If I were to speak your kind of language, I would say that man’s only moral commandment is: Thou shalt think. But a “moral commandment” is a contradiction in terms. The moral is the chosen, not the forced; the understood, not the obeyed. The moral is the rational, and reason accepts no commandments.
My morality, the morality of reason, is contained in a single axiom: existence exists — and in a single choice: to live. The rest proceeds from these. To live, man must hold three things as the supreme and ruling values of his life: Reason — Purpose — Self-esteem. Reason, as his only tool of knowledge — Purpose, as his choice of the happiness which that tool must proceed to achieve — Self-esteem, as his inviolate certainty that his mind is competent to think and his person is worthy of happiness, which means: is worthy of living. These three values imply and require all of man’s virtues, and all his virtues pertain to the relation of existence and consciousness: rationality, independence, integrity, honesty, justice, productiveness, pride.