Mīmāmsa Sūtra 01.01.04

सत्सम्प्रयोगे पुरुषस्येन्द्रियाणां बुद्धिजन्म तत्प्रत्यक्षमनिमित्तं विद्यमानोपलम्भनत्वात् ॥४॥

Direct perception arises when the senses of a person come into contact with an existent object; this cognition is direct. Because it apprehends what is present, it fails to show the cause.