I've spent the last 20+ years pondering the question of what I can know of reality, beyond the reality that perceptions exist. In college I completed majors in physics, philosophy, and mathematics. The philosophy major was a late addition, since when I started college I thought that physics equalled truth, and I planned to spend my life in physics or astronomy, thereby studying truth (as I then believed). Physics was my religion. The realization that physics was just an excellently successful model--perhaps modeling some underlying truth, but still just a model--ended my physics career. I couldn't go to the Church of Physics anymore, though I still loved the music and stained glass there, so to speak. I no longer had the fire to spend my life in physics or astronomy research, since it was no longer the pursuit of absolute truth. It is, however, still beautiful, and my telescope is my most prized possession.
The idea that "we directly perceive the world" is based on so many flawed assumptions that it would take a book to list them, not just a posting here, and I do not want to spend my life writing such a book. However, the first word, "we," is the first assumption. I assume that others exist, but I recognize that it is an assumption only, unprovable. If one accepts that assumption, further argument is possible, but each added assumption represents decreased certainty, and ANY assumption puts an end to absolute certainty.
Of course, I do assume the existence of a physical world, and the existence of others, and the existence of physical laws. If I did not, postings here would be an exercise in futility. And given the assumption of a physical world, I look for the most fully self-consistent model of it. When it comes to explaining the history of the universe, physics does a far better job than a literal interpretation of Noah's flood--which is the observation that drew me into this discussion to begin with.

• Thanks, again - harvey1 - October 21, 2002 - 04:12 UTC