In their papers prepared for this volume, Kelly DeVries and David Zimmerman explore the differing viewpoints on technological determinism that military historians bring to bear on premodern and modern warfare. This paper analyzes their respective arguments, including DeVries's introduction of the concepts of effectiveness, invincibility, and decisiveness; it focuses primarily on technological determinism. It explores some concepts of historical causation and concludes that nothing in human behavior is deterministic. It recommends language that can help historians avoid this rhetorical battleground and speak more clearly and judiciously about the factors that shape warfare and affect its outcome.