Thought processes and mental events are conscious only to the extent they receive illumination from Purusha. In Samkhya, consciousness is compared to light which illuminates the material configurations or 'shapes' assumed by the mind. So intellect, after receiving cognitive structures from the mind and illumination from pure consciousness, creates thought structures that appear to be conscious. Ahamkara, the ego or the phenomenal self, appropriates all mental experiences to itself and thus, personalizes the objective activities of mind and intellect by assuming possession of them. But consciousness is itself independent of the thought structures it illuminates.
See the venn diagram of Purusha and Prakriti at - https://en.wikipedia.org/wiki/Samkhya#Philosophy
Relevant Excerpt:
Thought processes and mental events are conscious only to the extent they receive illumination from Purusha. In Samkhya, consciousness is compared to light which illuminates the material configurations or 'shapes' assumed by the mind. So intellect, after receiving cognitive structures from the mind and illumination from pure consciousness, creates thought structures that appear to be conscious. Ahamkara, the ego or the phenomenal self, appropriates all mental experiences to itself and thus, personalizes the objective activities of mind and intellect by assuming possession of them. But consciousness is itself independent of the thought structures it illuminates.