Who is credited with proposing that new cells arise only from previously existing cells?

The idea that new cells arise only from previously existing cells is a fundamental principle of cell theory, which was significantly advanced by Rudolf Virchow. He formulated the statement "Omnis cellula e cellula," meaning that every cell originates from another cell. This concept helped to establish the understanding that cellular reproduction is a process that maintains the continuity of life through the replication of existing cells. Virchow's work built upon earlier findings in cell biology and contributed to our understanding of biological processes such as growth, tissue repair, and reproduction.

Other figures mentioned, although important in their own right, did not specifically propose this key idea. Louis Pasteur is known for his work in microbiology and fermentation, while Robert Hooke is credited with discovering and naming cells through his observations of cork. Gregor Mendel is recognized as the father of genetics for his work on inheritance patterns in pea plants. Each of these scientists made significant contributions to their respective fields but did not directly propose the principle of cell division as Virchow did.