I had this chat with a person on the net. It starts by me posting a paragraph from Reincarnation and evolution.

Me:		The gradual change we see between one species and another, both among now living beings and in fossils, can be explained by reincarnation, a gradual change of the consciousness of individual beings, reflected in the shape of their bodies. Darwinistic ideas are not the only ideas to explain that observation.
Him:		But even a thousand years ago it was argued that the ontological beliefs must be contained within the idea that only the natural can explain the natural. Reincarnation is the supernatural.
Me:		Why is it supernatural?
Him:		What is the proof for reincarnation that can be repeated and measured and replicated?
Me:		We can discuss that too, but why is reincarnation supernatural?
Him:		Give me one physical measurement for reincarnation.
		Prove it to me using the physical as a basis.
Me:		Is only the physical natural, is that what you mean?
Him:		By scientific standards. Beyond that it is more than a natural appeal.
Me:		Some things can today be measured and some can not. One that can not be measured today is for example strings, it is still a theory though, a popular one too, among scientists.
Him:		You saying that the physical theory of strings is equivalent to a physical theory of re-incarnation?
Me:		Only in the sense that neither of them can be measured today, yes. The aspect you discussed.
		My point is that to ask if something can be measured physically is not a strict criterium we use today.
Him:		For science it is.
Me:		Being able to measure something seems not a criterium for science to develop theories in a field and spend lots of time and effort studying it.
Him:		Then if physical replicated measurement is not a strict criterium, then everything is science.
Me:		No I don't think so, I think being able to construct a theory that makes some kind of sense, even philosophically, is important, like in string theory.
Him:		At least there has to be some sort of scientific basis to pursue the idea of re-incarnation. What is it, at the moment?
Me:		I would say there is enough material and theories about it for scientists to study the field, and some do.
Him:		So scientist are able to re-incarnate, like lower animals and stuff?
		I mean, if I walk into a lab and read a paper on re-incarnation I could re-incarnate living things?
Me:		Scientists who study reincarnation may not be physicists, but there have been studies made which do indicate that reincarnation takes place.
Him:		I would like to have the references to those studies that indicates that reincarnation takes place.
		But, I doubt they exist.
Me:		http://en.wikipedia.org/wiki/Reincarnation#Scientific_and_other_research_into_reincarnation
		Note that I have not said that reincarnation is a fact, I only say that the theory of it can explain some of our observations (like the gradual change of bodies), and that it is a theory worth investigating scientifically.
Him:		I just read the wikipedia article on reincarnation and I find it so anecdotally influenced to mean nothing, other than some one who is a Doctor worked on it. It is all useless to me, as far as the reproducibility and physical measurment and proper controls demanded of real science.
		It sounds like garbage to me.
Me:		The alleged reincarnation phenomenon is of such a nature that it is difficult to conduct an experiment on it, just like it is difficult to conduct an experiment on evolution, or on strings for that matter.
Him:		People conduct experiments on evolution all the time.
		One of the best one's was on the Galapagos finches over decades. They measured everything and every bird on this one island. And they found that the finches changed due to enviromental changes.
Me:		It is difficult to perform an experiment (or a direct observation) showing a change of species.
Him:		I like when Paul McCartney said that he and John Lennon had an agreement that when one died they would make contact. Paul said a few years ago that "John hasn't made contact yet."
Me:		And if he said "he contacted me yesterday evening" that single claim would of course mean nothing too.
		One would need to use statistical methods.
Him:		I think it would mean that we would have to question Paul more.
Me:		We need to collect observations and analyse them, just like any science.
Him:		Give it time. There are only so many biologist working on so few species; but I see a time when some cichlid or insect or bird is identified as a newly created species through that right combination of environmental change and biological interaction.
Me:		Right :)