To explain...

To explain, just as each of our senses is able to perceive one of the features of bodies (for example, our eyes see its color, our olfactory sense smells its scent, and our gustatory sense perceives its taste) without removing the unity of the body which possesses all of these senses, in the same way, it is possible that there may be a multiplicity in bodies which our senses do not have the power to perceive.

In other words, the unity and multiplicity of sensory perceptions does not provide sufficient reason for the unity and multiplicity of entified existence. Hence, there remains the possibility that a body which itself has geometrically continuous unity possesses another multiplicity, as some philosophers have held with respect to different substantial forms, for example, an animal is known to possess several forms vertically: an elemental form, a mineral form, a vegetable form and an animal form.

The answer to this question is to be found in the ensuing lessons, and here we may say in summary form that the composition of bodies can be imagined to takes several forms: Composition of quantitative parts which do not have actual existence, but which come about as a result of analysis. This kind of composition is not at all contrary to actual unity. Composition of matter and form, under the supposition that the existence of matter is a potential existence.

This form also does not interfere with unity, and from one view it is similar to the previous supposition. Composition of matter and form, under the supposition that matter also has actual existence other than the existence of the form. Also, composition among forms each of which is vertically above the other.

According to this supposition, an existent is considered a unit because of the unity of its highest form, and is related to all of them by accident, and it would be better to call them ‘unified’ rather than a ‘unit.’ Composition among several actual existents which are on one plane horizontally and none of which is a form higher than the others, even if some kind of continuity and connection exists among them, such as the composition of the parts of a clock and other machines, which is called ‘mechanical composition.’ Under this assumption, the composed collection cannot be considered as a ‘unit’ or even ‘unified’ from a philosophical point of view; rather it must be construed as multiple existents, and as possessing a conventional ( i‘tibārī ) unity.