One of the hallmarks of the postmodern mindset is the refusal to believe anything is objectively true--or rather, that human minds can know what is objectively true. Thus the constant admonition to people who persist in the appallingly backwards notion of speaking with a semblance of confidence in a fact is to add words like "I think," or "I could be wrong but..." After all, if you can't know things for certain, why claim in your speech that you can? You're just being arrogant. Some (Brian McLaren comes to mind) believe that certainty is the cause of all the problems in the world both past and present. If only we could be less certain!
On one level, this is perfectly correct. Human minds being what they are, that is, both finite and fallen, they can never apprehend truth objectively or fully. There must always be an element of suspicion about conclusions made by human judgment, for the humble mind of man can, and often does, get things wrong. Therefore humilty is always needed in making a judgment. However, we cannot take this concept to its logical extreme, for there is another element in human judgment that must be taken into account: its being made in the image of God.
Because the human mind is made in the image of God, it is able to apprehend things. Perhaps not fully, perhaps through a clouded glass, but it can see things nonetheless. If it was always wrong, humanity would not be able to function or to put its trust in anything. As it is, one can generally trust that adding vinegar to baking soda will result in a chemical reaction, even if you haven't seen the reaction before. The human mind is capable of seeing results and in evaluating them, so trust in this conclusion about the effects of vinegar and baking soda is not unfounded. Of course, this is an extreme example, one capable of being proven in short order at any time. Other things, such as judgments about human beings or societal systems of religious beliefs, are not so certain and are definitely not so easily provable. Yet they also are able to be judged with some amount of accuracy, because the human mind has the capacity to discern good and evil and true and false with some degree of clarity.
So how do we judge judgments when we know our minds to be imperfect yet not unbroken? A simple solution, one that everyone uses constantly, is the Percentage Solution: if I am 95% sure of something, I am going to speak with certainty about it and am going to act concretely and with confidence upon it. There is no use in saying "I could be wrong but..." about an issue about which one is confident in and wishes to see acted upon. For one thing, it diminishes your authority when speaking. I am much more likely to believe you if you say "this is the case" than if you say "this could be the case, but I might be wrong." In other words, it creates a bad impression and is in very bad rhetorical form. For another thing, it diminishes your confidence in your own judgment and could well result in you becoming a fence-sitter on all issues, or, even worse, liable to be blown by any wind of the moment to endorse any conclusion. All in all, it's better to speak with authority and if proven wrong to retreat graciously. Children are easily persuaded to endorse any position that you take, because they in general trust their elders and do not have concrete principals with which to guide them. This a good thing for children, but in an adult is a very bad thing. "I left childish ways behind me," says the apostle Paul, and like him so must we. Convincing an adult to change his mind on an issue in which he is over 75% sure is a daunting proposition, and usually takes quite a long time. Of course, the things that we are 75% or more sure of ought to be chosen carefully, for sometimes the time doesn't exist to convince us. Military commanders with only one report on enemy movements shouldn't be 75% sure of what they are going to do, or else they may be unwilling to change their minds in time to counter their enemy.
However, even if one is only 50% sure of something, it is wise not to sit on the fence but to act upon that thing. If you are 50% sure that giving your sister a figurine for Christmas would not be appreciated, it is probably not worth a try to get one for her (I am 100% sure that this is not a good gift for my sister--which is why I got her one). If you are 50% to 75% sure of something, then it is probably a good idea to put in a qualifying phrase if the situation is right (Alan Greenspan is a master at this, but then in his field--economics--one is never more than 75% certain of anything). To use a religious example, if I am 60% sure that Calvinism is correct, I am going to try to attend a church that teaches Calvinist doctrine, but I am not going to avoid people who are not Calvinists. Judgments have consequences, but those consequences should be subject to the degree of certainty that one has.
This is only a rough guide, and there is no doubt much more that could be said on this issue (for a further discussion of postmodernism and epistemology, D.A. Carson's "The Gagging of God" is an excellent starting point). In all ages wisdom must correct the overreaches of the time; in the modernist era, a hermeneutics of suspicion was helpful: in the postmodern era, objectivity and the human capacity to know must be affirmed. And even now it appears that postmodernism is falling out of vogue; although what might replace it is anyone's guess.
There are exceptions to this: in the Bible we are assured that we may be certain of some things, and that prolonged doubt is a sin; thus Luke writes his gospel so that Theophilus may know the "certainty of the things that you have been taught." The confirmation of the Spirit gives us certainty; yet always the weak human nature has that niggling doubt, which will probably not be excised until the resurrection.
A Bit of Latin
Homines magnae virtutis tyrannos superare audebant.
Homines: "men," third declension masculine noun in the nominative plural.
Magnae: "of great," adjective modifying the noun "virtutis," in the genitive singular.
Virtutis: "character/ courage," third declension feminine noun in the genitive singular.
Tyrannos: "tyrants," second declension masculine noun in the accusative plural.
Superare: "to conquer/to overcome," verb in the infinitive.
Audebant: "used to dare/ were daring," verb "audare" in the third person plural imperfect.
Men of great courage were daring to conquer tyrants.