An acquaintance likes to relate the following self-deprecating anecdote: when he was a young Yeshivah student, he used to observe a certain אדם גדול smoking. Meaning to be friendly, he comfortingly remarked “Nu, שומר פתאים השם”, assuming that פתאים meant something like צדיקים or חסידים. When he subsequently learned the true meaning of the word, he was greatly chagrined at having insinuated that the אדם גדול was a fool.
The lesson the raconteur derives from this story is merely a warning of the potential pitfalls of bandying about phrases which one doesn’t fully understand, but I recently learned that there’s actually a significant Halachic issue at stake here.
Rav Yisrael Isserlin, discussing the principle of שומר פתאים השם as it potentially applies to a קטלנית, remarks1:
וצריך עיון אי שייך למימר האי טעמא שומר פתאים לתלמיד חכם שהוא יודע ומכיר ונזכר למופלא בדורו
He seems to be suggesting that great תלמידי חכמים don’t fall under the rubric of שומר פתאים השם; I don’t know if Poskim make this point in other contexts of Halacha where this principle occurs.
One might argue, though, that this distinction between תלמידי חכמים and ordinary people is only relevant for סכנות which are Talmudic in origin; perhaps there’s no difference in the context of smoking, the danger of which is known through medical science.
- שו”ת תרומת הדשן סימן רי”א