Insight is something very different to what we call knowledge. Knowledge concerns things that one can know for certain, such as the precise length of one's keyboard, whereas insight concerns matters that cannot be known for certain because they exist somehow behind or above the observed phenomena. Unless you are a scientist with a passion for learning the details of the physical world, almost everything that is interesting to think and talk about is in the realm of insight, not knowledge. In the realm of insight lie matters such as love, morality, meaning, beauty and God. One can never know anything about these things in the same way one can know the precise length of their keyboard, because one cannot observe them; yet one can feel them and intuit them. One rather has insight of them, an appreciation of their inward nature. Because one can never communicate this wholly to another person, it is necessarily a personal experience.
The problem arises when one attempts to communicate this insight to someone else. To take an example from our own database, it is said that talking about love is like dancing about architecture. We all know of a situation where the sheer strength of our feeling could not be translated into words, and that to attempt to do so would somehow sully and profane this feeling. Love is a concept, not something that one can see and measure; and so ultimately it is ineffable because no language can truly describe it, which is why the poets must resort to rhetoric and metaphors in their attempts. To put love into words is hence the domain of the poets, the people among us who are most adept at the manipulation of our feelings. Or it is the domain of lovers, who already intuitively understand each other so much that it does not matter what is said, but merely that it is said at all.
Philosophers and prophets have always been aware of the ineffable nature of that which they seek, and how language is ultimately not capable of encapsulating these things, which we feel more than we understand. This is why religion has consistently been understood throughout the ages, if not by everyone, as a personal relationship between a person and God; even if one interprets this relationship as imaginary, and hence a relationship primarily with oneself, the point is that the introduction of another person into the relationship through communication can only serve to destroy it. Those overwhelmed by the love of God become monks and take vows of silence, or speak in tongues that are incomprehensible to the rest of us, or otherwise withdraw from the world, as for them there is nothing that needs to be said and indeed nothing that can be said.
The same has almost always been true of the great philosophers, all of whom have acknowledged that their philosophy ultimately rested on something ineffable, something beyond description, that ultimately evaded them when they tried to pin it down. To be a philosopher means "to love wisdom", and these men were literally lovers of wisdom: they were enthralled by it, slaves to it, tending to its needs and pursuing it remorselessly and not once receiving truth in return. To understand philosophy as something that can yield ultimate truth is futile, for it ultimately rests on the contemplation of that which cannot be known or defined, and hence must be contemplated in the same way one contemplates the beauty of a rose or of God.
Hence Friedrich Nietzsche once wrote "One no longer loves one's insight when one communicates it". For the experience of insight - be it into the beauty of nature, your love for another person, or to have truly grasped the meaning of an event in a personal epiphany - is an experience between you and yourself, a feeling beyond language. As soon as we feel we immediately think and translate our experiences into words, but everyone knows that these words and the feeling are quite different things, that one takes place in the mind and the other in the heart, and that the depths and highs of the former can never match those of the latter.
To translate one's insight into words and communicate it to another is to sully it and cheapen it, to transform it into a medium that is not fit to express it. A confusion about what constitutes insight and what constitutes knowledge pervades the modern world due to the phenomenal advances that knowledge of the physical world via science has allowed us to realize in terms of technology. Everything that is "merely" beautiful or profound without being able to establish its own truth in the way that science can is seen as somehow lesser. Yet within this domain lie all of the truly interesting and urgent questions that concern humanity. These questions include how we should live at peace with one another, how we should structure our morality, and what we should value.
The products of insight into such matters are the books of revelation and the laws set down by the founders of our political systems. Just as one is not supposed to question the word of God as it was established by the prophets who claimed special insight into His nature, so did ancient customs and laws preserve in a communicable form the insight into political and social matters that was achieved by great thinkers. Charismatic leaders can create values and attract a following without ever having to explain in rational terms what it is they seek; for followers and leaders alike know what it is in their hearts, but cannot adequately express it in their minds. Just like we feel love much more than we can express it, we feel freedom and we feel equality in our bones; hence again it is the job of rhetoricians to express it.
This is not at all irrelevant to the ancient myths about a nation's founding fathers, a generation whose insight we apparently value so much that we never question or change the constitutions they created. Hence springs the feeling that to question such things is somehow not to be "patriotic", not to love the insight of one's ancestors. This situation seems ludicrous due to the plurality of nations, all worshipping their forefathers as the ones who knew the truth about political matters and how best to organize them - until we realize there is no reason they cannot all be true because there is no "knowledge" of such things, only original, necessarily personal, insight preserved through experience.
In a world that does not value insight and in which the products of former insight are ever more in question, we resemble a boat with a slowly decaying rudder, permanently adrift on stormy waters. The intricate and detailed knowledge of the patterns of the foam and the waves that our science gives us is no substitute ultimately for an insight into what lays behind the waves and the decaying rudder, what causes them to be as they are. Nothing can ever be proved about these things as causes cannot be seen in the same way that physical objects can, and yet their invisibility is all too likely to stop us before we even try. And try we must, while never falling into the temptation to dismiss something merely because it cannot be "proven".
One may no longer love one's insight when one communicates it. But love is ultimately the most selfish of acts, for it subsumes another individual or thing unto you and then blocks out the rest of the world - God, philosophy, and true love are ultimately the pursuits of loners or the lonely pair. If our societies are as broken as many fear, what is needed is a return of insight and those not afraid to believe in it; those to address the questions of what it all ultimately means - how we should live together, how we should be at peace, how can we love - rather than simply following the scientific mania to categorize all that there is. If these people love mankind more than they love their insight, they will do all that they can to share it with us. If they are not able to communicate it, then they must lead us by example. But they must hurry, for the worms have nearly finished their meal of the rudder.