Is it obligatory for a Muslim to be knowledgeable in all Islamic sciences, such as the science of Hadith terminology and the principles of Islamic jurisprudence?

It is not obligatory for every Muslim to learn the terminology of Hadith (mustalah al-hadith) and the principles of Islamic jurisprudence (usul al-fiqh). Rather, it is obligatory for him to learn the individual obligations (furood al-ayaan) such as knowledge of Allah and His Messenger, prayer, ablution, and zakat for those who possess wealth. The Hadith: "Seeking knowledge is an obligation upon every Muslim," is interpreted in this sense. As for sciences like Hadith terminology, principles of Islamic jurisprudence, and similar fields, it is required for the Mujtahid (independent jurist) to know them. He must be a Muslim, a responsible adult (mukallaf), possess sound understanding, and be knowledgeable of the sources of rulings, the abrogating and abrogated verses, the Arabic language, and the principles of Islamic jurisprudence, so that he does not issue fatwas without knowledge.