Is it a condition for a فقيه (jurist) to be an أصولي (master of Islamic legal methodology), or vice versa?

A jurist (faqih) cannot be a jurist unless he is an expert in legal methodology (usuli), for fiqh (jurisprudence) originally means understanding, and a jurist in technical terms is a scholar of Sharia who has understood its objectives. The term may be applied metaphorically to someone of a lower rank. The mujtahid (independent jurist) has conditions, the most important of which is knowledge of the usul (foundations/principles), such as the chapter on qiyas (analogical reasoning), because it is through qiyas that most emergent issues and new cases are understood. Al-Walati said: "Qiyas is the wellspring of fiqh, from which branches and the science of disagreement diverge." By knowing the usul al-fiqh, the verses of rulings and their corresponding hadiths, and their abrogating and abrogated texts, the usuli becomes a jurist if he possesses the natural aptitude. Fiqh and usul are intertwined, and one who has no share of usul cannot truly be described as a jurist.