Another example is “word”...

Another example is “word”, which with regard to changes which occur in its construction becomes the subject of the science of morphology, and with regard to the changes in inflection it becomes the subject of the science of syntax. Therefore, one should be careful about whether the inclusive topic is the subject of a certain science absolutely, or with specific restrictions and qualifications.

How often an inclusive topic becomes the subject of a general science absolutely, and then with the addition of restrictions it takes the form of subjects for specific sciences. For example, in the well known classification of philosophy according to the ancients, body is the subject of all the natural sciences, and by adding restrictions it takes the form of the subjects of mineralogy, botany and zoology, etc.

Regarding the quality of the branches of the sciences, it was indicated that some divisions are obtained by restricting the scope of a subject and by adding qualifications to the topic of the mother subject.

Among the possible qualifications to add to the topic of the subject is “the restriction of absoluteness” ( qayd iṭlāq ), which means that in that science principles are discussed which are proved for the essence of the subject generally, or absolutely, without considering any specific characteristics. In conclusion, it is to include all individuals of the subject.

For example, the principles and qualifications are established for body in general, absolutely, whether mineral or organic, whether vegetable or animal or human. In this way one can determine the subject to be “absolute body”, and this sort of problem may be further specified to specific sciences.

The sages have thus specified the first section of physics to cover such principles with the names samā‘ ṭabī‘ī (elementary general physics) and samā‘ al-kiyān (elementary general astronomy), then they specified the groups of bodies for specific sciences such as cosmology, mineralogy, botany and zoology. This same work can be done for more particular subdivisions of the sciences.

For example, the problems related to all animals can be taken as a specific science whose subject is the animal, absolutely, or animal qua animal. Then specific principles may be discussed for each kind of animal in other more specialized sciences.