic philosophy, which was highly influential not only in Islamic philosophy but also in the history of philosophy in general for a long time. Written as part of the most comprehensive and all-encompassing philosophical corpus of the period in which it appeared, the work attempts to provide a reasonable and holistic framework for how all kinds of biological, physical, bodily, senso- ry and mental vital activities of human beings are realised. The basic problems analysed in the book continue to be discussed in the philosophy of mind, even nowadays when we are in a com- pletely different historical situation, under the titles such as ‘the mystery of consciousness’ or ‘the hard problem’. In this respect, Ibn Sīnā’s work is a difficult but seminal work that is completed at the literal level, as one would expect from a classical text, but constantly awaits reinterpretation at the problematic level.