Knowledge is of two types. Divine, which is the Qur’ān and Sunnah, and secular, which is the worldly sciences. So, we ask you, our virtuous scholar, which of the two is obligatory upon every Muslim to learn, and which of them is a communal obligation?
Shaykh Muqbil bin Hādī al-Wādiʻī:
All praise is due to Allāh, the Lord of all creation, and may Allāh send his peace and blessings upon our Prophet Muḥammad, his followers, and companions. And I testify that none has the right to be worshipped in truth except Allāh alone, without a partner, and I bear witness that Muḥammad is his servant and messenger.
To proceed, knowledge of the religion in and of itself comprises of whatever is obligatory upon everyone to know, and also whatever is a communal obligation.
Whatever is obligatory upon everyone, is in reference to the statement of the Prophet ﷺ “Seeking knowledge is obligatory upon every Muslim”. Which entails, studying what Allāh has obligated upon you from correct belief, and understanding the prayer of Allāh’s Messenger ﷺ.
If it were obligatory for you to perform Ḥajj, then upon you is to do so as the Prophet ﷺ did it due to his saying, “Learn your Ḥajj rites from me”, collected by Muslim. And in An-Nasā’ī “Take your Ḥajj rites from me”. Likewise, if one intends to sell or purchase goods, then it is obligatory upon him to learn the rulings of buying and selling so that he does not fall into taking interest nor unlawful trade.
Therefore, the action you engage in makes it obligatory upon you to learn Allāh’s ruling regarding it. Whether that be acts of worship, beliefs, or transactions.
From knowledge, are aspects considered virtuous, but not obligatory, and therefore, they become a communal obligation.
Whomsoever Allāh favours with understanding and good memory, yet he abstains from and abandons beneficial knowledge, then he is at loss. Just as Al-Ḥāfidh al-Khaṭīb mentioned in his book “The Jurist and The Student.”
As for secular knowledge, then it is a communal obligation, but only after the Muslim gains understanding of Allāh’s religion.
“There should remain from each tribe a group in order to obtain an understanding of the religion and warn their people when they return to them so that they might be cautious” [At-Tawbah:122]
The Prophet ﷺ mentioned, as comes in the Ṣaḥīḥayn, from the narration of Mu’āwiyah, “Whomsoever Allāh wants good for, then he grants him understanding of the religion.”
However, learning what the Muslims require from the affairs of politics, manufacturing weaponry, medicine, engineering, and other than that, could be a communal obligation after one fulfils what Allāh has obligated upon you from individual obligations, and Allāh’s aid is sought.