Introduction
Ok, some of this may be hard to understand, but I'll try...
I'm skeptical about the reality of time.
Let me clarify before I get into this. The reality of time is different from the perception of time. Of course we perceive time, but I'm interested in the possibility of our perceptions being different from reality (of course they are...if they weren't then they would be infallible). Is time a property of REALITY or just our perceptions?
David Hume seems to sum this up very nicely. He attacks causality as being something that we can not know to be reality. Causality is summed up in our beliefs that state, "Every effect has a cause," and "Given similar conditions and causes, the same effect will happen."
Induction
To understand his argument, you have to understand the difficulties of inductive reasoning. Deductive reasoning is taking a principle (all dogs are mammals) and applying it to a specific case (Lucy is a dog, and is therefore a mammal). Inductive reasoning is the other way around...it takes several specific cases ("Lucy has four legs and is a dog, Leroy has four legs and is a dog, and Abby has four legs and is a dog) to form a generalization or principle (all dogs have four legs). I purposely used an example that ends in an untrue statement (it can still be a dog if it has three legs for example) to illustrate how inductive reasoning is never 100% accurate, unlike deductive reasoning. The reason for this is because we have only a few examples of specifics (we only know a few dogs) when the conclusion (all dogs have four legs) describes the complete set of dogs (all dogs that ever were, are, and will be). We have an incomplete experience of the entire set of dogs...we only know a few and have fallaciously attempted to make a generalization about all dogs from our limited knowledge.
The Problem:
The problem with the causal laws above ("Every effect has a cause," and "Given similar conditions and causes, the same effect will happen") is: "What proof or justification do we have for believing these laws?"
Hume reasoned that the only justification we have is that every event in the past has been consistent with these laws. We take every specific case in our past, see that they seem to have a causal effect, and conclude that every effect has a cause, and that given similar conditions and causes, the same effect will happen. However, this means we only understand causality inductively. We can't know the future, and so our knowledge of all events having to follow the causal laws is incomplete...we only know part of the set (the past), and much of it remains unknown (the future, and much of the past we don't know exactly what happened either). We fall into the same trap as our dog example above.
How This Relates to Time
Humans can only experience time through the perception of causality, which includes motion (call this sentence/proposition 'A' for future reference). An object stays in motion, so we keep perceiving time, only because it was in motion before. Its previous motion caused its present motion...and because causality is doubtful, then motion is also doubtful. If A is true, and we can doubt both causality and motion as being true properties of reality, then it is also possible that time is not a property of reality. However, I must admit that A can only be justified through inductive reasoning as well.
A Little More on the Problem of Induction
The problem of induction has been a major problem in epistemology and the philosophy of science. The most notable replies to the problem have been:
- Bayesianism, which basically states that induction doesn't lead to 100% correctness, but only a higher probability of being right. That when events which are consistent with an inductive conclusion occur, one should be more inclined to change one's beliefs to align more with that conclusion...your belief should be the one that is most likely to be true...and since we have so much proof for the laws of causality, versus not believing them to be true, then we should be more inclined to believe them.
- Karl Popper, who basically said that induction does not exist. We take a competing set of conclusions...then test them. If we find events that aren't consistent with one of the competing theories, then we discard that theory...we do this until we have the right theory.
Both of these theories, though, do not solve the problem of induction, they merely sidestep it:
- Bayesianism only says one conclusion is more likely...but this does not refute Hume enough...Hume would probably agree that causality is more likely then unlikely, but we have good reason to doubt it, and do not conclusively know inductive inferences to be true.
- Popper's view only works negatively...we can discard bad theories, but what makes us believe a theory? We still have an imcomplete set of possible theories, and just because all the ones we thought of, save one, have been discarded doesn't mean our sole survivor is right. We haven't thought of every possible theory to compete yet, and so we can not discard them all.
