Many say that (1) the mind (ie. thoughts) cannot be controlled and (2) the mind need not be controlled for liberation to result. Here is what is written in the Bhagavad Gita, chapter 6, verses 35 and 36:
Arjuna: The mind is very restless, turbulent, strong and obstinate, O Krishna. It appears to me that it is more difficult to control than the wind.
Lord Krishna said: O mighty-armed son of Kunti, what you say is correct; the mind is indeed very difficult to restrain. But by practice and detachment, it can be controlled.
Note the teaching here is clear – the mind can be controlled. Just practice is required. To find out more, please read Chapter 6 of the Bhagavad Gita which explains the meaning of ‘controlling the mind’, the method of doing so, and the result (Moksha)