Keir Martland
I’ve been sorting through my AS Philosophy file and this short essay, with which I was most pleased, fell out onto the floor. This is from when we revisited the ‘Theories of Perception’. You may recall that I once suggested that there were elements of truth to both direct and indirect realism. This essay may come as a bit of a surprise.
While objects exist, there can be no question their being independent of our minds. Objects are collections of sense experiences and as such are completely mind-dependent. It necessarily follows that, as the immediate objects of perception are mind-dependent, any talk of an external world independent of our minds and beyond our perception is meaningless.
One of the two realist theories of perception is direct realism. According to this view, there are mind-independent physical objects. These objects are the immediate objects of our perception and we perceive them directly and with no intermediary. We perceive these objects exactly as they are and every perceiver perceives these objects in the same way.
Yet, direct realism provides us with no reason to accept that there are mind-independent physical objects. A direct realist might say that we are aware of these objects, but this begs the question. In other words, in order to prove the existence of mind-independent physical objects, the direct realist points to ‘mind-independent physical objects’, presupposing their existence. This will not do, especially if one were to adopt the Cartesian method of hyperbolic doubt. Adopting this method, one might concede that one is aware of something, but this something does not have to be a mind-independent physical object. At the very most, all we can do is infer the existence of mind-independent physical objects, as the indirect realist would have us do.
Indirect realists claim that we have a perceptual awareness of mind-independent physical objects, but that this is an indirect awareness. There is an intermediary between the perceiver and the thing perceived which the indirect realist calls ‘sense data’.
All we are ever aware of, according to the indirect realist, are sense data: we see a tree because of sense data; we feel heat because of sense data; we hear music because of sense data. Yet, if this were the case and if there existed a mind-independent external world, then we would never know how accurate our perception was as a representation of that external world. This is because if all we are ever aware of are sense data, and if sense data are not the same as mind-independent physical objects, then two things follow directly: first, we can never perceive the ‘real’ world directly; second, we cannot perceive both our sense data and this real world simultaneously. As a consequence, we cannot compare our perception with the external or ‘real’ world to see how accurate it is. Thus we must accept, if we are indirect realists, that we can neither know how accurate our perception is nor what the ‘real’ world is actually like.
There exists an even more fundamental problem with the indirect realist’s theory. The existence of mind-independent physical objects is still not evidenced. Cartesian hyperbolic doubt is still applicable here. Might it not be the case that sense data is put into our minds by the Evil Demon to trick us? Indeed, the indirect realist has even less ‘evidence’ at his disposal than the direct realist. For the direct realist, our perception is the ‘proof’; we perceive a tree because there is a real, mind-independent tree in front of us. For the indirect realist, however, we only directly perceive sense data, which are caused by and supposedly represent some mind-independent physical object which does not necessarily resemble the sense data and which we can never directly perceive.
Thus it is actually the case that the indirect realist has built up a completely non-falsifiable theory for which there is no evidence. This seems as good a reason as any to reject indirect realism as a possible proof of the existence of mind-independent physical objects.
What remains (excluding the more modern theory called ‘phenomenalism’) is idealism. Idealism is an anti-realist theory of perception. Idealists, therefore do not maintain that there exist mind-independent physical objects. Rather, for the idealist, there are objects, but these are collections of sense experiences which we also call ideas. Idealists do not infer the existence of matter like the indirect realists and nor do they assert its existence like the direct realists.
For Berkeley, the founder of idealism, “esse ist percipi”: to be is to be perceived. That is to say that existence is dependent upon being perceived. Since there is no way in which we can perceive a mind-independent physical object in the way we can perceive colours, shapes, and sizes, mind-independent physical objects are not objects of our perception. Since to be is to be perceived, it follows, therefore, that mind-independent physical objects do not, in fact, exist.
Moreover, in the Master Argument, Berkeley demonstrates that mind-independent physical objects not only don’t exist, but cannot exist. Berkeley asks us to imagine an object independent of any mind. However, the object you have just imagined is not independent of any mind since it is dependent upon your mind. This way, a mind-independent object is not an object at all, since no one is perceiving it.
A mind-independent physical object is no object at all, since to be is to be perceived. Not only is the idea of a mind-independent physical object problematic, but there is also no evidence for the existence of such objects. Neither pointing at an object and labelling it a mind-independent physical object nor inferring the existence of such objects from sense data are strong enough to counter the Master Argument, which is self-evidently true and whose truth can be discovered without empirical testing.
