From Shaykh Aḥmad al-Dardīr’s commentary on Al-Kharīdah al-bahiyyah:
والعلم من حيث إنه علم لا ينجي من عذاب اللَّه ما لم يعمل به، والعبادة المطلوبة شرط صحتها العلم، فينبغي للعاقل أن يقتصر من العلم على ما به العمل، وهو العلم الشرعي، وهو ثلاثة أنواع: علم أصول الدين، وعلم الفقه، وعلمالتفسير، وما يتصل بذلك من آلاتها كعلم النحو والمعاني والبيان، بخلاف علوم الفلاسفة فإنها باطلة إن سلم صاحبها من الضلال، وإلا فهي عين الوبال. نعم علم الطب وما يوصل إلى معرفة الوقت والجهات من علم النجوم فذلك جائز، على أنا لا نسلم أن هذا من علم الفلاسفة، بل هو من الشرعي، بدليل ﴿وَهُوَ الَّذِي جَعَلَ لَكُمُ النُّجُومَ لِتَهْتَدُوا بِها فِي ظُلُماتِ الْبَرِّ وَالْبَحْرِ﴾ [الأنعام: الآية ٩٧]، والإذن بالطب مشهور في السنة.
Knowledge, insofar as it is merely knowledge, does not save from Allah’s punishment unless it is acted upon. The validity of the required worship depends on knowledge, so it is appropriate for the intelligent person to limit themselves to the amount of knowledge that leads to action—namely, religious knowledge (ʿilm sharʿī). This encompasses three types: knowledge of the foundations of religion (ʿilm uṣūl al-dīn), knowledge of jurisprudence (fiqh), and knowledge of exegesis (tafsīr), along with the necessary tools for these fields, such as knowledge of grammar (naḥw), semantics (maʿānī), and rhetoric (bayān). This is in contrast to the sciences of the philosophers, which are invalid, even if their practitioners are free from misguidance; otherwise, they are the essence of ruin.
However, the science of medicine (ṭibb) and knowledge that leads to determining time and directions based on astronomy (ʿilm al-nujūm) are permitted. Yet we do not concede that these belong to the philosophers' sciences; rather, they are part of the religious sciences, as indicated by the verse, “And it is He who made the stars for you to guide you through the darknesses of land and sea” [Al-Anʿām, 6:97]. Permission for practicing medicine is also well-established in the Prophetic traditions.
— n.b. To keep things simple: Shaykh al-Dardir is addressing Muslims living in a fairly ideal state. He is not addressing Muslims living in a state where their understanding of the world is already corrupted by ideas foreign to and incompatible with sound Islamic beliefs. We live in the latter. Sound philosophy starts with sound aqidah and sound aqidah is a personal duty. So sound aqidah needs to be learned before delving into philosophy as a whole—an aqidah that covers philosophical issues that are common today.
