I believe, but cannot prove...that reality exists over and above human and social constructions of that reality. Science as a method, and naturalism as a philosophy, together form the best tool we have for understanding that reality. Because science is cumulative—that is, it builds on itself in a progressive fashion—we can strive to achieve an ever-greater understanding of reality. Our knowledge of nature remains provisional because we can never know if we have final Truth. Because science is a human activity and nature is complex and dynamic, fuzzy logic and fractional probabilities best describe both nature and the estimations of our approximation toward understanding that nature.
There is no such thing as the paranormal and the supernatural; there is only the normal and the natural and mysteries we have yet to explain.
What separates science from all other human activities is its belief in the provisional nature of all conclusions. In science, knowledge is fluid and certainty fleeting. That is the heart of its limitation. It is also its greatest strength. There are, from this ultimate unprovable assertion, three additional insoluble derivatives.
1. There is no God, intelligent designer, or anything resembling the divinity as proffered by the world's religions (although an extra-terrestrial being of significantly greater intelligence and power than us would be indistinguishable from God).
After thousands of years of the world's greatest minds attempting to prove or disprove the divinity's existence or nonexistence, with little agreement or consensus amongst scholars as to the divinity's ultimate state of being, a reasonable conclusion is that the God question can never be solved and that one's belief, disbelief, or skepticism ultimately rests on a non-rational basis.
2. The universe is ultimately determined, but we have free will.
As with the God question, scholars of considerable intellectual power for many millennia have failed to resolve the paradox of feeling free in a determined universe. One provisional solution is to think of the universe as so complex that the number of causes and the complexity of their interactions make the predetermination of human action pragmatically impossible. We can even put a figure on the causal net of the universe to see just how absurd it is to think we can get our minds around it fully.
It has been computed that in order for a computer in the far future of the universe to resurrect in a virtual reality every person who ever lived or could have lived, with all causal interactions between themselves and their environment, it would need 10 to the power of 10 to the power of 123 bits (a 1 followed by 10^123 zeros) of memory. Suffice it to say that no computer within the conceivable future will achieve this level of power; likewise no human brain even comes close.
The enormity of this complexity leads us to feel as if we are acting freely as uncaused causers, even though we are actually causally determined. Since no set of causes we select as the determiners of human action can be complete, the feeling of freedom arises out of this ignorance of causes. To that extent we may act as if we are free. There is much to gain, little to lose, and personal responsibility follows.
3. Morality is the natural outcome of evolutionary and historical forces, not divine command.
The moral feelings of doing the right thing (such as virtuousness) or doing the wrong thing (such as guilt) were generated by nature as part of human evolution.
Although cultures differ on what they define as right and wrong, the moral feelings of doing the right or wrong thing are universal to all humans. Human universals are pervasive and powerful, and include at their core the fact that we are, by nature, moral and immoral, good and evil, altruistic and selfish, cooperative and competitive, peaceful and bellicose, virtuous and non-virtuous. Individuals and groups vary on the expression of such universal traits, but everyone has them. Most people, most of the time, in most circumstances, are good and do the right thing for themselves and for others. But some people, some of the time, in some circumstances, are bad and do the wrong thing for themselves and for others.
As a consequence, moral principles are provisionally true, where they apply to most people, in most cultures, in most circumstances, most of the time. At some point in the last 10,000 years (around the time of writing and the shift from bands and tribes to chiefdoms and states around 5,000 years ago) religions began to codify moral precepts into moral codes, and political states began to codify moral precepts into legal codes.
In conclusion, I believe, but cannot prove...that reality exists and science is the best method for understanding it, there is no God, the universe is determined but we are free, morality evolved as an adaptive trait of humans and human communities, and that ultimately all of existence is explicable through science.
Of course, I could be wrong...