What are we aware of when we look at an ordinary object, like a tomato? Naïvely, we might answer: the tomato itself. In perception, mind-independent objects are present to our minds. Yet, as Godfrey Vesey crisply explains in introducing the present programme, philosophers have long thought that this naïve view is inconsistent with two very general empirical facts.
The first fact is that brain activity of the very same kind that accompanies seeing a tomato might occur in the absence of any tomatoes. If it did so, it would give rise to an experience which, from the inside, we could not tell apart from genuinely seeing a tomato: an hallucination. The second fact is that it takes time (in the case of stars, many years) for light from objects to reach our eyes. In this time, the object seen might cease to exist without affecting our experience. Yet how can a non-existent object be present to our mind?
Rodney Hirst takes these facts to show that the objects of awareness are never out in the world. Instead, what is before the mind when we see or hallucinate are internal mental objects (aka: representations, images, ideas, or sense-data). These objects may resemble and so represent things like tomatoes. Directly seeing (or being aware of) such objects helps explain how we indirectly see the mind-independent world.
Alan White is quite unimpressed with Hirst’s theory. (This despite the fact that he wrote his doctorate on G. E. Moore under the supervision of A. J. Ayer – both notable, albeit very different, sense-datum theorists.) He presses several crucial questions. What does the direct/indirect contrast actually amount to? How does the theory apply to other senses than vision? Why think there is any object present to the mind in cases of hallucination?
These are excellent questions. However, it is natural to feel frustrated at White’s reluctance to offer a positive account of perception. Ordinary language philosopher that he is, White sees his task as explaining why people speak as if they see things in hallucinations. But given that White denies that there is any object before the mind in hallucination, what we really want to know is why it seems to the subject as if there is, and what if anything follows about cases of genuine seeing. Hirst’s representative account provides clear answers here: in all cases of experience a mental object is before the mind. White does admit that in both seeing and hallucinating a tomato we have “very similar” experiences. But we are not told what the nature of either is.
The time lag argument has largely faded from contemporary debates. But the problem of hallucination remains the central issue for philosophers of perception today. However, were Vesey to host a similar debate in 2021, it would involve a rather different opposition.
In one armchair, would likely be a defender of intentionalism. Like Hirst, the intentionalist thinks of perceptual experiences as representing the mind-independent world. However, intentionalism dispenses with mental images or sense-data. Instead, intentionalism resists idea that the states of mind involved in either seeing or hallucinating involve any object strictly being present to the mind. Instead, such states “directly” represent mind-independent objects, something they can do whether or not any such object exists. (A hint of such a view can be found in White’s remark that suspecting foul play, does not require any actual foul play.)
In the other armchair, would likely be a defender of naïve realism, the view that visual awareness really does involve mind-independent objects like tomatoes being present to our minds. Our naïve realist would respond to the problem of hallucination by claiming that genuine perceptions and hallucinations are states of fundamentally different kinds—a view known as disjunctivism. This disjunctivist manoeuvre provides a way to reconcile Hirst’s thought that objects can literally be present to the mind in genuine cases of seeing with White’s resistance to the idea that any object is present to the mind in cases of hallucination. The sophisticated development of this disjunctivist naïve realist position is arguably the most important development in traditional philosophy of perception in the fifty years since White and Hirst’s debate.
Ian Phillips is a Bloomberg Distinguished Professor of Philosophy and Brain Sciences at Johns Hopkins University, jointly appointed in the William H. Miller, III Department of Philosophy, and the Department of Psychological and Brain Sciences.
Related videos and essays (all links open in a new window):
- Other Minds: A. J. Ayer and Godfrey Vesey discuss the problem of other minds.
Accompanying essay by Anita Avramides.
- Mind and Brain: Charles Taylor and Anthony Quinton discuss the mind-body problem.
Accompanying essay by Tim Crane.
- Free Will: Geoffrey Warnock and psychologist B. F. Skinner discuss free will and determinism.
Accompanying essay by Daniel C. Dennett.
- The Concept of Mind: Gilbert Ryle and Susan Haack discuss Ryle’s work on the mind.
Accompanying essay by Susan Haack.
- Time: Bernard Williams and physicist Dennis Sciama discuss time from the perspectives of philosophy and physics.
Accompanying essay by Craig Bourne and Emily Caddick Bourne.
Accompanying video with Anna Alexandrova, Huw Price and Astronomer Royal, Lord Martin Rees.