Question : There are said to be six organs of different colours in the chest, of which the Heart is said to be two finger-breadths to the right of the middle line.But the Heart is also formless. Should we then imagine it to have a shape and meditate on it? Ramana Maharshi: No. Only the quest `Who am I?' is necessary. What remains all through deep sleep and waking is the same. But in waking there is unhappiness and the effort to remove it. Asked who wakes up from sleep you say `I'. Now you are told to hold fast to this `I'. If it is done the eternal being will reveal itself. Investigation of `I' is the point and not meditation on the Heart-centre. There is nothing like within or without. Both mean either the same thing or nothing. Of course there is also the practice of meditation on the Heart centre. It is only a practice and not investigation. Only the one who meditates on the Heart can remain aware when the mind ceases to be active and remains still, whereas those who meditate on other centres cannot be so aware but infer that the mind was still only after it becomes again active. In whatever place in the the body one thinks Self to be residing, due to the power of that thinking it will appear to the one who thinks thus as if Self is residing in that place. However, the beloved Heart alone is the refuge for the rising and subsiding of that `I'. Know that though it is said that the Heart exists both inside and outside, in absolute truth it does not exist both inside and outside, because the body, which appears as the base of the differences `inside' and `outside', is an imagination of the thinking mind. Heart, the source, is the beginning, the middle and the end of all. Heart, the supreme space, is never a form. It is the light of truth. Source: from David Godman Excellent Book "Be As You are"