Why does a man need to pacify his mind and heart? The Orient has the Tai Chi symbol of Yin and Yang, which many assume is an exhortation towards balance, or harmony. Many in the West have also adopted this balance to life perspective, expending energy into quelling the storms of their life. True Tai Chi form functions when, and only when, the tension of Yin and Yang are intensified to produce intended effect. The Yin, or the heaviness, is pushed towards the earth, while the Yang, or the lightness, is floated towards the heavens. Life occurs in controlled tension between Yin and Yang, water and fire. When life attains balance and passivity, it usually indicates death.
Man is capable of great good, kindness, and wisdom. The long list of saints from Benedict to Pius X indicate the ability of men to rise beyond their beastly natures. Yet, man is also a creature with tendency towards infinite evil. The longer list of worldly tyrants to petty criminals accuse humanity of their beastly nature. Both these realities are principles of humanity. Can a man truly claim to understand his fellow man, while ignoring one-half of man's nature? Even the great atheist Nietzsche wrote that man is a rope stretched between the animal and the uebermensch.
The commandments are universal, everyone understands them. Don't kill, don't hurt others, don't steal, don't lie, etc. These principles would not be needed if we lived in a world where they are respected.
If these commandments are, as you postulate, universal, then by what compulsion would our creator seek to encode it in stone? It would be as farcical as giving instructions on sleeping, eating, and mating. Instructions and commandments are provided because such concepts are foreign to those, to whom such instructions are given.
The compulsion of God, to love thy neighbor as yourself, is precisely difficult because despite the beastly nature of humanity, we must extend curtesy and friendship to our fellow man and to ourselves. We must envision our own sainthood, despite our beastly nature. But all this only within the sphere of influence my station allows; human history is filled with hubris of men, reaching beyond their station, to deliver heaven upon their unsuspecting neighbors and creating hell.
Peace of Christ be with you and your family.