Analysis:

This quatrain by Saadi Shirazi delves into the complexities of human nature, exploring the conflict between reason and desire.

The Conflict Between Reason and Desire: The speaker acknowledges the importance of reason and wisdom but admits that they are often overpowered by their desires.
The Power of Nature: The speaker suggests that their desires are innate, a part of their very nature. This hints at a belief in the power of instinct and passion.
A Question of Creation: The speaker questions whether their desires are a fault or a natural part of their being, suggesting a philosophical inquiry into the nature of human existence.

Themes:

Human Nature: The quatrain explores the complexities of human nature, particularly the conflict between reason and desire.
Free Will: The speaker seems to be questioning the extent to which humans have free will, suggesting that their actions are often determined by their nature.
The Divine: The speaker refers to God, suggesting a belief in a higher power and questioning the purpose of human desires.

Deeper Meaning:

This quatrain can be interpreted as a meditation on the human condition. The speaker's struggle with desire reflects the universal experience of conflicting desires and the difficulty of always acting rationally. The question of whether their desires are a fault or a gift raises profound philosophical questions about the nature of good and evil, free will, and the divine.

This quatrain is a powerful exploration of the human psyche, suggesting that the complexities of human nature often defy simple explanations.