Tension: Hold to What is True and Reject what is False

We live in a world where in the heat of argument you can hear the phrase: "That's your truth, not mine!" yelled at you because the other person does not agree with you. But the concept of personal truth is incoherent. We can certainly have personal opinions and these may or may not have objective truth, i.e. conform with reality. It is important to realize however that truth is, in fact, only another word for reality.
Statements only have truth value because we can make counter-factual statements. It is raining when it is not, or it is a nice day when it is really a miserable day. The second statement is more likely than the first to be questioned. Realistically a "nice" day must answer the question "nice for what?" That rainy day may be a nice day for ducks but not such a nice day if you don't care to get wet.
Some predicates cloud the issue of truth by being so conditioned by taste as to be mere statements of preference. The Romans had a phrase: De gustibus non est disputandum. There is no accounting for taste. I can tell you what my taste is and you cannot dispute with me about it. It is my taste, not yours. If I like peanut butter and horseradish sandwiches, well that's my business. We get into a good deal of difficulty if we mistake the two realms however of taste and objective truth.
We can easily find ourselves disputing about matters of fact as if they were matters of taste. A statement about reality is only meaningful if it can be confirmed. There are statements which may be true or false which can not be confirmed.
Mortimer Adler in his little book Six Great Ideas deals with the idea of truth at some length. In chapter 7 The Realm of Doubt he points out that judgements about truth are also judgments about the degree of doubt that can be admitted. There are very few things of which we can say we are absolutely certain. There are a great many things of which we are practically certain.
We need to make the distinction that truth is not about our certainty which is almost always short of perfect, but about the external reality. We may doubt all we like whether Tasmania exists, but it either does or it doesn't. Confusion about states of mental awareness ought not to be confused with truth and falsity. The cosmos cares not a whit about whether we believe something is true or false. It will go on as it is regardless. Perceptions are not the same as truth.
Adler makes an interesting statement. He says: "To whatever extent history, science, and mathematics have a future, to that same extent these bodies of 'knowledge' belong in the realm of doubt, not in the realm of certitude."
What does he mean by that? Truth is changeless because it is reality so if there is more to be learned it is only because some things remain to be discovered, hence currently in the realm of doubt.