Final answer:
The Urim and Thummim stones in 'The Alchemist' are symbolic tools for Santiago's personal growth, representing his initial dependency on divine guidance which he gradually outgrows as he learns to follow his intuition.
Step-by-step explanation:
The introduction of the stones, Urim and Thummim, in the novel The Alchemist by Paulo Coelho, serves as an important plot device for the character development of Santiago.
These stones symbolize elements of divination and decision-making and represent Santiago's reliance on supernatural guidance on his journey. With time, as Santiago grows and learns to listen to his heart and interpret the omens of the physical world around him, he becomes less dependent on the stones.
Hence, they are also a tool that reflects Santiago's personal growth, from depending on clear-cut signs to developing his intuition and understanding that not all answers are black and white, which is part of his maturation process and quest for his Personal Legend.