Sanskrit: कारणं व्यतिरेकेण पुमानादौ विलोकयेत्।  अन्वयेन पुनस्तद्धि कार्ये नित्यं प्रपश्यति।   
English:  One should first look for the cause by the negative method and then find it by the positive method, as ever inherent in the effect.