We can tell what the shape or size of an object is by either sight or touch. These two senses are very different in character, not only in the mechanisms of perception – the physical media, the physiological organs of sense and possibly the psychological processing involved – but also in their phenomenological character, what it is like to see and to feel.

This can lead one to ask how it is that the same properties can be perceived by the two senses, and the issues that surround this question have been discussed by both philosophers and psychologists over the centuries. But a converse question also arises, namely, given that the same properties are perceived, where does the difference between the senses lie? Is this phenomenological difference really a difference in spatial perception between the senses? That is the topic of this paper.

The commonest treatment of these issues fails to offer any satisfactory answer. It suggests that we can look for one in two places: in the different properties of things in the world that are perceptible by each of the senses; or in the different subjective qualities of perceptual experiences. Since we are concerned with the differences between senses with respect to perceiving the same properties, the former approach is not applicable. But the latter approach fails to offer any illuminating answer to the question. For it simply posits some introspectible difference between the senses without saying any more about it.