In man there are five senses. The sixth (sense) is the Mind. The seventh is called the Understanding. The Kshetrajna or Soul is the eighth.
इन्द्रियाणि नरे पञ्च षष्ठं तु मन उच्यते। सप्तमी बुद्धिमेवाहुः क्षेत्रज्ञः पुनरष्टमः॥