Imagination

2. Imagining and perceiving

Paradigmatic cases of imagining seem to be akin to the act of seeing something. Aristotle (On the Soul; On Dreams: c.360s bc–320s bc ) was sufficiently struck by the similarities between imagining and perceiving to claim that both were movements within the single faculty of sense perception.

One similarity that has drawn the attention of philosophers is that of perspective. Paradigmatically, we adopt a particular perspective when we imagine things. Just as it is difficult to see the front and back of a house at the same time, it is difficult to imagine the front and back of a house at the same time. This has been an important datum in discussions of imagination. It has been used in favour of the reification of mental images with pictorial properties, whereby the need for perspective in imagination can be likened to the need for perspective in a painting. And it has been used against the view that paradigmatic cases of imagining can be thought of as the mere entertaining of a set of propositions, for the reason that the entertaining of a set of propositions seems no more restricted to a single perspective than a set of architectural descriptions in a book.

While obviously similar, there are, equally obviously, differences between paradigmatic cases of imagining something and perception. The most obvious difference is external to the agent: when one perceives a thing, that thing will tend to figure in the explanation of the perceiving, but when one imagines a thing, it will typically be inappropriate to invoke that thing in an explanation of the imagining. But there are also differences of a phenomenological kind between imaginings and perceivings, differences that can be sensed from the first person point of view. One difference that has often been highlighted – by Aristotle (On The Soul; On Dreams), Sartre (1948) and Wittgenstein (1953), for example – is this: imaginings seem subject to the will, perceivings not. This point can be pushed too far. For there do seem to be cases where one’s imagination runs riot (to the extent that one’s imaginings may be involuntary), and yet there is something quite right about the idea that I can ask you to imagine something in a way that I cannot ask you to perceive or believe something. Other differences between imaginings and perception have been explored. A common idea is that imaginings involve the entertaining of thoughts that are neither affirmed or denied, whereas both perceiving and believing involve taking something as true. Sartre offers a rather different account. When one perceives x, he explains, the presence of x is posited by the perception. When one imagines x, not only is the presence not posited, but its absence is posited. For Sartre this contrast is an important clue to the nature of consciousness: the presence posited by perception is used to account for our sense of ‘being-in-the-world’, the posited absence by imagination being the fundamental exercise of freedom, whereby one withdraws from the world.