This paper suggests that much of the empirical basis for the argument/adjunct distinction (A/AD) is weaker than traditionally believed. First, I argue that successful argumenthood diagnostics should both (i) identify a distinction among dependents which resembles the conventional A/AD, and (ii) draw a distinction which is not already predicted independently of the A/AD. Focusing on PPs within the VP in English, I argue that purported diagnostics for argumenthood, including omission, 'do so'-substitution, and iteration, do not meet these criteria, therefore do not provide empirical support for the A/AD. After briefly discussing the prospects for several further diagnostics, I conclude that it is plausible that the A/AD might be eliminable. Though this would raise technical questions in various areas, it would be desirable from a Minimalist perspective.