Who was one of the earliest figures known to experiment on animals?

Aristotle is recognized as one of the earliest figures to experiment on animals, particularly in his studies of biology and physiology. He is known for his systematic observations of animals, which laid the groundwork for the biological sciences. Aristotle's approach included dissection and observation, providing foundational knowledge about animal anatomy and behavior. His work established a tradition of empirical study in the natural sciences, influencing future generations of scientists and philosophers regarding the use of animals in research.

In contrast, figures such as Louis Pasteur and Claude Bernard made significant contributions to microbiology and physiology later in history, while Peter Singer is primarily known for his work in animal rights and ethics, rather than early experimentation.