What is the Islamic opinion regarding other areas of knowledge, which may not be classified as Islamic knowledge, per se, but in fact are critical and necessary for the society’s functioning, such as medicine, dentistry, engineering and the likes of it?

The Prophet Muhammad (ﷺ) said: "God, His angels and all those in the Heavens and on the Earth, even ants in their hills and fish in the water, call down blessings on those who instruct others in beneficial knowledge." [1]

It is sufficient to know that knowledge can be divided into two categories:

• Individual obligatory knowledge (فرض عين): It is the knowledge of the Deen, to the degree necessary to be able to live a 24 hour day, doing that which pleases Allah. It is also knowledge of the rights and duties which are compulsory on a person and has to be done in its prescribed times, such as Hajj; a person is not required to know about it, until he is planning to perform the hajj. He may know about hajj in general, but as for the specific details about it, only becomes a necessity once the time for hajj has arrived.

• Community obligatory knowledge (فرض كفاية): It is that knowledge, which as long as some members of the community do it, then its obligation is removed from the others. This refers to knowledge of medicine, dentistry, etc. Therefore, if a person chooses to enter of the aforementioned fields of knowledge, then he should try to get as much knowledge as possible in that particular field, to fulfill the need of the community. If however, his community is a very basic group of people, and require the common types of medicine, for him to become a research scientist sitting in laboratory producing medicine for other societies, whilst his own Muslim community back home suffers by needing the same medicine, then he is going to an extreme; a person should have stopped at the point which he initially came for, otherwise he loses his way in glimpse of the success, forgetting about the community obligation. The Prophet (ﷺ) also said: "Knowledge from which no benefit is derived, is like a treasure out of which nothing is spent in the cause of God."[2]

References:

[1] Al-Tirmidhi, Hadith: 422

[2] Al-Tirmidhi, Hadith: 108