Association with the mean and the low inakes one's understanding mean and low; association with the indifferent makes it indifferent and association with the good makes it good.
बुद्धिश्च हीयते पुंसां नीचैः सह समागमात्। मध्यमैर्मध्यतां याति श्रेष्ठतां याति चोत्तमैः॥