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

我们的项目将提供一个新颖的，统一的分析条件句（“如果A，那么C”），承认细粒度的不同种类的条件的区别，采用一个正式的框架，可以代表不同种类的可能性。该项目汇集了迄今为止互不相关的见解，这些见解来自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。我们将建立在这样一种哲学见解的基础上：时间和模态的替代可能性（“硬币可能是正面的”与“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替代，而模态替代最好通过不同的可能世界来表示。我们建议联合收割机这些结构，我们的统一分析，这将是基于（模态）森林（时间树状有序）替代的可能性。我们将用语言学的观点来补充这些哲学和形式上的见解，特别是关于动词时态在决定哪种可能性在所考虑的条件句中处于危险之中的作用。该项目包括三个子项目，将研究（1）时态的使用所反映的条件句中时间和认识可能性的动态，（2）基于模态选择可能性的条件句，强调过去时态在这些情况下的作用;（3）因果依赖和独立对条件句的作用，特别是关于不确定性事件，如抛硬币。我们的项目的主要方法方面是学科和正式建模的交叉施肥。我们的目的是表明，一个成功的整合目前的研究从语言学和哲学可以导致一个统一的看法的不同现象的条件句。

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.