There is general, though not absolute, agreement that being reasonable is good and being unreasonable is bad. Depending on how you define the terms, however, you can find more than one way to parse the differences between them.
I tried being reasonable; I didn’t like it. –Clint Eastwood
Some of the most awake and alive experiences of my life have occurred while I was trying to do things that were so outrageously unreasonable they seemed impossible to accomplish. Apparently, I like challenges. But that may just be part of my temperament. I was never particularly reasonable, even as a child—some might say especially as a child.
Some synonyms for reasonable are: sensible, logical, rational, moderate, mild, well-balanced, agreeable, and fair.
Some synonyms for unreasonable are: excessive, immoderate, illogical, irrational, extravagant, extreme, wild, and unrestrained.
A reasonable person is considered to be prudent and cautious, someone who avoids extremes. But reasonable can also mean mediocre, ordinary, average, and tolerable. And unreasonable can mean bold, daring, audacious, exceptional, and unexpected. An unreasonable person may keep going even after reaching reasonable limits. An unreasonable person may have unreasonable expectations—of herself and of others.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. [Or woman!] –George Bernard Shaw
Reasonable people tend to take fewer risks than unreasonable people take. Reasonable is often the safer course—but not always. Nor is it always the best course.
Dream no small dreams for they have no power to move the hearts of men. –Johann Wolfgang von Goethe
Creativity and reasonableness often don’t mesh, since being reasonable requires a degree of cognitive inhibition, while some stages of creativity require cognitive disinhibition.
Certainly you aren’t likely to be faulted for being reasonable and for refusing to accept unreasonable demands, requests, or challenges.
But remember that when you aim for reasonable, then reasonable is probably the best you can hope to achieve.
Tell me, what is it you plan to do with your one wild and precious life? –Mary Oliver