Look at it this way:
Is the color seen by a protanopic (no red-sensitive cones) colorblind person "true" color?   (That's his view above, but it's not yours, since you are color "normal."  Probably.)  Is his statement that the three vertical planes of color blocks above (the ones going back from the plane of your screen) are not different from each other a "rational" statement?  You see the right-most, front-center cube as orange; is your opinion "rational" and his "irrational"?

Color vision is a metaphorical model for our question: Rational or irrational?

Human vision gives us an ephemeral shadow of perception of the wavelength of light.  It's extremely limited in range of wavelength.  It has only three out of a possible infinity of degrees of freedom.  It has virtually no polarization information.  It's profoundly colorblind with respect to the color seen by a bird, which has four, five, or six degrees of freedom.  A spectroscope has infinity.  Bees see the polarization while we can't.

Many kinds of perception are possible.  Each kind has its own kind of knowledge.  Any color "normal" person is certain that the vertical planes of colors are different.  If the protanope becomes certain, too, his certainty is of a different kind.  The color "normal" person "sees" the difference.  The protanope must deduce it.  A person who "sees" the direction of the acceleration of a handball as it bounces off the walls and hands in a handball court knows with a kind of certainty not recognizable to the majority–and that person "sees" a lot of physics that the majority may find "ivory towered and quite out of touch" with the real world.

The search for truth and the judgment of rationality needs to look at a great variety of criteria, and look with as many kinds of "insight" as can be discovered.

So when an argument appears to us to have error, we need to look for some specific error or errors of logic, or some specific missing element, or perhaps some identifiable false assumption or undue influence of wishful thinking, or some particular inaccurate observation, or some one or several viewpoints that have been left out, like a blueprint of a complex machine with only one projection. Or some collection of several of these.

We must look for alternative ways of looking because evolution didn't give us very many "perceptions" to start with.
 

Click on the graphic:

Human perception, human logic, and human knowledge are very far from being complete.	Assuming too few influences is at the root of many errors of logic.  An exemplar:	One of the simplest, and most important, concepts of physics is also one of those very seldom understood.	Observation and logic are woven together in effective use of knowledge.  Hyperlink thinking.

 

Is quantum mechanics "rational"?  Does it show that "Reality is only in your mind"?  Is the cat dead or alive?