In this reply we address comments by Cloninger (this issue) related to our report (Farmer & Goldberg, this issue) on the psychometric properties of the revised Temperament and Character Inventory (TCI-R) and a short inventory derivative, the TCI-140. Even though Cloninger's psychobiological model has undergone substantial theoretical modifications, the relevance of these changes for the evaluation and use of the TCI-R remains unclear. Aspects of TCI-R assessment also appear to be theoretically and empirically incongruent with Cloninger's assertion that TCI-R personality domains are non-linear and dynamic in nature. Several other core assumptions from the psychobiological model, including this most recent iteration, are non-falsifiable, inconsistently supported, or have no apparent empirical basis. Although researchers using the TCI and TCI-R have frequently accepted the temperament/character distinction and associated theoretical ramifications, for example, we find little overall support for the differentiation of TCI-R domains into these two basic categories. The implications of these observations for TCI-R assessment are briefly discussed.