4. The sciences (knowledge) of human beings and the sciences
(knowledge) of angels.
We observe in ourselves through sound intuition 21 the existence of three worlds.
The first of them is the world of sensual perception. We become aware of it by means of the perception of the senses, which the animals share with us.
Then, we become aware of the ability to think which is a special quality of human beings. We learn from it that the human soul exists. This knowledge is necessitated by the fact that we have in us scientific perceptions which are above the perceptions of the senses. They must thus be considered as another world, above the world of the senses.
Then, we deduce (the existence of) a third world, above us, from the influences that we find it leaves in our hearts, such as volition and an inclination toward active motions. Thus, we know that there exists an agent there who directs us toward those things from a world above our world. That world is the world of spirits and angels. It contains essences that can be perceived because of the existence of influences they exercise upon us, despite the gap between us and them.
Often, we may deduce (the existence of) that high spiritual world and the essences it contains, from visions and things we had not been aware of while awake but which we find in our sleep and which are brought to our attention in it and which, if they are true (dreams), conform with actuality. We thus know that they are true and come from the world of truth. "Confused dreams," on the other hand, are pictures of the imagination that are stored inside by perception and to which the ability to think is applied, after (man) has retired from sense perception.22
We do not find any clearer proof than this for (the existence) of the spiritual world. Thus, we have a general knowledge of it, but no particulars. The metaphysicians make conjectures about details concerning the essences of the spiritual world and their order. They call these essences "intellects." However, none of it is certain, because the conditions of logical argumentation as established in logic do not apply to it. One of these conditions is that the propositions of the argument must be primary and essential, but the spiritual essences are of an unknown essentiality. Thus, logical argumentation cannot be applied to them. Our only means of perceiving something of the details of these worlds are what we may glean from matters of religious law, as explained and established by religious faith.
Of the (three) worlds, the one we can perceive best is the world of human beings, since it is existential and attested by our corporeal and spiritual perceptions. The world of the senses is shared by us with the animals, but the world of the intellect and the spirits is shared by us with the angels, whose essences are of the same kind as the essences of that world. They are essences free from corporeality and matter, and they are pure intellect in which intellect, thinker, and the object of thinking are one. It is, in a way, an essence the reality of which is perception and intellect.
The sciences (knowledge) of the (angels), thus, always agree by nature with the things to be known. They can never have any defect. The knowledge of human beings, on the other hand, is the attainment of the form of the thing to be known in their essences, after it had not been there. It is all acquired. The essence in which the forms of the things to be known are obtained, namely, the soul, is a material substance 23 that gradually takes over the forms of existence with the help of the forms of the things to be known that it obtains. Eventually, it reaches perfection, and, through death, its existence fulfills itself as regards both its matter and its form.
The objects in the soul are subject to constant vacillation between negation and assertion. One of the two is sought by means of some middle (term) to connect the two extremes. When that is achieved and the object has become known, it must be explained that there exists agreement (between knowledge and the thing known). Such agreement may often be clarified by technical logical argumentation, but that is from "behind the veil," and it is not like the direct vision 23a that is found in connection with the sciences (knowledge) of the angels.
The "veil" may be removed, and the agreement may, thus, be effected through direct perceptive vision. It has been explained that human beings are ignorant by nature, because vacillation affects their knowledge. They learn through acquisition (of knowledge) and technique, because they obtain the objects they seek by applying their ability to think according to technical rules. The removal of the veil to which we have referred is achieved only through training in dhikr exercises 24 of which the best is prayer, which forbids sinful and evil actions-through abstinence from all distracting food of consumption - of which the most important part 25 is fasting - and through devoting oneself to God with all one's powers.
"God taught man what he did not know." 26