Is all of reality, in principle, accessible to us?

[DavidOdden]

Man is part of reality and has free will. It is impossible to know the course of action another person will choose. So yes, there are aspects of reality that man can't know.

Actually, this reminds me of a point that I wanted to raise, but forgot to. It is not hard to describe imaginary events in the remote past 40 billion years ago, which were not observed by any sentient being, and which did not result in any indestructable evidence allowing a valid inference to be made, let's say that a particular proton (call him "Ron") colliding with another proton (call him "Chris"). No human or other sentient being happened to witness this might-have-been event. We do have the potential for determining that such an event takes place in the present -- if we observe it -- but that potential is not retroactive. If reverse time travel is real, then the matter reduces to a simple observational question. If, however, it is in the nature of reality that there is no reverse time travel (my starting point, though Don may have counterevidence), then there are real things (unobserved events of the past) which cannot be known. The concept of the potential is again relevant. We have the potential to observe a Chris-Ron interaction and can come to a definitive answer whether they collided or passed by each other. But I would not say that we can actualize that potential, in every instance.

[Ed: spelling correction]

Edited August 16, 2005 by DavidOdden

[DPW]

If, however, it is in the nature of reality that there is no reverse time travel (my starting point, though Don may have cunterevidence), then there are real things (unobserved events of the past) which cannot be known.

No, reverse time-travel is impossible. When I said that nothing is unknowable, what I meant was that nothing is in principle unknowable.

[DavidOdden]

When I said that nothing is unknowable, what I meant was that nothing is in principle unknowable.

Agreed, but we need to be clear on what "in principle" means, since the impossibility of reverse time travel is principled. Specifically, when speaking of observations, "in principle" means "if the observer were present at the place/time required to make the observation".

[DPW]

Agreed, but we need to be clear on what "in principle" means, since the impossibility of reverse time travel is principled. Specifically, when speaking of observations, "in principle" means "if the observer were present at the place/time required to make the observation".

Yes, thank you for clarifying. The fact that nothing is in principle unknowable means that there is nothing which -- by its nature -- man's means of knowledge is incapable of grasping.

[Dufresne]

An individual's inability to predict the future does not equate to mankind's inability to know reality.

Why?

[colin]

Why?

Just to put it in context, you suggested that man cannot know all of reality because he cannot predict what another man might choose to do in the future. His actions are not yet a part of reality. Your suggestion was akin to saying that since man cannot know something that is not part of reality, he is unable to know reality.

I don't think that makes sense.

[Dufresne]

Just to put it in context, you suggested that man cannot know all of reality because he cannot predict what another man might choose to do in the future. His actions are not yet a part of reality. Your suggestion was akin to saying that since man cannot know something that is not part of reality, he is unable to know reality.

Suppose you inductively reach the principle that man is mortal. Does this principle apply to all men (past, present and future)? If the principle also applies to future men then aren't future men part of reality? What else - other than reality - can we know anything about?

[Teez]

Hi Don,

Before I can respond, I need some clarification on some things you have said in your post. Could you please explain what exactly is your position on what you have called "metaphhysically possible"? When you said

"Well, it doesn’t. In fact, metaphysical possibility is, in my view, an anti-concept that destroys the distinction between the metaphysical and the epistemological. It wipes out the principle that the metaphysically given is absolute, it leads to the analytic synthetic dichotomy, and it destroys our ability to retain knowledge of non-actualized potentials."

and then said:

"I say the identification of a potential, whether it is actualized or not, qualifies as real knowledge – it's knowledge about the identity of the thing that has the potential. If the metaphysically possible is the non-actualized potential, then the claim that we exclude the metaphysically possible from our epistemology is an error."

....so its a destructive anti-concept ...but excluding it from epistemology is an error? I dont get it, if you kindly explained that I can resume thinking.

Also could you please define what you mean by "existent"?

I believe then we can continue with your discussion.

thanks