I ask what is given and finally find that only that by virtue of which there is asking is given, i.e., the world is the only given. Merleau-Ponty refined this into the notion that the world is the truth. It follows that it is a concomitant of sentient life that the truth therefore has an outlook on the truth. The self sees the self. Man is a device whereby the real can gain self awareness. This is a kind of tautology. But consider that the individual’s point of view on the world is unique. New individuals constantly appear making discovery ever renewable. Each one is an existential mind/body instantiation of infinity for whom time and distance are uniquely relative. Then, we have something greater than a mere tautology. Each instant that the real is self identical it is nevertheless not the same real as before. Consider this as you ponder whether you can place your hand twice in the same river, or as you wonder whether a waterfall ever changes.
The scientific realist’s description of the world will never be final and definitive. There can never be a “grand unifying theory” of reality. Of space/matter? I doubt that too. One’s knowledge grows, yet the closer one approaches complete knowledge the greater the effort required to complete the final increments. And besides, knowledge is not the same as understanding and truth about the real itself in the end escapes precision. Material existence lends itself to measurement and science mistakes measurement for understanding, for truth. For attainment of true understanding that is fatal.