There is no single answer to this question as the definition of a scientist has evolved over time. Some historians believe that the first scientists were the ancient Greek philosophers, such as Thales of Miletus and Aristotle, who developed theories about the natural world based on observation and reason. Others argue that the first scientists were the Chinese alchemists, who experimented with chemical reactions and developed new technologies. Still, others believe that the first scientists were the Renaissance scholars, such as Leonardo da Vinci and Nicolaus Copernicus, who used experimentation and observation to develop new theories about the natural world. Ultimately, the definition of a scientist is subjective, and there is no clear consensus on who should be considered the first scientist.