Final answer:
Native Americans used a fire in the middle of their house for warmth, cooking, tool making, and social gatherings. Fire was an essential part of their daily life and survival, particularly in cold climates.
Step-by-step explanation:
Based upon the account of Thomas Morton, Native Americans used a fire in the middle of their house primarily for warmth. The controlled use of fire was essential for several reasons: staying warm in cold climates, cooking meat to make it easier to consume and digest, and providing light. Fireplaces were also used in the construction of tools, where wooden spears could be hardened, and in the treatment of stone for tool making. Furthermore, fire played a crucial social function by providing a gathering spot for bonding and social connections necessary for group survival and cooperative activities. Moreover, considering the example of Jomon culture, indoor fire pits were common in their houses not only for cooking but also for warmth.