What was A.E. Housman’s objection to treating one manuscript as automatically authoritative?

A.E. Housman strongly objected to the practice of designating a single "best manuscript" (codex optimus) as automatically authoritative based on rigid, "scientific" stemmatic grounds.1

His critique, famously articulated in his prefaces to editions of Manilius and Juvenal, targeted the misuse of the genealogical method, which often led editors to defend readings as authentic even when they were clearly erroneous. Housman argued that such an approach ignored the necessity of common sense and the use of reason in textual criticism. He maintained that no mechanical application of a method could replace the critic's judgment, emphasizing that a critic must be able to discriminate between readings on their intrinsic merits rather than relying blindly on the perceived authority of a single source. Ultimately, Housman believed that if the results of a method conflict with common sense, the method is being applied illogically.12