Topic: Why agnosticism is unnecessary (Read 3026 times)

Anthony Horvath · « **Reply #20 on:** January 16, 2006, 08:24:17 AM »

Actually, Cop, you could say they USED to live in Plato's cave, but are trying maddeningly to converse with those still in it. :)

TheAtheistHeratic · « **Reply #21 on:** January 19, 2006, 07:17:23 PM »

Interesting debate!

Copernicus · « **Reply #22 on:** January 19, 2006, 08:36:06 PM »

Quote from: Cogito

Quote from: Copernicus
Quibble: absolute certainty that the conclusion follows or does not follow from the premises. Proofs can be valid but unsound. Deductive proofs are essentially a matter of syntax--moving symbols around in a way that preserves truth. If a premise is false, then the conclusion is not necessarily true.

I don't follow how this relates to the quote of mine that you replied to. I mean, this is all well and good, but the facts remain that inductive argument leads only to probable truth and that every argument we advance about the world is necessarily an inductive argument.

I just can't agree. Deductive proofs are based on premises that may be true or false. We may make a false assumption about reality and construct a valid deductive proof that leads to a conclusion.

Quote

This means, for example, that when Ragnar says that he believes that it is impossible for gravity to cease functioning, his belief is provably wrong.

Not necessarily. That depends on whether or not you agree with his premises and he has committed a fallacy in constructing his proof.

TheAtheistHeratic · « **Reply #23 on:** January 21, 2006, 10:15:42 AM »

Cogito · « **Reply #24 on:** January 21, 2006, 06:16:33 PM »

Quote

I just can't agree. Deductive proofs are based on premises that may be true or false. We may make a false assumption about reality and construct a valid deductive proof that leads to a conclusion.

True. If a deductive argument has true premises and is valid then the conclusion isn't just probably true, the conclusion is absolutely certainly true.

The point I make is not that deductive arguments cannot be false or invalid. On the contrary, they can be. The point I make is that a deductive argument is the only kind of argument that can possibly lead to absolute truth. Inductive argument can only lead to probable truth.

I pointed this out in regard to Ragnar's claim that "The force of gravity has never been observed to change, no matter what planetary body or star is being observed."

This is all well and good, but it doesn't mean that the force of gravity will not be observed to change tomorrow and it cannot mean that.

Any argument that contains a premise on which the conclusion rests which has to do with experience is always and forever only probably true. Only deductive arguments can lead to absolute truth. (This, again, is not the same thing as saying that EVERY deductive argument leads to absolute truth.) Therefore, when Ragnar argues that simply because we've never observed gravity to be any different than what we observe it to be today, it will never be different, his conclusion oversteps the bounds of the evidence provided.

We cannot say that gravity will never be different than it is today. We can say only that it is unlikely to be different.

Cogito · « **Reply #25 on:** January 21, 2006, 06:20:56 PM »

Quote from: Copernicus

Quote from: Cogito
This means, for example, that when Ragnar says that he believes that it is impossible for gravity to cease functioning, his belief is provably wrong.

Not necessarily. That depends on whether or not you agree with his premises and he has committed a fallacy in constructing his proof.

Yes, necessarily. His conclusion is based on a premise which relies on observation. Simply because every observation made in the past yields the same result does not entail that an observation in the future WITH ABSOLUTE CERTAINTY will also yield that same result.

The mistake that both you and Ragnar make is that you believe an inductive argument can lead to absolute certainty. It cannot.

Ragnar · « **Reply #26 on:** January 23, 2006, 10:38:27 AM »

Cogito, I've actually realized I have made a mistake in saying that gravity is true because we observe it working. It is really more than that. I might not be explaining it as clearly as I want, so bear with me.

Gravity is a logical necessity. If gravity ceased functioning, there would be no molecules, just a universe of atoms floating around, and hence no matter. It is a fundamental principle. The only way it could cease functioning is if you posited that it was created by a god, and that it was possible that this god could make it stop working whenever he wanted. If you take gods out of the picture, then gravity can not cease functioning by definition. To assume an agnostic position about gravity is to assume an agnostic position about everything, and results in having no knowledge about anything. It is an exercise in futility. It is the same as positing that we are all the dreams of a giant turtle.

We must base our knowledge on what we perceive with our senses and through rational thought. Anything else invites chaos and results in the death of knowledge. If you want to be agnostic about everything, that's your choice, but I choose to make distinctions between those things that can be proven within the framework of the material universe and those that can not.

TheDoctor · « **Reply #27 on:** January 23, 2006, 11:01:05 AM »

Quote from: Ragnar

Gravity is a logical necessity. If gravity ceased functioning, there would be no molecules, just a universe of atoms floating around, and hence no matter. It is a fundamental principle. The only way it could cease functioning is if you posited that it was created by a god, and that it was possible that this god could make it stop working whenever he wanted. If you take gods out of the picture, then gravity can not cease functioning by definition. To assume an agnostic position about gravity is to assume an agnostic position about everything, and results in having no knowledge about anything. It is an exercise in futility. It is the same as positing that we are all the dreams of a giant turtle.

As a former physics teacher I have a few points to bring up.

First, gravity is NOT needed for the formation of molecules, etc. Gravity is the WEAKEST (by far) of the fundamental (universal) forces. Gravity isn't even involved in holding molecules, atoms, etc. together. That falls to the other universal forces.

Second, recently the scientific community is re-examining our understanding of gravity. There is evidence suggesting that replusive gravity is at work in the supposed expansion of the universe. Do a google search for "dark engery."

Saying that gravity could not cease to function is an unscientific statement. Saying that we can be reasonably certain that gravity will function tomorrow would be a better statement. To make your original statement assumes complete knowledge of the universe (which science acknowledges as impossible).

Ragnar · « **Reply #28 on:** January 23, 2006, 12:32:01 PM »

Quote from: TheDoctor

As a former physics teacher I have a few points to bring up.

First, gravity is NOT needed for the formation of molecules, etc. Gravity is the WEAKEST (by far) of the fundamental (universal) forces. Gravity isn't even involved in holding molecules, atoms, etc. together. That falls to the other universal forces.

True, my mistake. But the same principle applies. It is illogical to posit that these forces may suddenly cease functioning.

Quote from: TheDoctor

Second, recently the scientific community is re-examining our understanding of gravity. There is evidence suggesting that replusive gravity is at work in the supposed expansion of the universe. Do a google search for "dark engery."

Saying that gravity could not cease to function is an unscientific statement. Saying that we can be reasonably certain that gravity will function tomorrow would be a better statement. To make your original statement assumes complete knowledge of the universe (which science acknowledges as impossible).

I don't mean to imply that we can have complete understanding or complete knowledge of the universe. What I am saying is the forces of attraction exist whether we understand them or not, and I see no reason to allow for the possibility that they may suddenly cease.

TheDoctor · « **Reply #29 on:** January 24, 2006, 10:13:17 AM »

Quote from: Ragnar

Quote from: TheDoctor
As a former physics teacher I have a few points to bring up.

First, gravity is NOT needed for the formation of molecules, etc. Gravity is the WEAKEST (by far) of the fundamental (universal) forces. Gravity isn't even involved in holding molecules, atoms, etc. together. That falls to the other universal forces.

True, my mistake. But the same principle applies. It is illogical to posit that these forces may suddenly cease functioning.

Quote from: TheDoctor

Second, recently the scientific community is re-examining our understanding of gravity. There is evidence suggesting that replusive gravity is at work in the supposed expansion of the universe. Do a google search for "dark engery."

Saying that gravity could not cease to function is an unscientific statement. Saying that we can be reasonably certain that gravity will function tomorrow would be a better statement. To make your original statement assumes complete knowledge of the universe (which science acknowledges as impossible).

I don't mean to imply that we can have complete understanding or complete knowledge of the universe. What I am saying is the forces of attraction exist whether we understand them or not, and I see no reason to allow for the possibility that they may suddenly cease.

Ragnar, your problem seems to be that you've mistaken our models of the various aspects of the universe for the universe itself. Our models say that these attractive forces exist but the models may be (or rather, probably) are flawed. There is now evidence that suggests gravity really can act in a repulsive fashion (or that there is a separate repulsive force out there). The electromagnetic force can also be repulsive.

Even though you claim not to have absolute knowledge of the universe your statement suggest otherwise.

Ragnar · « **Reply #30 on:** January 27, 2006, 08:51:09 AM »

Ragnar, your problem seems to be that you've mistaken our models of the various aspects of the universe for the universe itself. Our models say that these attractive forces exist but the models may be (or rather, probably) are flawed. There is now evidence that suggests gravity really can act in a repulsive fashion (or that there is a separate repulsive force out there). The electromagnetic force can also be repulsive.

Even though you claim not to have absolute knowledge of the universe your statement suggest otherwise.

I think you're still missing my point, or maybe I'm not articulating it clearly enough. The point was however the forces in the universe act, they will continue to act that way whether we understand them or not. It is not reasonable to suppose that the gravity of a planet in a stable orbit about a stable star will suddenly reverse itself and everything on the surface will go hurtling into space. If gravity can act in a repulsive fashion, that does not mean it will suddenly do so, say, at some god's whim.

What evidence is there that gravity can act in a repulsive fasion, by the way? In what context is it supposed that this happens? I've never heard of this and am genuinely curious.

cimics · « **Reply #31 on:** January 27, 2006, 01:23:45 PM »

http://www.advance.uconn.edu/2001/011008/01100813.htm

http://www.advance.uconn.edu/2001/011008/01100813.htm

http://www.pbs.org/newshour/bb/science/jan-june98/universe_2-27.html

http://www.cnn.com/TECH/space/9802/27/accelerating.universe/

http://www.lbl.gov/Science-Articles/Archive/Phys-SNAP-dark-energy.html

Ragnar · « **Reply #32 on:** February 03, 2006, 11:16:43 AM »

Interesting! It would make sense that gravity can both attract and repel, since every other force does as well.

But, how does this contradict anything that I've been saying?

Author Topic: Why agnosticism is unnecessary (Read 3026 times)