This statement has always given me difficulties. It seems to be playing with words. Of course we 'see' with our eyes, 'hear' with our ears. These organs are built into our bodies to allow our perception of some of the layers of the world around us. They are very limiting as far as what we can see & hear versus all there is to see & hear; they do, never the less, see and hear!
Again, to say we have no objective criteria seems to be going too far. We do have enough objective criteria so that we can all see a chair and are able to agree that it is a chair. A human smile will be interpreted for what it is anywhere in the world, no matter the culture. It's not that we are all seeing the exact same thing; we are not, as you stated. We are all able to see enough similarity to agree on what we are looking at.
There is a basic set of criteria known to most all of us. There has to be. Otherwise we could not function in the world with others.
Now this is a statement I can get behind! Beyond the 'basic database' we all carry there are depths of variation that are open to individual interpretation for every one of us. One fun example is a color test many of you may have seen. There is a bar of red in different shades of that color shown on a screen, how many shades can one see. Most women will see more shades than men. Woman have through the millennia, developed a better sense of variation in colors. And even within the individual sexes there will be some who will discern better, some less so.
I'm just not sure there is this concept of ultimate. Ultimate implies to me that there is one perfect "x" that is out there somewhere. Is there? Because we all perceive a variation of "x" that leads me to believe the closest we can come is actually the lowest common denominator rather than the perfection.
My focus has been on physical objects rather than something way more ephemeral as 'truth'. Hopefully to help make it clear where I am coming from. When we move into such concepts of morality and such, I wonder if there isn't that same 'basic database' of thinking where we can all agree on the generality of the principal. And then there is the variation principle within us all that breaks the principal down into layers of subtlety.
Spiritually and theologically, of course, most would probably suggest that there is those 'perfections' that would be considered the Ultimate. My difficulty with these concepts is that, like the gods themselves, these perfections are beyond mortal comprehension. Specifically these Ultimates are no more perceptible to us than the minds of gods themselves. As such, to me, they are in the same realm of reality, or not. They are an ideal that can not ever be achieved on this mortal plane.