# What is Circular Reasoning?

by God_Delusion 36 Replies latest watchtower beliefs

• ##### Perry
it does not really shed any light on the question i raised, namely that a theory should be judged on how well it predicts nontrivial properties of the world.

I'm sorry Bohn, I thought that was an opinion statement. Could you please re-phrase that sentence into a question so I can understand your point?

BTW, please comment on whether or not you agree with Popper that a non-falsifiable theory isn't scientific.

• ##### bohm

Perry: Its not just an oppinion. To me proving something is true in the natural world means you want to talk about the probability that it is true because thats really all we can do. This view is the same as advocated by eg. Jaynes if you want me to slap a fancy name on it.

As i wrote, probabilities is a subjective thing and depends on your priors. what we DO have is a method of combining probabilities, basically bayes law, and i can point you to various proofs that show why this is a pretty fundamental thing.

I hope you agree with me so far - eg. that when you/me are saying "creation/evolution is true!" we really mean "the probability that creation/evolution is true is very very close to 1" and that it makes sence to talk about probabilities of something being true.

Now, we cant calculate the likelihood of creation or evolution in exact numbers. But we can, at least qualitively, answer questions like: "Does this observation increase or decrease the likelihood of evolution/creation". It turns out that the property we are interested in, in order of making the evidense relevant, is loosely stated: a) Does the theory predict/exclude the observation and b) Is it non-trivial.

So thats just my view. I think this is pretty compatible with Popper, as i think that if a theory make any non-trivial predictions, it is also falsifiable. For example, if my theory said: "Bananas are made of wood", that would automatically make it falsifiable. But i am no expert here, and i dont know if i impose more loose or more strict restrictions on what you would call a scientific theory than Popper does.

• ##### bohm

Perry: if i didnt make it explicit, my answer to your question is a resounding YES! So let me ask you back: Is the global deluge a couple of thousands years ago a scientific theory, and if yes - well, you know what i would like to ask next ;-)

• ##### Perry

We'll I'm glad you agree with Popper, so do I. Now let's grill up some dino beef cakes and have a party!

If finding a creature from today next to a dinosour falsifies evolution, you have a problem. There are many critters (alligators, mosquitoes, cockroaches, certain fish) that are found next to dinosours. Just that every time something falsifies evolution, an ad hoc excuse is created. So-called predictions are not the basis of science. In order for it to be science, it must be: measureable, verifieable and repeatable. As origens deals with history, neither idea qualifies as science.

• ##### LeeT

Firstly this is off topic so I'll keep it short.

Re this TRex tissue.

If dinosaurs were as recent as young Earth creationists argue wouldn't we expect to see more dinosaur soft tissue. The fact that we don't (this was the first of anything like this apparent age) indicates to me that dinos are definitely way older than the YE'ers say.

• ##### drwtsn32

It is interesting that the only people that seem to fight the various scientific dating methods are young earthers.

• ##### Perry

drwtsn,

Not true. Gap theorists allow for a millions year old earth, with young creation of everything else.

• ##### LeeT

Sorry, I'm off topic again.

I'll not post again on this thread.

I've found a couple of 2008 articles indicating that the TRex tissue isn't actually from the TRex.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2483347/

http://findarticles.com/p/articles/mi_m1200/is_5_174/ai_n28073075/

and an older article discussing Schweitzer's work and creationist misrepresentaation of it.

http://www.talkorigins.org/faqs/dinosaur/flesh.html

• ##### Farkel

In logic, you have assertions and conclusions arising from assertions. In real logic, if the conclusion must necessarily arise from the assertions, then the argument is logical.

Simply stated, circular reasoning is where the assumptions use the conclusion as proof of their own validity, and since the conclusion is assumed to be true, then the assumptions are also assumed to be true. It's like a dog chasing its tails.

In real logic the conclusions are ONLY derived from the assumptions and cannot be logical without them.

I am a man and only men have balls.

Joe has balls.

Therefore, Joe is a man

Is a logical argument.

Joe is a man with balls.

He must be a man because he has balls.

Is a circular argument. In this case, the conclusion is true, but the evidence to support it comes from the conclusion which is stated first. The evidence or assertion comes second, but uses the conclusion as its own evidence.

Farkel