Is there a reality that causes our experience? If so how can we come to know it?
There have been numerous naïve responses to these questions in the past. Most of these responses I believe come from an almost religious zeal on the part of certain academic practitioners who wish to present themselves to the laity as an authority. This in turn was probably encouraged by political powers who wished to supplant the legitimacy religious institutions gave them in the eyes of the laity with a new legitimacy based upon a certain formulation of reason.
One of these responses was the famous response by Samuel Johnson (the dude who wrote the dictionary!). I think he was talking about Hume when he kicked a stone and said “I refute him thus!” Now I don’t believe for a second that Johnson was an idiot but I must believe this if I am to believe he meant that statement seriously.
Basically the question: Do the feelings which comprise my experience come from “outside”?
A troglodyte could see that you cannot give as evidence for the claim “Yes they do!” feelings you have or have had. This is because the question concerns the origin of those feelings.
There is another stupid response to this question. That is “I know my experience is caused by something beyond it because other people confirm what I experience. I say I see an apple and you say you see an apple therefore there is an apple independent of us that causes our individual sensations!” This is stupid because firstly how do you know there is another individual beside you? I mean this is a problem even if we suppose there is a reality independent of us! How are any of us to know that someone else is conscious like us? What test can we do? There are none!!!! So to use as evidence something that requires more support than the thing we are using it to prove is inane.
The most intellectually honest affirmative answer to this question is: “There must be a cause for experience beyond experience because of the nature of nothing. Experience cannot come from nothing.” But even this is extending a law beyond its legitimate boundary. We discover that nothing comes from nothing through experience. That is to say that the law “nihilo ex nihil” is a proposition about experience. So the answer to the question “Do laws that hold in experience hold outside of experience?” becomes the foundation for the claim “Experience is caused by that which is not experience because nihilo ex nihil” I mean we have enough difficulty answering the question “Is there a reality outside of our experience?” let alone discovering the characteristics of this possible reality!