Early Vedic possesses a chameleon-like verb form called the injunctive, whose uses partly overlap with, and alternate with, those of the subjunctive, optative and imperative moods, and with the past and present tenses. Being morphologically tenseless and moodless, the injunctive has attracted interest from a comparative Indo-European perspective because it appears to be an archaic layer of the finite verb morphology. Its place and function in the verb system, however, remains disputed. In Kiparsky 1968 I argued that it is tenseless (...) and moodless not only morphologically but also functionally, and that injunctive forms acquire modal and temporal interpretations only contextually. The injunctive’s only intrinsic grammatical features are aspect, voice and person/number. This paper provides new evidence for that view (section 1), and goes on to argue that such underspecified forms in paradigms support morpheme-based theories of morphology over realizational theories such as Paradigm Function Morphology (section 2), and that the rise and loss of the injunctive is connected to other changes in the pre- and post-Vedic aspect, tense, and mood system (section 3). (shrink)