The text asserts "Pratyaksa" leads to "Laukika" or ordinary knowledge, where the five senses directly and clearly apprehend a reality, and this is true definite knowledge according to the text. It defines indefinite knowledge as one where there is doubt, and the text gives an example of seeing a distant stationary object in the evening and wondering whether it is a post or a man standing in the distance. In some of these cases, states Nyayasutras, correct knowledge is formulated by the principle of cumulative evidence. "Manas" (mind) is considered an internal sense, in the text, and it can either lead to correct or incorrect knowledge depending on how it includes, excludes or integrates information. These ideas are compiled, in later chapters of the text, into its treatise on "Aprama" (Theory on Errors).