This quote was also phrased, "The significant problems we face cannot be solved at the same level of thinking we were at when we created them."

I think that version does a little bit more in explaining the meaning. It means that we must develop our intelligence and level of thought if we are to find the answers to problems we create. He also said, "The important thing is not to stop questioning."

What he is saying is that we need to always strive to have a better understanding of things if we are to survive and prosper as a people.