No the feeling preference is not "rational" by definition
Correct me if I'm wrong, though is your real question "Can F types BE rational?"
My answer:
Of course!
Just like I used N about 6 seconds ago despite being an S a feeler can use thinking when necessary... they just prefer otherwise
Since we seem to have trouble locating our dictionaries in this thread, I took the liberty of looking up both words.
The definition of "rational," as defined by Webster's:
1 a : having reason or understanding b : relating to, based on, or agreeable to reason : reasonable <a rational explanation> <rational behavior>
2 : involving only multiplication, division, addition, and subtraction and only a finite number of times
3 : relating to, consisting of, or being one or more rational numbers <a rational root of an equation>
The definition of "feelings," as defined by the same:
1 a (1) : the one of the basic physical senses of which the skin contains the chief end organs and of which the sensations of touch and temperature are characteristic : touch (2) : a sensation experienced through this sense b : generalized bodily consciousness or sensation c : appreciative or responsive awareness or recognition
2 a : an emotional state or reaction <a kindly feeling toward the boy> b plural : susceptibility to impression : sensitivity <the remark hurt her feelings>
3 a : the undifferentiated background of one's awareness considered apart from any identifiable sensation, perception, or thought b : the overall quality of one's awareness c : conscious recognition : sense
4 a : often unreasoned opinion or belief : sentiment b : presentiment
5 : capacity to respond emotionally especially with the higher emotions
6 : the character ascribed to something : atmosphere
7 a : the quality of a work of art that conveys the emotion of the artist b : sympathetic aesthetic response
8 : feel 4
"Rational" does NOT mean "logical." It means "reasonable," which means "within reason," which means "not taken to the extreme." "Logical" means "valid," which can apply to anything considered to be "within reason."
"Feelings" does NOT mean "emotions." It also means "opinions," "thoughts," and "impressions."
Therefore, when you put the two words in their proper context, "feelings" can be "rational." This is the basis of the Feeling function; we rationalize what other people will rationalize about the subject. What thoughts and opinions people will have toward the subject. How they will
feel about it. ("If X happens, then people will think Y about it.") This is in contrast with the rationalization of a Thinker, which is generally focused directly on the subject. ("If X happens, then it will mean Y.")
As for the Thinker VS Feeler argument, both sides are right about one thing: their respective accusations against each other. The Feelers in the argument ARE immature and hypersensitive, and the Thinkers in the argument ARE insensitive pricks. If they weren't, there would be no "Thinkers VS Feelers" argument, because everybody would be too busy not giving a damn.
Feelers, you are NOT the Guardians of the Loving Heart. If you were that emotionally solid, you wouldn't get riled up every time a Thinker posts a thread slamming feelings as rational. It doesn't do anybody any good when one of you gets a hair up your ass because one Thinker didn't have his facts quite right. Swallow your pride and go do something else.
If you MUST post a rebuttal, do it with hard facts, not a river of tears. Thinkers don't pity; they respect. To earn their respect, you show them you're at least half as intelligent as they are. You do that by providing them with documented evidence to the contrary, not by flying into a rage and telling him he's an A-hole.
Thinkers, you are NOT the Grand Intellects of the human race. If you were that smart, you wouldn't engage in stupid arguments over who spouts the stinkiest bullsh*t. Check your egos at the door and stop belittling every Feeler that gets his panties in a wad.
If you MUST post a response, post "sorry, my bad" instead of sarcasm or a counter-argument, even if it wasn't your fault. Believe me, nine times out of ten, we'll drop the issue in a heartbeat. And you'll save on Advil!