Munich Center for Mathematical Philosophy (MCMP)

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Zoom Talk: Haixin Dang (Leeds)

Meeting-ID: 962 2792 6351

01.07.2020 16:00  – 18:00 

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Collective Justification, Group Reasons, and Disagreement in Science


We often gain knowledge from the testimony of groups, especially scientific groups. For example, the Intergovernmental Panel on Climate Change tells us: “global climate change is caused by human activity.” How is the group justified in making this claim? In this talk, I will focus on one aspect of the problem of collective justification: Group G collectively claims that P. In support of P, the group G also holds two different reasons for P: Q and R. In order for the group to be collectively justified in claiming that P, must all members of the group also be in consensus on the reasons Q and R, in addition to P? This talk explores the relationship between group beliefs/claims and group’s reasons for those beliefs/claims. I am primarily interested in the distribution of reasons within a group or what it means for a group to provide reasons, not the state of justification or what it means to be justified. I survey the different ways in which the group and its members may substantiate different “structures” of collective justification. In ideal cases, for collective justification, we expect consistent attitudes towards the conclusion and the reasons for the conclusion, so there is agreement across members of a group around the reasons for P and P itself. I argue that this is a far too limited a view of how collective justification may arise in a group. For example, members of the group may be in some disagreement over the reasons for P, but there may be in consensus on P itself. In this case, I argue that the group is nonetheless collectively justified in the conclusion. I also explore other possibilities, such as when members of a group are in agreement on the reasons for a conclusion, but disagreement over the conclusion itself. While this case may not result in collective justification, we can still learn a lot about a group in various states of disagreement. Different justificatory structures obtain in real groups all the time. In conclusion, I argue that we must widen our understanding of collective justification to better reflective real social epistemic processes.