Threshold concepts are a widely used idea, particularly in curriculum design and evaluation of student learning. However they can be criticised as being hard to identify, vague and teacher imposed. Using the cognitive theory of Bernard Lonergan we argue that his epistemology enables us to reframe threshold concepts by adding a learner focussed understanding. We extend this to include considerations of liminality and 'stuckness', as well as the multiple paths to the threshold learners may take. Adding an understanding of cognitive process to the idea of threshold concepts also enables us to understand how they can be identified in disparate subjects.