Claim. Because all beings have dual Sungsang and Hyungsang aspects, ethical law (a Sungsang law) and natural law (a Hyungsang law) stand in a relationship of correspondence — making it possible to ground ethical norms in scientifically discovered features of nature, provided nature is correctly understood.
Elaboration. Lee argues that modern people accept ethical claims only when they are supported by natural-scientific reasoning (B. Philosophical Ground for the New View of Absolute Value). He cites historical precedent: ancient Greek and Oriental thinkers (notably Chu Hsi, who asserted that natural law becomes the ethical law of human society) read ethics off nature; even Marxism, despite its faulty natural-law concept, claimed identity between natural and social law (both developing dialectically).
The UT version of the move: ethical law is Sungsang law, natural law is Hyungsang law, and since Sungsang and Hyungsang are always united in beings, the two laws correspond. This is a strong realist claim — ethics is not free-floating, it is the inner-aspect counterpart of physical law, and both come from the same Creator-Logos.
The critical caveat: “how we can obtain a correct understanding of nature” is decisive. Marxist dialectics started from an inaccurate reading of nature (positing fundamental struggle between opposites) and therefore derived an incorrect way of life (class struggle). The corrective: UT holds that the fundamental law of the universe is the law of give-and-receive action with its seven characteristics — correlativity, purposiveness and centrality, order and position, harmony, individuality and relatedness, identity-maintaining and developmental nature, and circular motion. From these characteristics Lee derives vertical, horizontal, and individual values.
This is UT’s philosophical reply to the is/ought problem. Hume and the analytic tradition treat the gap between fact and value as unbridgeable; Lee bridges it ontologically by making fact (Hyungsang) and value (Sungsang) two aspects of the same beings. Critics in the analytic tradition would push back hard — they would argue this either smuggles values into the description of nature (the seven characteristics already encode normative concepts like ‘harmony’ and ‘purpose’) or commits a naturalistic fallacy. The UT response is that the smuggling charge presupposes a value-free nature, which UT denies on theological grounds.
See also. sexual-order-as-core-of-ethics, family-as-microcosm-of-the-way-of-heaven, logos-unites-freedom-and-necessity