My point is that if you don't have, somehow, direct evidence that animals don't speak Japanese when you're not listening then it's perfectly rational for you to believe that they are speaking Japanese. In other words, if you don't actually know something that contradicting a certain idea then it's rational to believe this idea is true.
That is incorrect though. You can still have EVIDENCE that the idea is *NOT* actually true, even if you do not have PROOF that it is not (such as if it contradicted itself). We can have evidence AGAINST THE IDEA that clouds in the sky are actually magical witches which pour water onto the ground below them (aka “rain”). We can make observations about what clouds are, about how they form, how they dissipate, under what other circumstances they do drop raindrops below them and in what circumstances they do not do that, etc. By making those observations about what raindrops are and what clouds are, it is not only rational and reasonable to conclude that they are non-magical phenomena, it is also irrational and unreasonable to conclude that they are. So no, you do not need to know with certainty some statement to be false, for it to be irrational to hold the belief. You can still hold strong evidence that the statement is false, without holding absolute proof that it is.
I see rationality as a capability that each individual has or doesn't have. Individuals don't have the luxury to wait for science to decide what was actually the rational thing to do. We're all more or less similarly equipped with our own portable survival toolkit of abilities. We use it as best we can given the circumstances we're in. Being rational doesn't mean being right, or even being mostly or most often right. Being rational is just being trusting of our perceptions and trusting of our sense of logic to boldly go where others may have never ventured. Most people don't have the luxury to spend their lives studying scientific theories and facts and yet they still have to make the best of an imperfect world and that's what they are trying to do.
We are [mostly] agreed on those points there.
You instead think of rationality as basically the scientific outlook and nothing else.
Eh, no. Science is just a more thorough, more knowledgeable, more productive, and less biased expression of the tool of rationality. Scientists have things such as academic journals, professional meetings, peer review, etc. to help make more accurate observations and deductions about the world around us. For most of us in our daily lives, we do not spend time doing that because it is not necessary much of the time, and a lot of people have various other interests and priorities to take care of. To decide whether or not I should take the garbage can out to the end of the driveway at a certain time, I make my own observations and deductions such as what day it is, how much or little garbage there is in the can, what time it currently is, what time the garbage truck arrives, etc. That level of rigor in the logical thinking works fine for that particular decision. I did not submit my thought processes to more rigorous scientific testing just because I did not need to.
If I wanted to make decisions about how to most reliably send a human being to the planet Neptune, I would need to be a lot more thorough in my observations, and what conclusions I can draw from those observations, submit those thoughts to others who have likewise done thorough research into the matter, and see what conclusions we can draw from each other’s thoughts.
So we all (try to) use the tools of logic, induction, and deduction in all of our lives to make choices and form opinions, but in some circumstances we are more rigorous than others in applying those tools.
Your view leads to systematically regard people who disagree with some scientific claim as irrational.
To be more precise, “people” themselves are not rational or irrational. People, rocks, trees, ants, buildings, et al. are a collection of certain materials organized in a certain fashion. It is actually *arguments* which those people hold which are rational or irrational. As a shorthand expression though, we often more casually say that certain people are rational or irrational, and that works fine in most everyday contexts and conversations. In this discussion though, for the purpose of clarity, we should try to remember the distinction between people (or even other animals) --- and the statements those people make, the beliefs they hold, the arguments they make to support those statements and beliefs, etc.
On some issue like what causes earthquakes, you can have a person named “Jane” who does a thorough amount of data collecting, observing of nature in various circumstances, exclusion of “selection bias” and other kinds of biases, submission of her ideas to peer review where others with vast background experience and knowledge can also review her methods and evaluate them. If they largely come into agreement that her observations were reliable and her deductions do not have logical fallacies, then we can consider that strong evidence that Jane was right. We would still be open to the idea that she is wrong, and be willing to change our minds based on new observations or if someone were to later find a flaw in the deductive reasoning. Besides, she may not be 100% correct on all of her positions, but even if she was still mostly correct, that would still be useful and helpful to us humans as we go through life.
Then you may have someone like “Elizabeth” who flips a coin to decide what beliefs she will hold on the matter of what causes earthquakes. She does not do the same rigorous data collecting, exclusions of biases, submission of her ideas for peer review, etc.
It would be irrational and unreasonable for any person (including both Jane and Elizabeth) to think that Elizabeth’s methods are just as reliable, and her conclusions to be just as accurate descriptions of reality, as Jane’s are. Flipping a coin is probably not going to give us accurate information about nature’s properties around us. People are not just “free to assume” or “free to believe” that Jane’s methods of formal scientific review are more reliable than Elizabeth's coin-flipping, but it is also RATIONAL AND REASONABLE to assume and believe that they are, even though we do not have absolute proof with certainty that they are.
Well, I for one disagree with the scientific claim that consciousness is likely to be fully explained in terms of neurons, synapses, neurochemicals and brain structures. So, according to your view, I have to be irrational.
That view would be irrational if other people have looked at it in more depth than you have, and have largely come to the opposite conclusion. Again though, it is viewpoints, beliefs, opinions, statements, etc. that people hold and people make which are either rational or irrational. Humans hold a collection of rational and irrational beliefs. No person is 100% rational or 100% irrational all of the time on every choice they make or belief they hold. Some people are just more rational or irrational in general than others though. We call people rational or irrational just as a shorthand expression, in more informal discussions.
Yet, as I see it, I'm not and I'm satisfied that I have looked at the issue in more details and depth than most people, so I think this makes my position perfectly rational.
“Most people” have not looked at the issue of what causes consciousness though, including doing research on neurons, synapses, neurochemicals, and brain structures. So it is kind of an irrelevant point that you have looked at it in more detail and depth than “most people,” when "most people" have done little to no formal studying of it at all. The more significant point is comparing your view to the people who actually have done research into the matter, have done formal testing and data gathering, who do engage in discussions with peers of theirs who have done similar research, etc. If they largely believe that your position is erroneous, we are not only “free to assume” and “free to believe" that they are more likely to be right on this issue than you would be, but it is also RATIONAL AND REASONABLE to conclude that they are more likely to be right.
Brian