Vedantasara - Verse 66
Sanskrit
मनो नाम सङ्कल्पविकल्पात्मिकान्तःकरणवृत्तिः
Swami Nikhilananda's Translation
The mind (Manas) is that modification of the internal instrument which considers the pros and cons of a subject (Sankalpa and Vikalpa).
Index: Vedantasara

Muni's Play