Valmiki Ramayana Ayodhya Kanda Sarga 100 Shloka 39
Original Shlokaधर्मशास्त्रेषु मुख्येषु विद्यमानेषु दुर्बुधाः। बुद्धिमान्वीक्षिकीं प्राप्य निरर्थं प्रवदन्ति ते।।2.100.39।।
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दुर्बुधाः these superficial fellows, मुख्येषु among the principal, धर्मशास्त्रेषु in scriptures, विद्यमानेषु while existing, आन्वीक्षिकीम् relating to the science of logic, बुद्धिम् intelligence, प्राप्य having obtained, निरर्थम् futile, प्रवदन्ति argue.
While principal scriptures do exist, these superficial fellows take resort to the science of logic based on abstract reasoning, and indulge in futile talks.