Abstract Tocharian possesses a highly complex verbal system and has played a major role in theories about the PIE verb in recent decades. While it is certainly true that Tocharian deserves the highest attention for theories about the protolanguage, not every trait of its verbal system has to be explained by direct top-down developments and not every trait can be directly transferred onto the proto-language. The paper discusses the Tocharian causative stems and argues that an inner-Tocharian development for the system of causatives is more likely than deriving the various stems from respective PIE stems directly.

中文翻译：

---

吐火罗因果系统的发展——自上而下还是自下而上？

摘要 Tocharian拥有高度复杂的语言系统，近几十年来在PIE动词的理论中发挥了重要作用。虽然吐火罗语的原始语言理论确实值得最高关注，但并非其语言系统的每个特征都必须通过直接自上而下的发展来解释，也不是每个特征都可以直接转移到原始语言上。这篇论文讨论了吐火罗因的因果词干，并认为比起直接从各自的 PIE 词干推导出各种词干，因果系统的内部吐火罗发展更有可能。