The scholar recognizes the ignorant one because he (himself once) used to be ignorant, but the ignorant person is unable to recognize the scholar because he was never a scholar.“
وَالْعَالِمُ يَعْرِفُ الْجَاهِلَ؛ لِأَنَّهُ كَانَ جَاهِلًا وَالْجَاهِلُ لَا يَعْرِفُ الْعَالِمَ لِأَنَّهُ لَمْ يَكُنْ عَالِمًا؛
Ibn Taymiyyah, Majmūʿ al-Fatāwá 13/235
ابن تيمية، مجموع الفتاوى ١٣/٢٣٥