Rationality, as Wikipedia says, is:

Rationality is the quality or state of being reasonable, based on facts or reason. Rationality implies the conformity of one's beliefs with one's reasons to believe, or of one's actions with one's reasons for action. "Rationality" has different specialized meanings in philosophy , economics, sociology , psychology , evolutionary biology , and political science.

That being said can the concept of rationality have any meaning when we don't have irrationality in a fictional universe; when all men with thinking ability, act equally rationally as any other?

How would we define irrationality in absence of irrationality?

  • 2
    Unicorns don't exist but we can still define what they would be if they did. It seems reasonable to think that someone who is perfectly rational would understand what it means to not be rational, why wouldn't they be able to? They would just think of someone who doesn't have the ability to reason correctly. Sure, definitions often times are easy to understand when they compare and contrast things (light vs dark), but that doesn't mean we need to have something tangible that exists to understand what it would be like (the unicorn example).
    – Not_Here
    Aug 1 '17 at 21:32
  • @Not_Here But wouldn't empiricism pose a problem? What will happen in course of time? Humans tend to forget about something which doesn't have any use any more. Aug 2 '17 at 1:23
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    I'm not sure what empiricism has to do with this question. We think of things that do not exist all the time and we don't seem to have any problem doing it. If every person was born with two eyeballs, why would we have issues imagining someone that has only one? If there is a future where everybody has perfectly rational thought, why would it be impossible for someone to imagine someone who does not have rational thought? "Hey, you know how we all think in really clear and concise ways? How wild would it be if we didn't do that? I bet some crazy things would happen."
    – Not_Here
    Aug 2 '17 at 1:39
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    I would say just try to consider this: wouldn't it be rational to understand what rationality is? Wouldn't it be a clear way of thinking to understanding what thinking is and how to do it clearly? If someone understands how to think clearly they would obviously have the ability to think about the opposite situation. Wouldn't it be rational to understand the difference between rationality and irrationality? There's no use in a lot of things, like imagining purple unicorns, but we can still do it.
    – Not_Here
    Aug 2 '17 at 1:42
  • You should combine this comments to an answer! Aug 2 '17 at 6:03

I can't see much meaning for irrationality in this terrifying sci-fi dystopian scenario, except for the opposite of what everyone in this system does. If one were to propose a "rational" theory for anything, then by your assumption, everyone who surrounds this person would also agree that the theory is rational (presuming everyone has access to the same facts).

We could look from outside and notice behavior that seems irrational to us, and we might be able to have debates over whether such behavior is in fact irrational thanks to our fantastic ability to have varying types and degrees of rationality. But from within the world you propose, irrationality would probably just be defined as all behavior not exhibited by the rest of the group.


The question is either loaded or not well thought out.

Rationality implies the conformity of one's beliefs.

This means there is no standard definition for what is and isn't rational. It's subjective and circumstantial.

This is very much like asking If we got rid of all bad politicians, would politics still suck? Well.. what is a bad politician exactly?

Point is, you can't quantify rationalism so the question is moot.

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