It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn't get confined, permanently blocked, as it has so many times before in various periods in the history of man.

This quote is saying that when people admit they don’t know something or they accept that they are uncertain of a situation, this can be seen as a sign of hope. It means that people can continue to make progress because admitting uncertainty or ignorance stops them from getting stuck in the same place, which has happened throughout human history. By being open to change and admitting when we don’t have all the answers, people can learn and grow together as a society.