so the other day I talked about Descartes and the idea that we can’t really know with 100% certainty that what our senses tell us is true.
One of the commenters on my post on g+ responded:
Testable. Observable. Repeatable. Independently verifiable.
I toss a rock into the air, it falls. You toss a rock into the air, it falls. The rock falls whether I am looking or not. Your rock falls whether I am present or not. These observations can be recorded, exchanged, and define a shared reality.
which sounds great – we’re so used to regarding this as the way to verify objective truth that we don’t see the limitations of this method. My senses tell me that the rock falls. My senses tell me what the records of observations are saying. My senses tell me that I’m looking at a piece of paper on which someone else has written a record of their own observation. My senses tell me that another human being is standing in front of me and speaking, telling me their own observations of a rock falling. All these corroborations – they could all be part of my hallucination. So how can I really know for sure?
The answer is we can’t. There’s no way of evaluating our sensory perception without using our sensory perception, and we know that our senses can (and sometimes do) mislead us.
And yet, I do rely on my sensory perception in day to day life – we all do, because we need some kind of working assumption. We can’t go around with a constant awareness of this uncertainty. We regard it as reasonable to rely on our sensory perception, and I’d like to make it very clear that I’m not for one minute suggesting it isn’t reasonable. When I look out the window and see sunshine I don’t say “I see sunshine but this may be an illusion” – I say “there’s sunshine outside”: I interpret what my sensory perception is telling me and come to a conclusion about objective reality out there. I state it as true: “there is sunshine outside” – not as a tentative “in my fallible view” kind of statement.
And I act on these things – I take them as true and I base my actions on that assumption. If my ears tell me that I hear rain outside, and when I look out the window my eyes tell me that it is indeed raining, I reach for my umbrella and open it as I walk out the door. When I am sitting inside the thing which my senses tell me is my car, and I see a red light ahead of me, I put my foot on the brake and stop; when I see a green light ahead of me, I put my foot on the accelerator pedal and drive on. We do this sort of thing all the time, and it is perfectly reasonable behaviour, using the reasonable working assumption that what my senses tell me is very very very probably true.
And yes, it’s reasonable in appropriate contexts to add those extra factors such as: (a) I do X again and again and Y happens every time, therefore I regard it as reasonable to assume that Y always happens when you do X. (b) Someone else did X and observed Y. Several other people did X and observed Y. therefore I regard it as reasonable to assume that Y always happens when you do X.
Those things are reasonable ways of adding extra checks within our system of reliance on sensory perception. But none of this can provide us with 100% certainty, as it’s all dependant on our sensory perception, which can mislead us.
Why am I bothering with this stuff, if I am sane enough to agree that it’s reasonable to rely on our sensory perception in our day to day lives? Am I trying to play with your minds, to make you doubt what you’re seeing and hearing? Am I seeking to make you wonder if the sun really is shining/the rain really is falling/the snow really has snowed? No, I’m not suggesting that you start doubting everything. I just want you to start realising the limitations of those standards by which you seek proof for stuff in general.
I was talking to someone recently about God and as I talked about my conviction that the Bible is true, his reaction kept revolving round the same notion: how can you believe that stuff when you can’t prove it – and the way he wanted it proved was through those good old “reliable” means of observation (through sensory perception) and corroboration. I reminded him that our sensory perception is not infallible and he agreed, but he still kept repeating that demand. Because even though he could see that this method isn’t 100% reliable, he reckons it’s the best we’ve got.
I say it’s a really good method for lots of stuff, but not for everything. I’m not asking anyone to ditch it as a way of finding out if it’s raining outside or for working out the spread of diseases and discovering useful medicine, for instance. I think that’s totally reasonable.
But it isn’t reasonable to use that fallible method to evaluate the truth about God.
That method is good for some things but if you treat it as superior to everything else, and if you use it to evaluate absolutely everything, then there is some truth you will remain blind to. And I believe you’ll be missing out on the most important stuff you need to know.
I will come back and say more another day. Like I said in the previous post, there’s lots to unpack here. (Such as: what do we mean by “truth”? how can we find out this stuff? how can I be certain of the truth about God? Watch this space.)