Claim. Heart (Shimjung) is the core of God’s Sungsang — defined as ‘the emotional impulse to seek joy through love’ — and is the most important aspect of the Divine Character, never before clearly taught in any other school of thought.
Elaboration. Lee positions Heart as UT’s most distinctive theological contribution. Other religions affirm omniscience, omnipotence, love, supreme good; UT also affirms these as part of the Divine Character but treats Heart as more fundamental — the core of God’s interior life from which the rest derives (1. Heart).
The definition has three structural elements: (1) it is an ‘emotional impulse,’ (2) directed toward joy, (3) but joy can only be obtained through love. Lee explains the impulse character: emotional impulses, unlike ordinary desires, cannot be repressed by will. Everyone seeks joy by their very nature; criminals commit crimes pursuing joy in the wrong direction. The impulse to seek joy cannot be suppressed.
But humans rarely attain true joy because they pursue it through money, power, knowledge — means that cannot deliver. Joy comes only through love: ‘an altruistic life of service, a life lived for the sake of others, a life lived by pleasing others with a warm heart.’ The metaphysical basis is that the foundation of joy lies in God, and in God the impulse to seek joy is grounded in the impulse to seek love, since true joy can only be obtained through love. Therefore ‘the impulse to seek love is stronger than the impulse to seek joy’ — love is primary, joy is the necessary result.
Love necessarily requires an object partner, and God’s love is an irrepressible impulse, so an object partner was ‘absolutely necessary for God.’ This makes creation ‘necessary, inevitable, and can never be considered as merely accidental.’ This is the Heart Motivation Theory — creation flows from God’s interior impulse, not from divine freedom in any libertarian sense. Critics from classical theism engage on whether this compromises divine aseity (does God need creation?). Worth a thread once a classical-theism counter-atomic exists.
See also. creation-was-necessary-not-accidental, god-is-the-god-of-heart, concept-of-heart-emotional-impulse-seeking-joy-through-love