Iqbal confronts the mind-body problem and refuses the Cartesian split. Reading the Qur'anic creation verses in Sūrah al-Muʾminūn, he proposes that the body is 'accumulated habit of the soul' and that matter itself is a colony of low-order egos — the human ego being what emerges when these achieve sufficient coordination. The result is a panpsychist emergentism in which the Ultimate Ego is immanent in the very process that produces higher forms of selfhood.
Section 5 established the ego's nature as directive energy rather than static substance — 'my real personality is not a thing; it is an act' — and grounded this conception in the Qur'anic distinction between Khalq (creation of the extended world) and Amr (direction, the mode of divine activity that produces ego-unities). But this account immediately raises a further question: if the ego belongs to the order of Amr and the body to the order of Khalq, how does the ego emerge within the physical, spatio-temporal world? And what is the relationship between the directive ego and the physical organism it inhabits? Section 6 confronts this question — the mind-body problem — and offers one of the most ambitious metaphysical arguments in the entire Reconstruction.
The section advances through three major movements. First, Iqbal turns to the Qur'an's account of human creation in Sūrah al-Muʾminūn (23:12–14), which describes a graduated series of physical transformations — clay, germ, clot, flesh, bones — culminating in the phrase 'then brought forth man of yet another make.' This 'yet another make' is the emergence of the ego: something genuinely new that arises from the physical sequence but is not reducible to it. The body, Iqbal proposes, is 'a colony of sub-egos' through which a deeper Ego acts — not a dead mechanism but a coordinated community of low-order experiential centres.
Second, Iqbal surveys the classical Western responses to the mind-body problem. Cartesian dualism posits two independent substances — mind and body — but cannot explain their interaction. Leibnizian parallelism avoids the interaction problem by denying that mind and body affect each other at all, but reduces the soul to a passive spectator. Interactionism asserts that mind and body do affect each other, but cannot specify how or where the interaction occurs. Iqbal engages Carl Lange's theory of emotion as a test case, arguing that even where the body initiates, the mind's consent — its act of attention — is the decisive factor. Neither parallelism nor interaction is satisfactory.
Third, Iqbal offers his resolution. Mind and body are not two substances but two systems of acts that belong to a single creative order — united under the Qur'anic formula 'To Him belong Khalq and Amr.' The body is not alien matter mysteriously attached to the soul; it is 'accumulated action or habit of the soul' — the sedimented history of the ego's own directive activity, appearing from the outside as something stable. Matter itself, at its deepest level, is 'a colony of egos of a low order,' and the human ego is what emerges when these low-order centres achieve a sufficient degree of coordination. The section culminates in an embrace of Emergent Evolution: the higher is not diminished by arising from the lower; it is an 'unforeseeable and novel fact on its own plane of being.' The Ultimate Ego that drives this emergence is immanent in nature — not a transcendent God who intervenes from outside but the creative reality described by the Qur'an as 'the First and the Last, the Visible and the Invisible.'
This is the most scientifically and metaphysically ambitious section of Lecture IV so far. It stakes out a position that is simultaneously anti-dualist (against Descartes), anti-materialist (against the reduction of mind to matter), and anti-interventionist (against the idea of a God who must inject soul into inert matter from the outside). The position is a form of panpsychist emergentism: reality is experiential all the way down, and the human ego is the highest expression of a creative tendency that pervades the entire natural order.