Different kinds of conditionals:Coin tosses and kangaroos in the forest of alternative possibilities

我们的项目将提供一种新的、统一的条件句分析（“如果a那么C”），它承认不同类型条件句的细粒度区别，采用一种可以表示不同类型可能性的形式框架。该项目汇集了迄今为止互不相关的见解，这些见解来自于对各种可能性的形式和形而上学方面的哲学研究，以及对条件句组成结构中情态和时态相互作用的语言学研究。我们将建立在哲学洞察力的基础上，即时间和模态的替代可能性（“硬币可能正面落地”vs.正面落地）。“袋鼠可能没有尾巴”)需要不同的形式处理，因为它们与现实的关系不同：树状有序分支结构充分代表了我们世界中的时间选择，而模态选择则通过不同的可能世界得到最好的表现。我们建议将这些结构结合起来进行统一分析，这将基于（暂时树状有序）替代可能性的（模态）森林。我们将用语言学的见解来补充这些哲学和形式的见解，特别是关于言语时态在决定所考虑的条件中哪种可能性处于危险中的作用。该项目由三个子项目组成，将研究(1)通过时态的使用反映的条件句中时间和认知可能性的动态，(2)基于情态替代可能性的条件句，突出过去时在这些情况下的作用，以及(3)条件句的因果依赖性和独立性的作用，特别是涉及诸如抛硬币之类的不确定性事件。我们项目的主要方法论方面是学科和正式建模的交叉施肥。我们的目的是表明，成功地整合语言学和哲学的当前研究可以导致对条件句的不同现象的统一看法。

Our project will provide a novel, unified analysis of conditional sentences ("if A then C") that acknowledges a fine-grained distinction of different kinds of conditionals, employing a formal framework that can represent different kinds of possibilities. The project brings together insights, so far unconnected, from the philosophical study of the formal and metaphysical aspects of varieties of possibilities and from the linguistic study of the interaction of modals and tenses in the compositional structure of conditional sentences. We will build on the philosophical insight that temporal and modal alternative possibilities ("The coin could have landed heads" vs. "Kangaroos could have no tails") require different formal treatments due to their different relation to actuality: tree-like ordered branching structures adequately represent temporal alternatives in our world, while modal alternatives are best represented via distinct possible worlds. We propose to combine these structures for our unified analysis, which will be based on a (modal) forest of (temporally tree-like ordered) alternative possibilities. We will complement these philosophical and formal insights with insights from linguistics, esp. concerning the role that verbal tense plays in determining which kind of possibility is at stake in a conditional under consideration.The project consists of three sub-projects that shall study (1) the dynamics of temporal and epistemic possibilities in conditionals as reflected by the use of tense, (2) conditionals based on modal alternative possibilities, highlighting the role of the past tense in these cases, and (3) the role of causal dependence and independence for conditionals, esp. concerning indeterministic events such as coin-tosses. The main methodological aspects of our project are the cross-fertilization of disciplines and formal modelling. Our aim is to show that a successful integration of current research from linguistics and from philosophy can lead to a unified view of the diverse phenomenon of conditionals.