Question: But in this case, how can we meditate on the heart? We don't even know where it is.

Sri Chinmoy: It depends on whose path you follow. If one Master says the heart is here, and you want to follow his path, then this is where you meditate. If you do not have anyone as your teacher, then go deep inside and do not even concentrate on the heart. Only concentrate and meditate on Light. Then, one day, during your meditation, you will receive Light here, or here, or here, or here. So just meditate on the Source and eventually the location will come to you. If you follow a specific path, then you have to have implicit faith in what your Master says. But if you are not sure, if you say, "I do not follow any path I am just curious to know where the heart is," then I wish to tell you not to bother about the location. Only think of the things that the heart can give: Peace, Joy, Love, Bliss, Light. Think of the quality and not of the location. When you meditate on the quality, the quality itself will come to the fore, and this is the important thing. Concentrate on the Source and the Source will bless you so that illumination can take place. Then you can observe the location from which the flow comes. I tell my disciples not to fight about right or left, but only to think of love, devotion and surrender. Love God with your entire existence, devote yourself to God with your entire existence, surrender yourself to God. Love, devotion and surrender will show you everything.