Remember, your mind is like a parachute: If it isn’t open, it doesn’t work. So keep an open mind!

Keeping an open mind is a virtue — but, as the space engineer James Oberg once said, not so open that your brains fall out.

It pays to keep an open mind, but not so open your brains fall out.

Keep an open mind - but not so open that your brain falls out.

An open mind is really a mark of foolishness, like an open mouth. Mouths and minds were made to shut; they were made to open only in order to shut.

An open mind, in questions that are not ultimate, is useful. But an open mind about the ultimate foundations either of Theoretical or of Practical Reason is idiocy. If a man's mind is open on these things, let his mouth at least be shut. He can say nothing to the purpose. Outside the Tao there is no ground for criticizing either the Tao or anything else.

The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.

A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa, whether or not we like the implications.

Sir, there is a distinct difference between having an open mind and having a hole in your head from which your brain leaks out.

Merely having an open mind is nothing. The object of opening the mind, as of opening the mouth, is to shut it again on something solid.

Close-minded people have trouble holding two thoughts simultaneously in their minds. They allow their own view to crowd out those of others.
Open-minded people can take in the thoughts of others without losing their ability to think well- they can hold two or more conflicting concepts in their mind and go back and forth between them to assess their relative merits. p197

If we keep an open mind, too much is likely to fall into it

I have learned not to think little of any one's belief, no matter how strange it may be. I have tried to keep an open mind, and it is not the ordinary things of life that could close it, but the strange things, the extraordinary things, the things that make one doubt if they be mad or sane.

The world is complicated. Things are always changing. We are constantly learning, being exposed to things we didn't know or consider.

Our minds must be flexible and open enough to accommodate this.