What are the limits of my knowledge of the world?
For the last ten years I have “existed” in Japan. Within this time the nature of reality has not changed. This is as expected and is not surprising. I had lived in the three countries previously, and also extensively spent time in another country intermittently most of my life. The nature of reality holds true for all these places. I have also looked through the telescope at the International Space Station, the surface of the moon, Jupiter and Saturn its moons, Mars, and the light from distant stars and galaxies. As far as I can tell the nature of the reality is no different than to the one here on Earth. But that does not mean the nature of reality cannot be different elsewhere in the parts of the universe I have yet to observe.
What I can say is this: the nature of my immediate physical reality is thus, and that is all that matters.
Why should I need to worry about there being a different reality? For me, to function and operate in this world, this is all that I need to know – that within my world, reality is uniformed.
In the Cula-Malunkyovada Sutta, The Buddha said this when asked about the “deeper questions” of the nature of the world:
“[Your questions are] just as if a man were wounded with an arrow thickly smeared with poison. His friends & companions, kinsmen & relatives would provide him with a surgeon, and the man would say, ‘I won’t have this arrow removed until I know whether the man who wounded me was a noble warrior, a brahman, a merchant, or a worker.’ He would say, ‘I won’t have this arrow removed until I know the given name & clan name of the man who wounded me… until I know whether he was tall, medium, or short… until I know whether he was dark, ruddy-brown, or golden-colored… until I know his home village, town, or city… until I know whether the bow with which I was wounded was a long bow or a crossbow… until I know whether the bowstring with which I was wounded was fiber, bamboo threads, sinew, hemp, or bark… until I know whether the shaft with which I was wounded was wild or cultivated… until I know whether the feathers of the shaft with which I was wounded were those of a vulture, a stork, a hawk, a peacock, or another bird… until I know whether the shaft with which I was wounded was bound with the sinew of an ox, a water buffalo, a langur, or a monkey.’ He would say, ‘I won’t have this arrow removed until I know whether the shaft with which I was wounded was that of a common arrow, a curved arrow, a barbed, a calf-toothed, or an oleander arrow.’ The man would die and those things would still remain unknown to him.
The story tells us The Buddha’s attitude toward questions of irrelevance. What we need to know is immediately available to you through your senses and perception. This should be your starting point on the investigation into reality, whether you are Buddhist, Christian, Muslim, Jewish, Hindu, atheist, a philosopher or scientist or any other category of being I have not mentioned. For this is truly what is common among us, our senses and perception. Everything else is supplemental and, in my opinion, like noise in the data.