Therefore anything that is subject to change is untrue.
A particular state cannot be true because state is always changing. You may say that it is true at a certain time, but we can never pinpoint what that time was exactly, and so we have to discard the state as untrue. Let’s think about the high jump winner at the Olympics who perhaps now holds the world record. We can say that this person can jump the highest in the world, but that may not be true tomorrow, it may not be true at the moment we say it. You will tell me, but at that time they jumped the highest and so it must have been true at least then. But then we must define what that time was exactly and all our measurement devices can only approximate, or give a range over, when any given time was.
We collectively agree, unconsciously, that time is fixed; but it isn’t in reality, and any physicist will confirm it. So time, as a changeable concept which cannot be, and has never been pinned down, must be untrue.
In fact, there is not one, solid, never-changing, singular instance of measurable time for anything, and there never has been. So the state of being the winner or the loser, the tallest or shortest, saddest or happiest, must necessarily be untrue. Similarly, everything we consider to be unquestionably true is in fact only a measure of where we’re at in terms of our current level of knowledge about the world. Things that we thought true in the same way in the past were debunked by newer ideas and research.
We are always rethinking and redefining the world around us; it is an on-going process of change and it is what we homo-sapiens do. It is a peculiar arrogance typical of humans that, in whatever epoch we have found ourselves - aside from a few notable folk who have striven under great pressures to open our minds wider, we have always assumed that the current consensus was the final word on it all, and have quite often behaved appallingly whenever it was challenged.
Let’s not forget that consensus world views of any past epoch are always successfully challenged, and amended or discarded completely. Therefore, due to the unlikelihood, given past experience, of our current beliefs remaining the same forever, we would be wise to discard these as untrue also.
We may talk about personal truths, i.e. something being true for me meaning it is not necessarily true for anybody else, ‘my truth’. We will again assume here that this sort of truth is not Truth. It is something else, preference maybe; not to be disrespected but to be understood as something other than real truth, which has to be true forever and for always.
The test of whether something is really true, then, is whether it is true eternally.
I do not attempt to define what this Truth is, but I hope to eliminate enough of what it isn’t to help point towards it.