They are characterised by outgoing tendencies on account of the force of Rajas. They are in their nature so constituted that they run towards external objects. They cannot cognise Brahman. Knowledge of Brahman cannot come through mere reasoning. You can attain this knowledge through intuition or revelation.
Intuition is the final result of the enquiry into Brahman.
The object of enquiry is an existing substance. The Brahmakara Vritti is generated from the Sattvic Antahkarana which is equipped with the four means of salvation, and the instructions of the Guru, who has understood the real significance of Tat Tvam Asi Mahavakya. This Brahmakara Vritti destroys the Mula-Avidya or primitive ignorance, the root cause of all bondage, births and deaths. When the ignorance or veil is removed, Brahman which is self-effulgent reveals Itself or shines by Itself in Its pristine glory and ineffable splendour. In ordinary perception of objects the mind assumes the form of the object.