Ashtavakra Gita 11.5 -

The Sage earlier spoke about desire and imagination as the cause of misery; here he brings concern as the cause. Desire, concern, possessiveness, ownership and the like are all thought-processes initiated by the mind. Whatever be the variation in thought, its effects are the same – a disturbance and agitation. Both are afflicting. Being confirmed in this makes the mind free, concernless.

So, discreetly bid goodbye to all kinds of thought-process, as Sage Vasishtha told young Rama in the Ayodhya palace: “All along, dear Rama, you have been indulging in saṅkalpa, thought-process. Enough of it. Leave it all, attain the doubtless nir-vikalpa state and derive the quietitude you yearn for.”

Ever since the mind and the senses began to perceive the plural world, crisscross thoughts and imaginations gripped it and began to rule its deliberations. And you know, what is the outcome.

In the same manner, the mind can be wisely led to recede from all thought-processes and reflect upon the Self, the sole Subject. If the first is an extrovert habit, the next is an introvert pursuit. As the former was effective, the latter too will be. It is all a question of pursuing Self-introspection. The whole spiritual pursuit consists in dexterity and astuteness in leading the mind to truthful and infusional introspection. Once the seeker takes it up, it will be more effective than worldly deliberations and their adverse effect.