For almost a century, the somatic mutation theory (SMT) has been the prevalent theory to explain carcinogenesis. The SMT posits that the accumulation of mutations in the genome of a single normal cell is responsible for the transformation of such cell into a neoplasm. Implicitly, this theory claims that the default state of cells in metazoan is quiescence and that cancer is a cell-based, genetic and molecular disease. From lessons learned while performing our own research on control of cell proliferation and while adopting an organicist perspective, in 1999, we proposed a competing theory, the tissue organization field theory (TOFT). In contraposition to the SMT, (1) the TOFT posits that cancer is a tissue-based disease whereby carcinogens (directly) and mutations in the germ-line (indirectly) may alter normal interactions between the stroma and their adjacent epithelium. And (2) the TOFT explicitly acknowledges that the default state of all cells is proliferation and motility, a premise that is relevant to and compatible with evolutionary theory. Theoretical arguments and experimental evidence are presented to compare the merits of the original SMT and its variants and those of the TOFT in organizing principles, construct objectivity, and ultimately explain carcinogenesis.