Confucius (孔子), The Analects (論語), 13.3
Translation (Chad Hansen):
With regard to what he does not know, the superior man (the Gentleman) should maintain an attitude of reserve.
The worst thing that we can do to any person, organisation, or theory, is to speak about it with confidence when we ourselves are unsure about it, or have never verified the information received from non-authoritative sources (such as friends, family, mass media, and public opinions). (That being said, even authoritative sources are prone to make this mistake too! It is always important, therefore to verify.)
When we speak like this, we pass on misinformation which does injustice to the person, organisation, or theory.
One of the most common logical fallacies is known as the straw man argument. This is where a blatantly erreneous account (or sometimes, a slightly erreneous account) is presented instead of the actual account, thereby casting the person, organisation, or theory in a very bad light.
When we speak with confidence, we give the impression that we are imparting the truth. And people who hear this receive the message as truth. Yet, what this does is that it creates a prejudice against the person, organisation or theory.
Personally, I think this is one of the worst injustices which anyone could ever carry out. It is the worst because the person, organisation, or theory, has no opportunity to present his/its actual account and explain himself/itself. Or, even if the person, organisation or theory could do it, he/it would not be well-received because of the prejudices already formed in the mind of the listener. We do not simply create unnecessary prejudices, but we also block people from being receptive to the truth. We destroy the good reputations of people, organisations or theories; we deny them the opportunity to be heard by placing barriers in the minds of others.
To speak with confidence on matters which we are unsure of – and we are in fact, very unsure and even clueless about many things in and about life – is a serious act of injustice. And yet this is something which we do very often. Usually, we do this without even realising that we ourselves are uncertain about the things we speak about.
It is therefore important to reflect on what we know, and be aware of what we do not know. And what we do not know, or are uncertain, we should honestly and humbly admit uncertainty. We should not be too quick to speak as if we are experts or an authority on the subject, but take a step back and inquire about our own knowledge.
By doing this, one refrains from committing such acts of injustice by means of misrepresentation.
This will be the way of a true gentleman.