Final answer:
The historical context suggests that hiring another architect to fulfill the duties of a contract was possible, as illustrated by the ascendance of Sinan to the role of chief architect after endorsement from Lutfi Pasha, despite originally having been a Janissary.
Step-by-step explanation:
The question 'May the owner hire another architect to fulfill the duties of the contract?' implies a scenario in which the original contract may need to be altered or substituted by a different arrangement.
This could relate to historical contracts or obligations concerning roles such as an architect, especially in cases where a notable architect, like Sinan during the Ottoman Empire, was assigned to a prestigious position. Historical accounts reveal that Sinan started his career as a Janissary and transitioned to architecture, indicating that vocational shifts were indeed possible, potentially due to personal choices or external influences like recommendations from a Pasha.
In the context of the excerpt provided, Lutfi Pasha's endorsement reveals that despite the existence of an agreement or understanding related to the role of chief architect, there was room for a new appointment. Thus, when a position such as chief architect fell vacant, it was indeed permissible for another architect to be hired or for someone like Sinan to fulfill the contract's duties.