Option 1: Aristotle was a Greek philosopher and scientist, known for his work in various fields including physics, biology, and ethics. While he made significant contributions to the study of nature, he is not typically referred to as the "Greatest investigator of antiquity".

Option 2: Darwin, the correct answer, is known as the "Greatest investigator of antiquity". Charles Darwin was a British naturalist who is best known for his theories of evolution and natural selection. His groundbreaking work, "On the Origin of Species", revolutionized the understanding of the natural world.

Option 3: Cuvier, also known as Georges Cuvier, was a French naturalist and zoologist. While he made important contributions to the field of comparative anatomy and paleontology, he is not referred to as the "Greatest investigator of antiquity".

Option 4: Socrates was an ancient Greek philosopher and is widely regarded as one of the founders of Western philosophy. However, he is not known for his investigations into antiquity or scientific exploration.

Therefore, the correct answer is option 2, Darwin.