Sri Chinmoy: If it is your real heart, then you will get a sense of satisfaction, pure satisfaction. If it is the mind you may also get satisfaction, but immediately you will also get something else and that some thing else is doubt. Your experience will be attacked by other thoughts: "How can I have this kind of satisfaction? I am so bad, I am so impure, I am so ignorant. This morning I told a lie and yesterday I did something very wrong, so I cannot have this kind of satisfaction." When that kind of idea comes, then you will know that your experience was from the mind. When you get an experience with the mind, you may temporarily feel very happy, delighted. But you won't be able to establish your identification with what the mind has seen or felt or realised.
But once you get an experience from the heart, immediately you feel your oneness with it. When you see something with the heart, you get joy and immediately you are one with it. When you see a flower with your mind, you appreciate and admire it. But when you see it with your heart, immediately you feel either that your heart is inside the flower or that the flower is inside your heart. So when you have an experience and feel a kind of satisfaction, if you feel that you are one with the experience itself, then you will know that it is from the heart. But if you feel that the experience is something outside you that you are achieving, then it is from the mind.