A bit of background. I was having a sort of argument with a writer friend of mine over writers' imagination some time ago. We were discussing how African writers describe such colourful scenarios of nature and human conditions, and I thought it was most probably because they were living in that kind of environment so they are can paint that sort of picture more accurately and with much more ease. Then I went on to plug that philosophical argument mentioned above just to discuss the process of imagination, but my friend thought I meant that a writer can not describe something he has not seen so the argument went tangentially (and killed itself before it can do any damage)
If I try to sum up that argument in my own words, then it would go something like this. One can not imagine something which is entirely new to him/her, both in parts as well as a whole. For example, take the concepts of unicorn, fairies, God and Devil. Are they really as strange as we make them out to be ? Once we start breaking them down to the various parts it becomes a lot of more clearer. Consider explaining to a kid what a unicorn looks like: A horse (always white?) with a horn on the head. There. Could we have conceptualized this very notion of unicorns if we were not already familiar with what a horse and a horn looks like? It seems to me that the answer is 'No'. The same logic applies to the rest of the items in the list: Fairies, God and Devil. We take some physical forms (or not), mix them together and come up with a suitable figure. Then we take some properties, powers and/or abilities, mix them together, reduce or increase their magnitude, and BAM! we get a new creature/concept. Most (all?) of the figment of our imaginations can be deconstructed in the same manner.
Trying to come up a loophole for this theory, I thought about people who are blind from birth. Now their vision of the world is limited to what they can sense through everything but sight. What do they see when someone describes, for example, A ship sailing in the deep sea, with a storm brewing at a distance, the lone hero standing at the deck, looking at the sunset and thinking about his lost love. We all [people with eyesight or the ones who came across the concept of (ships, ocean, waves, winds, storm, sun, sunset/sunrise, love etc.) before they lost their sight] get different visions from this same description but almost all of them contain some form of a man dressed in [some dress based upon what you imagine a lone sailing hero to be wearing], a ship with white (black?) sails fluttering , clouds at distance, reddish sunset and image of a girl somewhere. The details may vary a great bit depending upon how much and to which section of fiction you were exposed to in childhood and teenage years. My question is this: What do blind people imagine when they hear a similar description, after one describes to them the various objects involved (ships etc). Which then brings me to the next set of questions. How do you describe such concepts to people who have never seen anything like that? How do you describe what a 'colour' is to a person who has never seen light? How do you describe 'light'? How do you describe anything to them and be sure the image formed in their mind is even remotely like the one in question?
Back to the philosophical debate: What do visually impaired people imagine? Is it anything like what people with eyesight do or something entirely different? Is it even possible to communicate it to someone like me who is used to seeing things based on how it appears in light and corresponds to the data processed by other sensory modes? Do they imagine some mental scenes when something like that is described.
I have read somewhere about the concept of knowledge from 'human gene-pool'. I am sure the a' priori and a' posteriori sets of knowledge figure in the solution somewhere. We do seem to know something at the time of birth - like numbers (not as English or Roman numerals but as: 'one' person holding me is different from 'those' standing there). We classify them as more, less, larger, smaller etc. later on, but we already have a concept of the difference between one and not one. In the same way, I think, its quite possible that we may have some vague idea of what kind of thing we are and how some things (numbers, shapes?) are in the world. Assuming that they have some concept of appearance, someone without the benefit of sight may think of something totally different from what you or I will, based on the same description, but what I would like to know is, Is it a total mix and match of the vague idea of appearance they have or are they able to imagine things which could not have possibly be accessible to someone without a sight. Some specific examples, Is it possible for them to think/imagine/dream a sequence with colours? Can they dream 'visual sequences'?
I am sure someone much smarter than me has asked all these questions in a better way, and probably answered them all too. Since I do not know anyone with visual disability well enough to discuss this, I am still in the dark as far as the answers are concerned. I think Google may help me when I am feeling a bit less lazy. In the mean time, for anyone unfortunate enough to end up reading this, I must apologize for my random musings but feel to discuss or post comments which may help to clear the matter for me.