A Theory of Sentience is as valuable for the questions it opens up as for the positive theory it puts forward. Austen Clark has brought to our attention a way of thinking about the details of sensory experience which opens up possibilities for fruitful interaction between philosophy, pscychophysics and the neurosciences. It is refreshing to read an exploration of sensory experience which fixes the terrain of investigation firmly within the actual world and which works hard to define tractable problems based around the basic, but often neglected, truth that sensory experience is sensory experience of a three-dimensional environment.