Sentences that are ungrammatical and yet intelligible are instances of what I call perfectly thinkable thoughts. I argue that the existence of perfectly thinkable thoughts is revealing in regard to the question of why syntactic islands should exist. If language is an instrument of thought as understood in the biolinguistics tradition, then a uniquely human subset of thoughts is generated in narrow syntax, which suggests that island constraints cannot be rooted in narrow syntax alone and thus must reflect interface conditions imposed on the output of the computational system and its mapping to external systems.

中文翻译：

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为什么要存在句法孤岛？

不合语法但可以理解的句子是我所谓的完全可以思考的想法的实例。我认为，完全可思考的思想的存在揭示了为什么句法孤岛应该存在的问题。如果按照生物语言学传统的理解，语言是一种思维工具，那么在狭义句法中会产生独特的人类思维子集，这表明孤岛约束不能仅植根于狭义句法，因此必须反映强加于语言输出的界面条件。计算系统及其到外部系统的映射。