So far no credible evidence can support the existence of ghosts. There numerous stories and many people believe in ghosts. For many people that is enough. We can think of ghosts just like any other phenomenon. That phenomenon may be gravity or ghost.
Science is the study of the world. We need to look at two basic questions.
- Is the phenomenon accepted by scientific establishment?
- Is the methodology used to test the phenomenon valid?
Examining phenomenon based on these criteria yield four possibilities:
- The gold standard is a phenomenon is accepted by the scientific establishment and methodology is valid. The phenomenon exists such as gravity.
- The phenomenon to be accepted by the scientific establishment, but the methodology is invalid. (e.g. data is incorrect or faked, the procedure was flawed). The phenomenon does not exist, but is wrongly accepted by science. The planet Vulcan was once thought to be real.
- The phenomenon is not accepted by the scientific establishment, but the methodologies testing the phenomenon are valid. The phenomena on exists, but is not yet considered sound science. At one point continental drift fell into this category.
- The phenomenon is not accepted by the scientific establishment and the methodologies to test the phenomenon is not valid. The phenomenondoes not exist. Mermaids fall into this category.
A phenomenon may move around the different categories depending on changes in the evidence, methods, or even death of older scientists.
So WTF does that have to do with ghosts?
Since ghosts are not accepted by the scientific establishment, we can eliminate the first two possibilities. At this point, even though ghosts are not accepted by the scientific community, they may still be real. We have to look at the methodologies that support the existence of ghosts.
There are many stories of ghosts. A ghost story is a testimonial. One testimonial is just as good as 10,000 testimonials. I love to listen to a good ghost story. A ghost story is not strong enough evidence to support the existence of ghosts. It is simply a good starting point.
So far the evidence presented by ghost hunters and such is just not believable. I am not going to try to debunk all the ghost claims. There are plenty of people who do this duty. If someone has some specific evidence, I would like to know. I do not know if I am qualified to evaluate it, but I may find someone who can. The most respected and only full time salaried ghost investigator is Joe Nickell. Here is some of his articles: Articles by Joe Nickell .
At this moment in time, I must conclude ghosts fall into category #4. The phenomenon of ghosts does not exist. If credible evidence presents itself, I will update my beliefs.
EDIT: clerical spelling