welcome covers

Your complimentary articles

You’ve read one of your four complimentary articles for this month.

You can read four articles free per month. To have complete access to the thousands of philosophy articles on this site, please


What’s Out There?

Edward Ingram visits Roboworld.

There was once a mad scientist who built robots. These robots were as clever as human beings. They could play cricket, do sums, drive cars, wash dishes; there wasn’t anything that a human could do which the robots could not. Naturally, the mad scientist equipped them with robot eyes and robot ears and other robot sense organs (for, if they could not see, hear, touch, and so on, how could they be expected to act intelligently?). And so it was that, of the thousands of the machines that were built, each was as clever and sentient an individual as you or me.

There was, however, a difference between the robots and the humans. The robots never disagreed with each other! And they could not understand why the humans were forever arguing, even over the simplest things. “Seeing is believing,” said the robots, “and that’s all there is to it. Why can’t the humans just go out and look at the evidence, and then put an end to their interminable squabbling ?”

The robots, you see, thought that everything people and robots knew was based upon the evidence of their senses – that, and cast-iron logic (and robots, of course, never had an illogical thought). Their senses, they believed, provided perfect evidence of the world. What they saw was real, and what they didn’t see and could not see (under any conceivable circumstance) was not real.

After a while the robots considered that they were so superior to human beings in this respect that they turned on their creator. They killed the mad scientist and all other human beings, and took over the planet where they had originated.

And so it was that Roboworld was born – a planet populated by robots!

As time passed the robots, being just as clever as any human being who had ever lived, became interested in the things that had interested human beings: art, history, science, music, and so on. However, what interested them most was the problem of perception. You see, just after they killed all the humans they made an appalling discovery. Their creator, being a mad scientist, had given them an imperfect (in fact, some would say perverse) set of perceptual organs. Specifically, he had arranged matters such that, when confronted with something which a human being would have considered to be one colour, the robots perceived it as being a different colour. Thus, for example, you and I experience grass as green, but one of these robots might have experienced it as our (i.e. ‘human’) red. Worse, another might have seen it as ‘human’ yellow, or orange, or purple, or blue, or who knows what! And it was not just with their eyes that the mad scientist had played this vicious trick. It was with all their senses. Thus whilst two robots might have agreed that honey tastes ‘sweet’, because each would have learned to associate the word ‘sweet’ with its experience of tasting honey, one might have tasted honey as being ‘human’ sour and the other as ‘human’ salt. And the same with touching, the same with smelling, the same with hearing: each robot experienced the world in a way totally different from that of all other robots.

(In case you’re wondering how the robots made this discovery, the confession was unearthed, in the course of robot historical research, in the mad scientist’s work notes.)

Robot reasoning then went like this:

If the world ‘out there’ is real it has real qualities. Grass really is ‘green’ if grass is real, and thus if grass is real ‘green’ is real, and if the ‘greenness’ of grass is real, robots, being superior beings, should be able both to experience green and to know that they were experiencing green.

However, as things stood, even though they agreed that the word ‘green’ should be applied to grass, none could be sure that the ‘green’ it was experiencing was the ‘right green’ to be associated with grass. For all any could tell, the ‘right green’ to go with grass would be the ‘red’ which it experienced when it looked at, say, a London bus. Moreover, even if a fortunate robot happened to experience the ‘right green’ to go with grass, it couldn’t know it was experiencing the ‘right green’.

So, if none of them could know what ‘green’ was, then even though all could admit that there was a ‘right green’, any agreement between them was superficial: after all, they were saying things were the same (e.g. “My ‘green’ is the same as your ‘green’ ”) when really they were different. Yuk!

At this point an old and clever robot stepped in. The discussion was silly, he declared, because the only thing that mattered was that all the robots agreed that grass was ‘green’, and it mattered not a hoot whether or not each experienced its ‘green’ in the same or in a different way from other robots. The important thing was for all robots to use the same words in the same way. So long as they did this, they would all know what everybody was talking about. “What really would be sick,” concluded this old and clever robot, “would be for two of us robots to agree that one thing, say grass, is green, but for the two of us to disagree on the greenness of something else, say my coat, which, I think, we can all agree is green (however any one of us actually experiences it).” (At this point the robot triumphantly, and smiling, pointed to its green suede overcoat.)

Alas for this old and clever robot, the mad scientist had allowed for just such a situation. He had jiggled robot wiring such that two robots could agree that one thing was of one colour, yet disagree upon whether another thing was the same colour. And this is just what happened: some of the robots said that the old and clever robot’s coat was, indeed, green whilst others declared, with complete sincerity, that, no, really it was blue (or, more accurately, what each of them called blue).

Things took a turn for the worse when it was discovered by a team of scientist robots that certain insects could see colours which no robot had ever experienced. “If some insects can see in the ultra-violet,” stated an embarrassed entomologist robot, “it is possible that there exist creatures that can experience red, green, blue, orange, yellow, brown, purple, black, white, and all the various shades thereof, plus some other colour. Now, it’s difficult enough imagining a new combination of existing colours. I can’t imagine something I’ve never experienced, much less a combination of things I’ve never experienced. It makes my head spin.”

Appreciate that the robots considered themselves to be perfect, superior to all other sentient beings. It now appeared as though some creatures – very unintelligent creatures to boot – had access to a reality which no robot could, in principle, experience. This was therefore a ghastly conclusion.

At this stage a young and, some would say, genius robot stepped in. This robot distinguished between things which were undeniably ‘mental’ or ‘in here’ – the colours dancing before their eyes when they viewed a field of spring flowers, the sounds between their ears when they listened to a symphony, the pleasant aromas behind their noses when they sniffed fine wine, and so on – and some things were undeniably ‘physical’, or ‘out there’ – physical things like size, shape, and weight. “Colours can’t kill you,” declared this genius young robot, “but a 1000 kilo weight dropped on your head can.”

This consideration seemed to solve the problem: there were ‘primary qualities’ – height, length, weight, shape, and so on – and ‘secondary qualities’ – colour, taste, smell, and suchlike. The primary qualities were really ‘out there’ but the secondary ones were just ‘in the head’, and as such didn’t matter; all that was important was that every robot applied the same labels to them. And as secondary qualities were just ‘in the head’, it didn’t matter that different robots, and insects for that matter, had different things ‘in their heads’, because the things ‘in their heads’ were not ‘real’, at least, not in the sense that the primary qualities were, because the primary qualities were ‘out there’ as well as ‘in here’, and being ‘out there’ was a necessary condition for something to be considered ‘real’. After all, ‘out there’ qualities could kill one (like 1000 kilo weights dropped on one’s head) but ‘in here’ qualities could not.

Now, it might be thought that there was at least one sourpuss robot who could have pointed out that attributes such as length, height, and so on, could be deciphered only through secondary qualities. As such, primary qualities should not be viewed as primary after all, for they are inferred (i.e., not experienced directly) from secondary qualities. An art historian robot, for instance, could have pointed out that artists of the school known as Impressionism, most notably Monet1, achieved their effects not through painting shapes or forms but through painting blobs of pure colour as, and only as, their eyes ‘experienced’ them. So, if one looks closely at an Impressionist painting, one sees only blobs of pure colour, but if one looks at one from a distance, shapes and forms ‘leap out’ from the canvas. However, it must be remembered that these robots were intent upon not arguing – they considered themselves superior to humans, recall – and so (an interim consensus having been achieved) no robot was prepared to rock the intellectual boat.

What spoiled things was the discovery that their mad scientist creator had played another mean trick. “Look at this,” said a perplexed robot to a friend as he exposed the following diagram:

“The horizontal line in the top figure looks longer than the horizontal line in the bottom figure,” he said. “But when I measure them it appears as though they are the same length.”

This was verified by means of experiments with hundreds of robots. And not only did all robots experience the ‘illusion’, some robots experienced more of an illusion than did others, that is, some thought the upper line was ‘much longer’ whilst others thought that it was only ‘a little longer’.

The conclusion seemed inescapable. Length was not a primary quality after all. The length something appeared to be was as much an ‘in the head thing’ as the colour that same something appeared to be. And not only was it with length that such things happened: robot psychologists subsequently determined that all so called primary qualities – weight, volume, shape, and so on – were subject to exactly the same caveats as were the so-called secondary qualities. From this they reasoned that, if such really were the case, namely that there was no difference between primary and secondary qualities, then everything would be ‘in the head’. And if everything were ‘in the head’ and things which were ‘in the head’, following the analysis of colour perception, were at best unreliable and at worst meaningless, then the robots could not be sure of anything at all. Yuk! Yuk! Yuk!

There was a brave attempt to rectify matters.

“Hold on,” said a hopeful robot. “We know the lines in the illusion are really the same length because we can measure them, and whenever we measure them they come out the same length.”

“No good,” retorted another robot. “You’ve got to use a ruler to make the measurements, so why should you believe your ruler rather than your eyes? The only reason you know your ruler exists, much less know of its supposedly invariant length, is because of the secondary qualities which impinge upon your mind.” (The robots had at last appreciated the significance of Impressionist painting to their debate.)

“Aye, there’s the rub,” chimed in a third robot. “It’s all very well to use a measuring apparatus, but any measuring apparatus is imperfect because we cannot know exactly what the measuring apparatus is like, and therefore we cannot know exactly what the things we are measuring are like. So, ‘seeing is believing’ works only if one has confidence in one’s measuring apparatus. Unfortunately, one can’t, so it doesn’t.”

Things had come to a pretty pass. To summarize, robot reasoning had arrived at the following conclusions:

  • All experience of the external world, or ‘out there’, is conveyed through the senses.
  • The senses sometimes deceive. No sense impression is 100% reliable.
  • There is always an ‘in here’ aspect to any sense impression.

From these it was a small matter to conclude that whatever the world ‘out there’ was like, it was a different world from the world of their sense impressions. This, the robots concluded, was a matter of logical inevitability. But, having got this far, they could agree on nothing else. And so the arguments started.

© Edward Ingram 1997

1 Claude Monet: French painter (1840-1926)

Edward Ingram teaches metaphysics and philosophy of mind in the School of Psychology at the University of Wales Bangor.

This site uses cookies to recognize users and allow us to analyse site usage. By continuing to browse the site with cookies enabled in your browser, you consent to the use of cookies in accordance with our privacy policy. X