Someone sent me this, from Imam Ahmad Zarruq’s Principles of Sufism:

Principle 41

Blind conformisn (taqlīd) is the acceptance of a teaching without
regard to the reputation of the teacher or to the methodology of the
teaching. It is absolutely objectionable because the person of blind
conformism is making a mockery of his religion. Emulation (iqtidā’) is
the acceptance of a teaching by taking in to consideration the
religiosity of the teacher and his knowledge. This is the method of the
jurisconsults of the schools of jurisprudence in following the founders
of their schools. Calling emulation “blind conformism” is figurative speech.

Discernment (tabaṣṣur) is the acceptance of a teaching by virtue of its
specific proof without being self-opinionated or disregarding the
teaching at its face value. This is the method of the masters of the
schools of jurisprudence and of the elite among the seekers of
religious knowledge.

Independent judgement (ijtihād) is proposing rules based on proofs
without reference to other authorities; then, if no previous principle
is to be considered as a precedent, the judgement is obsolute;
otherwise, it is limited.

A school of jurisprudence is that which grows stronger in a person’s
soul until he follows it. The general meaning of the above has been
mentioned in Miftāḥ al-Sa’ādah.