The heart means love. A good heart means love to the Lord and to the neighbor, while a hard or stony heart means the love of self or the world -- riches and things. When the psalmist asks the Lord to search his heart, he wants the Lord to see what it is that he loves. And we are what we love. What we eat may form our earthly body, but it's only temporary, what we love forms our spiritual body, beautiful or ugly as we have chosen. It's interesting to note that the first multi-cellular motion of our embryo is the pulsating that starts in a twist of blood vessel that is to become our heart, and the last motion of our natural body is our heartbeat. It is there for all of our natural life. And of course there is a beating heart in our spiritual bodies when we come to put them on.

399, 1. Love, or volition, is our essential life. This follows from the responsive relationship between the heart and our volition discussed in 378-381 above; for our volition acts in our mind the same way our heart acts in our body. Further, just as everything in the body depends on the heart for its origin and for its motion, everything in the mind depends on volition for its origin and its life. By "volition" I mean "love," since volition is the vessel of love and love is the essence of life (see 1-3 above). The love that is the essence of life, further, comes from the Lord alone.

By looking at the heart and its extension in the body through arteries and veins, we can learn that love or volition is our life. This is because things that correspond to each other act in the same way, the only difference being that one is physical and the other spiritual.

The science of anatomy shows us how the heart acts in the body. It shows us, for example, that everything is alive or responsive to life where the heart is at work through the channels it extends from itself, and that everything is not alive where the heart is not at work through its channels. It shows further that the heart is both the first and last thing that acts in the body. We can tell that it is first by looking at embryos, and that it is last by looking at the dying. We can tell that it acts separately from the lungs by looking at people who have suffocated or fainted. This enables us to see that the life of the mind depends entirely on volition just the way the life that supports the body depends entirely on the heart and that our volition remains alive even when thought ceases, just the way the heart does when breathing ceases. This too we can see in embryos, in the dying, and in people who have suffocated or fainted.

It follows from all this that love or volition is our very life.