In the Name of Allah, the Most Gracious, the Most Merciful

Knowledge (al-`Ilm) is to comprehend the reality of something as it truly is, with certainty. The levels of comprehension are six:

  1. Knowledge (al-`Ilm) – which is to comprehend the reality of something as it truly is, with certainty. 1
  2. Slight/Simple Ignorance (al-Jahlul-Baseet) – which is absence of full comprehension. 2
  3. Aggravated/Compounded Ignorance (al-Jahlul Murakkab) – which is to comprehend something in a way contrary to its true reality. 3
  4. Delusion (al-Wahm) – which is to think that one comprehends something despite the presence of that which should cause you to realise that you are incorrect. 4
  5. Doubt (ash-Shakk) – which is to think that you comprehend something, yet you are aware of something contrary to it which you think has the same possibility of being the truth.
  6. Preponderant belief (Dhann) – which is comprehension of something, despite the presence of something which is contrary to it, but which is less likely to be true.

Knowledge (al-`Ilm) is of two categories:

  1. Inevitable (durooree)
    That which is known inevitably without any need to investigate or prove with the evidence, for example the fact that fire is hot.
  2. Speculative (nadharee)
    That which requires investigation and proof, for example the knowledge that it is obligatory to have intention (niyyah) when making ablution (wudoo)

[This is taken from Explanation of Three Fundamental Principles of Islaam by Sheikh Muḥammad Ibn Saalih al-`Uthaymeen]

  1. ^   For example, you see a sun and you have full knowledge of it’s attributes e.g, it is yellow in colour, it’s temperature is ~5600°c, it’s round in shape and it sets to prostrate to Allāh (subhanahu wa ta'ala) and seeks permission to rise again. This all falls under knowledge. The certainty comes with proofs and the first part of our example (colour, temperature etc) is established by science while the second part of our example (prostration and seeking permission) is established through authentic ḥadīth – see Sahih al-Bukhari 7424
  2. ^   Meaning to not understand something fully and you know you don’t know.
  3. ^   Meaning to be ignorant of something yet not be aware that you don’t know; you think you know everything so you act upon ignorance.
  4. ^   Meaning you do not realise that you are wrong.