Navigation is of fundamental importance to humans, just as it is for other species. And, like most other animal species, we possess a number of distinct navigational processes. This thesis examines navigation, focusing particularly on the widely studied phenomenon of reorientation following disruption to spatial behavior. In typical reorientation experiments, subjects rely on the three-dimensional surface layout of an environment to find a desired goal following disorientation, and they do so to the exclusion of other important spatial cues. An influential explanatory framework aims to account for such findings by holding that subjects possess a modular mechanism known as the geometric module, which only operates on geometric information about three-dimensional extended surfaces. This thesis provides a sustained defense of this framework and develops a new type of geometric-module theory of reorientation. I begin by making the case that, if the general geometric-module framework is right, it has deep implications for two foundational debates in philosophy of psychology: the debate about the nature of mental representations and the debate about the structure of the mind. I then address the two most pressing challenges against the framework. The first challenge comes from what I call ‘the explanatory inflexibility objection’, which holds that the geometric-module framework simply does not have the required flexibility to deal with evidence that non-geometric cues can affect subjects’ search behavior in some experimental contexts. The second challenge arises from an alternative explanatory framework, the view-matching framework, which aims to explain subjects’ behavior in reorientation experiments by appealing to snapshots, stored representations of the subjects’ two-dimensional retinal stimulation at specific locations. In answering these two challenges, I put forward a new type of geometric-module theory which has stronger implications for debates in philosophy of psychology than standard geometric-module models
