From After Awakening, Chapter 5;
The famous sage Ramana Maharshi when asked the question, ‘How can we assess our progress on the spiritual path?’ purportedly replied, ‘Freedom from unwanted thinking, and the ability to concentrate one’s attention on an object without distraction.’
The crucial point for this discussion is that he stresses ‘unwanted thinking’, as opposed to a ‘silent mind’. Much of the unhealthy self-referential repetitive thought could be described as ‘unwanted’ thinking as it veils the inherent peace and takes energy away from our attention in the moment. (We can also observe that as the mind becomes ‘unified’ the ability to use ones intention and attention undistracted also increases).