'Do you want us to go and pull them up?' He replied, 'No, if you pull up the darnel you might uproot the wheat along with them'.
This is the one text in the New Testament I am aware of in which Jesus clearly counsels us not to trust too readily in the way things appear to us. There is much we cannot be certain of in life, and so much about people that is always outside a comfortable range of certainty. We cannot be certain whether the darnel in our hand is really darnel; it might turn out to be wheat because they look very much alike. The converse is also true: we cannot be certain that what appears to be wheat is actually so; it might turn out to be darnel, which is poisonous at the roots.
This gospel clearly points out that there is a role that does not belong to us, and that role is the separating out the darnel from the wheat; separating out those among us who belong to Christ and those who do not. That can't be our role, for we simply do not have the requisite knowledge to make such inferences with a reasonable level of confidence.
My experience is that most people readily believe that if a hypothesis "makes sense", it must be true. A typical example in my own context as a teacher is the following: "If a student does not care about school, he will often be late for class. This particular student is often late for class. Therefore, he doesn't care about school." The conclusion "makes sense"; the problem, however, is it is not necessarily true. The teacher who fails to see that rushes to judgment, yells at the student, sends him to the office, and upon further investigation it is discovered that his mother is dying of cancer in the hospital, or he is suffering from clinical depression, etc. Students also tend to confuse truth with a hypothesis that makes sense out of the evidence. For example: "If the principal hates kids, he will walk around with a very serious demeanor. The principal has a serious demeanor. Therefore, he doesn't like us." The conclusion makes sense, but it is not necessarily true, for there are a number of possible reasons that might explain his serious demeanor - i.e., he's under all sorts of pressure that students are not aware of.
The large space between probability and necessity is something that most people outside the world of investigative science seem to overlook. If I were to define fundamentalism, whether it is the religious fundamentalism of the Muslim, Catholic, or Protestant, or atheistic fundamentalism (rationalism) or political ideological fundamentalism, etc., I would have to say that what they all have in common as a possible genus is the over-confidence in their inferences and the model through which they interpret the world, as well as a lack of awareness of the profound limitations of that model. Moreover, fundamentalists of whatever stripe always seek to create an environment that excludes anyone who is not of like mind.
The tendency to weed out the darnel in a community is rooted precisely in this desire for a secure and safe environment, one that is protected from conflict and from challenges that make us think. Human beings find uncertainty very uncomfortable, but the problem is we are more often wrong than we are right, and so if we succeed in creating safe environments in which only those who see eye to eye with us in almost every way are allowed to belong, we're never going to discover that we are wrong, at least not any time soon. Learning only takes place through a "clash of cultures", to use Karl Popper's expression.
That has been a problem in the Church in the past; a clerical culture was allowed to develop first in the seminaries, where only clerics taught young seminarians, where there were few women and lay people to learn from, and no fellow non-seminarian students to open them to larger perspectives, etc. Anyone who expresses any kind of doubt quickly becomes an object of suspicion and is in danger of being sidelined. That wasn't a healthy structure and the fruits were not all positive. But this is precisely the culture we find in many secular institutions today; there has been a new postmodern orthodoxy, which is why for a long time this country has discouraged a culture of debate - it has been very difficult to get my students to trust me enough to imagine difficulties and oppose me in class. Many in society are afraid to express their views on certain issues for fear of ridicule or prosecution and of being sent to "sensitivity training classes", etc.
These are all unhealthy signs that people are far too certain about their point of view and lack a healthy skepticism regarding the way things appear to them. And that's contrary to this gospel, which calls us to be skeptical of how human beings might appear to us at the moment.
The great physicist Richard Feynman referred to science as "an ever expanding frontier of ignorance". The more we discover, the more we realize how ignorant we are; our sphere of ignorance expands the more we learn. But that should be true for the rest of us, not just scientists, because most of the inferences we make every day are wrong - we just pay no attention to those mistakes, for they don't flatter us like accurate insights tend to do.
The good news is that there is no reason to be upset over the fact that we are wrong most of the time. This is how we learn, and we never stop learning. In fact, that's what it means to be a child. Children are constantly making mistakes, constantly exploring the world and discovering what they didn't know, usually by assuming one thing and discovering some other entirely unexpected explanation later on. It's wonderful to be a child, and Jesus said that unless you change and become as little children, you will never enter the kingdom of God.
But something happens to us during adolescence and young adulthood. We start getting things right, and we like the feeling. Soon we learn to forget our mistakes almost immediately after we've made them; we love certainty and begin to despise uncertainty. And that's why there is so much conflict in the world: everyone insists he or she is right, regardless of possessing only a cursory understanding of the issues. Very few are willing to debate or discuss, because there is a real fear of discovering they might be wrong, which in turn begets a fear of loneliness, among other fears. Unfortunately, many of us have lost that "child" in us that is okay with being wrong.
The other interesting point about this parable is that the angels will do the separating of the wheat and the darnel at the end. In other words, all will be well. Sometimes we are impatient to make things right, and when we attempt to do so, we make things worse. And so we need to trust that God is in control and that all things are subject to His providence. When our faith in providence is weak, that's when we begin taking on roles that are not ours to usurp. Our role is to do what God has called us to do, open ourselves to learning and stay open till the day we die, and to allow the frontier of ignorance to expand ever more widely in our lives. Life will become more exciting and more interesting, but that requires that we give up the arrogant disposition of the know it all and acquire instead the heart of a child.