Ibn Taymiyyah says that all real existents can be known through hiss (sense perception), either outward (seeing, hearing, touching) or within (feeling pain, joy, love, etc.). What is unseen now may be seen later.
The Salaf held that Allah can be seen in the Hereafter, and that angels and jinn are real, perceptible beings, not just in the mind.
The philosophers (like Ibn Sina) divided existence into two: sensible (perceived by the senses) and intelligible (universals in the mind only). They denied that unseen beings like angels and jinn exist in external reality, saying they exist only in the perceiver’s mind.
Ibn Taymiyyah refutes this, saying that unseen beings are known by authentic hadiths, by tawatur, and by experiences of prophets and others who witnessed them. An example would be the honoured guests of Ibrahim عليه السلام, their glad tidings to Sarah, and their destruction of the people of Lut عليه السلام, as Allah mentioned. Also, the story of Maryam عليها السلام and Jibril عليه السلام coming to her, and Jibril coming to the Prophet ﷺ sometimes as a Bedouin and sometimes as Dihya al-Kalbi رضي الله عنه. Sense perception is broader than just bodily senses, since the spirit perceives things the body cannot.
The shayk criticises the philosophers for reducing human perfection to abstract knowledge of universals. They denied the certainty of practical truths (mashhuraat), denied unseen realities, and stripped deeds from having value. In their view perfection is just knowledge, not love of Allah or righteous action.
His conclusion on them is that their “knowledge” is mostly ignorance, because it does not deal with real existents but with mental abstractions. They missed the true path of knowledge and deeds that bring salvation, so even Jews and Christians were closer to salvation than them.
It is known from the madhhab of the Salaf and Ahl al-Sunnah wa al-Jamaah that Allah can be seen in the Hereafter, and that angels and jinn can also be seen, and that the attributes connected to what is seen can be known through it, just as sounds are known through hearing and tangible things through touch.
They say: The messengers, peace be upon them, divided what exists into ghayb (unseen) and witnessed, and commanded mankind to believe in what they informed about of the unseen.
The distinction between what is witnessed and what is ghaib (absent) returns to whether it is witnessed now or not witnessed now. If it is not witnessed now, it may be witnessed later. This is unlike those who deny, for they divided what exists externally into mahsus (sensible), and into ma’qul (intelligible) that cannot be sensed, which is impossible.
This is something denied by sound aql, not affirmed by it. The purely ma’qul is only that which is fixed in the mind, like universal knowledge.
Universals have no existence outside the mind. Yet it may also be said: they can be sensed if their locus can be sensed, just as other a‘rad (attributes or accidents) can be sensed, such as ilm (knowledge), qudra (power), irada (will), and so on.
But we do not sense these things now through the hiss dhaahir (outward sense). Our lack of sensing them now does not prevent angels from being able to sense them, nor does it prevent us from sensing them in another state.
It is also possible for one to sense what is in the batin (inner self) of another, just as one senses his own face and eyes, though a person does not see his own face and eyes directly. A person may witness from another what he does not witness from himself. The discussion on these matters has been expanded elsewhere.
Also, hiss (sense perception) is of two types: hiss dhaahir (outward sense), by which a human perceives with his outward faculties, seeing, hearing, and touching with the skin, and hiss batin (inward sense), as when a human feels within himself ladhdha (pleasure) and pain, love and hate, joy and sorrow, strength and weakness, and so on.
The ruh (spirit) senses things that the body does not sense. For example, one who attains a state of partial tajrid (detachment), through sleep or otherwise, perceives matters that others do not perceive. Then the ruh after death becomes even more detached, so it sees and perceives after death matters it does not see or perceive now.
Among people there are those whose state causes them to see with their eyes and hear with their ears what others present do not see or hear, as the anbiya (prophets) see angels and hear their speech, and as many people see the jinn and hear their words.
As for what some philosophers say, that these seen and heard things exist only in the self of the perceiver and not in external reality, this is known to be false by many proofs. The discussion on this has also been expanded elsewhere.
One who has some experience with the jinn, either through direct encounter himself or among others, or through reports that have reached him by tawatur (mass-transmission) from people, knows with certainty of their existence externally, apart from what has come by tawatur from the anbiya.
Likewise, what has come by tawatur from the anbiya about the description of angels brings certain knowledge of their existence externally, such as the story of the honoured guests of Ibrahim, their coming to him, his bringing to them the fat calf to eat, their giving glad tidings to Sarah of Ishaq and Yaqub, then their going to Lut, speaking to him, and destroying the towns of the people of Lut. Allah has related this story in more than one place.
Also the story of Maryam, and Allah sending to her Jibril in the form of a man so that he breathed the ruh into her, and the story of Jibril coming to the Prophet, peace and blessings be upon him, sometimes in the form of a Bedouin, and at times in the form of Dihya al-Kalbi.
Whoever knows that the ruh may sense what the body does not sense, and that some people sense with their ruh and body what others do not sense, then the ways of hiss (sense perception) are broadened for him. He will not see hiss as restricted to what most people perceive in this worldly life with their bodies, for this hiss perceives only some existents.
Thus, if it is said: Everything existing by itself, or every existent, can be perceived through hiss, then what is meant is in the general sense of perception, which includes this and that. Those who deny have no proof for affirming what is not sensed by this hiss. The rational things they affirm are only kulliyyat (universals) fixed in the mind, which in truth exist in the minds, not in external reality.
This is the furthest point reached by Ibn Sina (d. 428 AH) and others among the falasifa. Hence for them the perfection of man is to become an aql ma‘qul (rational intellect) corresponding to the existing universe. They made na‘im (bliss) and adhab (punishment) matters subsisting in the nafs (soul) as part of its attributes, not separated from it. We have explained elsewhere some of the misguidance in this claim.
For this reason, in his mantiq (logic) he made the certain intellectual sciences only these rational universals. He denied that mashhuraat (commonly accepted truths) in practice are among the certainties. He denied that knowledge of unseen existents known through hiss is among the certainties, and he named these wahmiyyat (imaginations).
By denying this, he denied the ghaybiyyat (unseen existents) that are absent from the hiss of most people in this worldly life. Thus he did not affirm the ghaybiyyat, nor much of what is witnessed in this universe of angels, jinn, and other things.
By denying that mashhuraat are certain, he denied the function of the quwwa amaliyya (practical faculty) in the nafs by which it judges as good the actions that benefit it and judges as bad the actions that harm it. He removed a‘maal (deeds), which are essential to the perfection of the nafs, from being certain, just as he removed them from being part of perfection. He did not make the perfection of the nafs anything but mere abstract knowledge, without true mahabbah (love) of Allah. In their view deeds are only for preparing the nafs to obtain what they imagine as perfection in knowledge.
Yet this knowledge which they claim is mostly ignorance, and what knowledge exists within it is not knowledge of mawjudat muayyana (specific existents), but rather knowledge of abstract matters in the mind with no existence outside.
They did not obtain from knowledge and amal (deed) the perfections that bring about saadah (happiness) in the Hereafter and najat (salvation) from the Fire. Many Yahud (Jews) and Nasara (Christians) were closer to saadah and najat than them, as has been explained elsewhere.
For this reason, in his mantiq he made the certain intellectual sciences only these rational universals. He denied that mashhuraat amaliyya (practical common truths) are among the certainties. He denied that knowledge of unseen existents known through hiss is among the certainties, and he named these wahmiyyat.
By denying this, he denied the ghaybiyyat absent from the hiss of most people in this worldly life. Thus he did not affirm the ghaybiyyat, nor much of what is witnessed in this universe of angels, jinn, and other things. By denying that mashhuraat are certain, he denied the function of the quwwa amaliyya in the nafs by which it judges as good what benefits and bad what harms. He removed a‘maal, which are necessary to the perfection of the nafs, from being certain, just as he removed them from being perfection.
He did not make the perfection of the nafs anything but mere abstract knowledge, without true mahabbah of Allah. In their view a‘maal are only to prepare the nafs for what they imagine is perfection in knowledge.
This knowledge they claim is mostly ignorance, and what is in it of knowledge is not knowledge of mawjudat muayyana, but only knowledge of abstract matters in the mind with no existence outside. Therefore they did not attain from knowledge and a‘maal the perfections that bring saadah in the Hereafter and rescue from the Fire. Many Yahud and Nasara were closer to saadah and najat than them.
Darʾ taʿāruḍ al-ʿaql wal naql (6/107-112)
