StatGuy2000 said:
My intention in my post was to highlight that pseudoscientific beliefs are a long-standing point of concern within the American population (and no doubt in other countries) for decades, and belief in a flat Earth and conspiracy theories associated with it are similar ontologically to these other fringe beliefs.
Since the first definition of ontology deals with metaphysics, I prefer to constrain my analysis to epistemology, and more specifically, with the scientific method. I regard most questions of metaphysics as beyond the scope of the scientific method, an approach akin to Stephen Jay Gould's Non-Overlapping Magisteria.
StatGuy2000 said:
You do raise a good point about the distinction between "unproven" and "disproven", and a fair case can be made that the existence of the sasquatch is unproven, as absence of evidence is not the same as the evidence of absence. That being said, given the fact that the US has been thoroughly explored geographically and the fact that no tangible evidence of the existence of such an animal has been presented for the past 50 years or so does tilt the evidence pretty strongly against the existence. So even in this example, the belief in the existence of the sasquatch (irrespective of the current evidence) is fundamentally quite similar to the belief in the flat earth.
I disagree from an epistemological viewpoint based on the scientific method. The proper field of science to establish the non-existence of a living organism on Earth is population biology, which is at best an inexact science in general, and even worse when accurately assessing very small populations and determining non-existence. There are so many documented examples of organisms believed to be extinct (zero population) and later rediscovered, that at best one should consider claims of absence to be probabilistic for a given hypothetical species. In contrast, the proof that the Earth is not flat is about as close as it gets to absolute as exists in science. Some references:
https://en.wikipedia.org/wiki/Lazarus_taxon
https://www.care2.com/causes/10-animals-we-thought-were-extinct-but-arent.html
https://www.thoughtco.com/living-species-once-thought-extinct-4117748
https://www.independent.co.uk/envir...thought-were-extinct-but-aren-t-a6726221.html
http://mentalfloss.com/article/522682/5-rediscovered-species-made-headlines-2017
https://io9.gizmodo.com/ten-extinct-animals-that-have-been-rediscovered-5822783
StatGuy2000 said:
The case is even stronger for belief in alien abduction, and especially belief in astrology.
I presume you mean "against belief in alien abduction ..." The existence of hypothetical aliens on Earth seems subject to the same weaknesses as other cases purportedly showing that a given organism does not exist on earth.
Claims of alien abduction have a fundamentally different epistemology, because these are purportedly isolated events not subject to the usual scientific demands of repeatability. So there is an important distinction between what someone sincerely believes happened to them and what they can prove happened to objective third party observers. Since many of these purported abductions include purported involuntary sexual encounters it may be reasonable to use the same epistemology to investigate these purported assaults as we used to investigate purported sexual assaults by human assailants. Shall we conclude that the absence of evidence creating an inability to prove purported sexual assaults to objective third parties means the sexual assaults have been conclusively disproven? Of course, this is absurd.
Astrology is in yet another epistemological category, since it most commonly includes some supernatural assertions. Since supernatural assertions usually include claims of non-uniformity of natural law (miracles and spirit beings and such), they are outside of the realm of science to investigate. As Stephen Jay Gould explains:
Begin Exact Quote (Gould 1984, p. 11):
METHODOLOGICAL PRESUPPOSITIONS ACCEPTED BY ALL SCIENTISTS
1) The Uniformity of law - Natural laws are invariant in space and time. John Stuart Mill (1881) argued that such a postulate of uniformity must be invoked if we are to have any confidence in the validity of inductive inference; for if laws change, then an hypothesis about cause and effect gains no support from repeated observations - the law may alter the next time and yield a different result. We cannot "prove" the assumption of invariant laws; we cannot even venture forth into the world to gather empirical evidence for it. It is an a priori methodological assumption made in order to practice science; it is a warrant for inductive inference (Gould, 1965).
End Exact Quote (Gould 1984, p. 11)
Gould, Stephen Jay. "Toward the vindication of punctuational change."
Catastrophes and Earth history (1984): 9-16.
also see:
Gould, Stephen Jay. "Is uniformitarianism necessary?"
American Journal of Science 263.3 (1965): 223-228.
Gould, Stephen Jay.
Time's arrow, time's cycle: Myth and metaphor in the discovery of geological time. Harvard University Press, 1987.
So, in summary, the flat Earth theory is really much more definitively rejected by the scientific method.