SnozzleBerry:
Allright allright, I am going to step down two inches, stuff an ice-cream into my face, cool off and talk from there.
From a very strict point of view, I realize that we cannot be certain about anything a hundred percent. This is also a philosophically completely valid position. I believe I have also expressed this several times before, but in discussions I am very colored by pragmatism and utility (because of me being a scientist), so I can rub you off the wrong way. But I don't wish to come off as arrogant or dogmatic, so I say it again here. Anyway, let me brainstorm on this subject a bit in my reply to you. This will be long, but consider it a trip into my thoughts and reasoning
In our discussions you seem to ask how we can know anything objective about the world when everything is observed through human consciousness and sensory experiences. One can also add on this the fact that we have no guarantee that we experience the world in the same way - and at least not in the same way as say, a dog. So how can we know anything objective about the universe at all?
The point - the intention - with doing science, logic and mathematics is that we can bypass this qualia and in principle describe our world independently of how humans subjectively experience it. To take some examples, we don't have to take into account the qualitative differences in the subjective experience of light to describe the electromagnetic spectrum; or the qualitative differences in the subjective experience of watching the stars to describe the fusion that goes on inside them; or the qualitative differences in the subjective experience of music to describe mechanical waves propagating through some medium. These are facts about the world that are not dependent on the individual human mind, but that exists free and independently from it - they are necessarily objective facts in, to my, any meaningful use of this word. They are not just correct within the restrictions of the human experiences of them, and therefore not only correct within a human application. Even though these methods can be said to be a human invention (or perhaps discovery) this does not in any way mean that what we discover and conclude through these methods also are human inventions, or at all restricts themselves to our species-specific subjective experience. In fact one can say quite the opposite; that these methods frees us from the limitations set on us by our subjective experiences - be that sensory limitations, false intuitions, cognitive biases and so on and so forth.
No one with their head not up their ass would claim that we know everything about the universe, but this doesn't mean that we can't say anything at all about anything, or that we can't talk about the likelihood of something being right or wrong. It is obviously a mistake, because it would be equal to saying that since we have just discovered a tiny fraction of what lies beneath the surface of the huge ocean, we can't say whether or not there is a skyscraper right outside my house. This applies to DMT as well, and with confidence we can, at the current stage of scientific development, say that no empirical or theoretical basis exists for assuming anything other than that we inhabit a universe made entirely of matter and energy. This is not a dogmatic position even though we don't know anything, because the essential point is that within our existing knowledge we do not have a credible reason to requiring anything else to explain what we experience and observe - yes, even when it comes to consciousness (even though the door to something else is open a tiny, tiny crack). All science is, however, provisional by its very nature, so if sufficient evidence that meets all the rigorous scientific tests were to come by and demonstrate the existence of a world beyond matter and energy, we would have to change our minds.
Now, what we read on the paper is certainly explanatory models to explain and predict observations, but what these models represents can still be argued to be independent of the subjective experiences of human beings, i.e objective facts about this universe. As an example, Newtons 2. law (though inaccurate at velocities approaching that of light) is not a subjective consideration; it is not open to guesses either between humans or other species. Actually this law follows directly from conservation of momentum, that again follows directly from rotation and translation symmetry (some physicists call this point-of-view-invariance), which means that the laws of physics are independent of who observes from where (Noethers theorem). They are objective. Of course the formulation of the law is human-made, but what it describes is still independent from subjective minds. Our experience of the natural laws can very well change, but the laws themselves do not.
It is also the fact that even though we can't disprove existential claims, it doesn't mean that the claims can't be unlikely. We can't, say, disprove the existence of gnomes in my shed or Santa Claus, but I bet you are not very hesitant to say that the existence of either is very unlikely. The same applies to DMT-entities, as we frequently discuss. There are no good reasons to assume they exist, and many to assume they probably don't outside your own drug-induced experience. We can't disprove that consciousness is not material of origin, but considerable evidence within our best scientific models and investigations suggest fairly strong that the phenomena of mind and consciousness arise from natural mechanisms in a purely material brain. Brain scans today can for instance locate the portions of the brain where different types of thoughts arise, including emotions and religious thoughts and experiences. When that particular part of the brain is destroyed by surgery or injury, those thoughts and emotions disappear.
On the subject of religious thoughts, emotions and experiences - or spiritual ones at that, it is now for instance well known that temporal-lobe-epilepsy results in visions that resemble such experience. Prominent neuroscientist V.S. Ramachandran has this to say in his book "Phantoms in the brain" about his observations:
"But most remarkable of all are those patients who have deeply moving spiritual experiences, including a feeling of divine presence and the sense that they are in direct communication with God. Everything around them is imbued with cosmic significance. They may say, 'I finally understood what it's all about. This is the moment I have been waiting for all my life. Suddenly it all makes sense.' Or, 'Finally I have insight into the true nature of the cosmos'".
Resembles DMT, doesn't it? He comments further:
"I find it ironic that this sense of enlightenment, this absolute conclusion that Truth is revealed at last, should derive from limbic structures concerned with emotions rather than from the thinking, rational parts of the brain that take so much pride in their ability to discern truth and falsehood".
Yes indeed, it would be really ironic if the great spiritual sages of history who have attracted billions of followers may all have suffered from temporal-lobe-epilepsy or some other neurological abnormality. Not only is these experiences physical in the brain and can be stimulated, destroyed and created by physical intervention - they may all be brain dysfunction as well.
I just find it extremely unsatisfactory and completely practical irrelevant to try to dodge all of this I have been writing so far by some metaphysical argument, as is often done here. You can create metaphysical arguments to dodge everything, but in the end - so what? The brain can still hallucinate, people can still get sick, people can get psychosis, gnomes in the shed are still not there to be found, the earth is still not flat and center of the universe, there is still no evidence to support anything beyond matter and energy and so on and so forth. In fact, these metaphysical considerations so often entertained to escape evidence and science don't really produce anything of practical significance alone at all, no new knowledge, no fundamental new insight except from the already should-be-obvious-fact that we don't know everything. Science justifies its process by its practical success, not by some logical deduction by some dubious metaphysical consideration. It has earned our trust by its repeated and proven success, whereas religion, metaphysics, in some extent a lot of spirituality have repeatedly failed us in drawing sound conclusions.
But I don't know in the end Snozz, neither do any of us. We could be all wrong, our models of physics could not be representing some reality out there by a rough shot at all, but what is likely? What is of practical significance in this experience? What can we assume and conclude without reasonable doubt? Where is the evidence going, and wouldn't it be reasonable and open-minded to follow it? Perhaps it is as you say - consensus is not objectivity, but to me it comes a hell of a lot closer than personal convictions, experiences, armchair philosophy, endless metaphysical circle wanks and drug-induced states of consciousness. Taking observations seriously, explaining them with models and predicting new ones is the best we have come up with through thousands of years of civilization and human experience - and look just how effective it has been.
Bah, enough rambling. But yeah, we do agree to a large extent in these questions, I guess you just take it one (or a few) steps further into a territory that really isn't my place of study being a scientist. This is also troubling to discuss because it involves terms and words that we may use in slightly different manners and context. Perhaps for other discussions we should make clear how we define and use terms like "objective", "material", "subjective", "consciousness" and so on to make it flow more smoothly.