Intellect is our nearest part to Chetan (consciousness). Knowledge and light (illumination) are the expressed characteristics of Shree Bhagwan. Intellect inspires understanding in many kind of worldly affairs. Sometimes intellect does not inspire understanding like the light of the sun. The reason being, intellect gets covered by karma and Prakruti. Our intellect is guided and inspired by many kinds of wishes, expectations and covetousness. For this reason, intellect is not completely Satwik. There is no Samata (equanimity) and Tatasthata (balanced attitude) in intellect so intellect fails to find the solution of the problem. Otherwise real nature of Intellect is knowledge-illumination. If there is Samata in Intellect, it can solve any problem. As long as it is guided by many kinds of attachments-hate, it cannot provide clear answer of the problem to us. To get the answer, we need to purify the intellect.
Pujya Shree Mota
Jivan Yog, Part 1
Edition 1, Page 355.