Vaisesika Sūtra 10.1.02

संशयनिर्णयान्तराभावश्चज्ञानान्तरत्वे हेतुः ॥२॥

saṁśaya-nirṇaya-antara-abhāvaś ca jñānāntaratve hetuḥ ॥2॥

[संशय (saṁśaya) - doubt; निर्णय (nirṇaya) - determination; अन्तर (antara) - distinction; अभावः (abhāvaḥ) - absence; च (ca) - and; ज्ञानान्तरत्वे (jñānāntaratve) - in the case of difference in knowledge; हेतुः (hetuḥ) - is the reason;]

Due to the differences in the ability to arrive at a conclusion, because of doubt or its absence, knowledge varies.