Part of my reason for posting about decision theory is to encourage people to realize that critical thinking is part of their everyday life and not some artsy theoretical musing. The need for such awakening came home to me again today when I read the letters to the editor in our local newspaper. Two issues of critical thought were laid to bare for all to consider, but probably most readers will be more swayed by emotion and prejudice than critical thinking.
Examining examples of how people make decisions in normal life can help greatly in understanding how to set up a flow of control in a computer application. If you cannot organize your life self-consistently, you might have difficulty trying to operate a machine that demands self-consistency. With that in mind, consider these exchanges of letters.
The first example involves the latest salvo in an ongoing argument between an active atheist and a devout religionist. The atheist had written that since we have no proof of a life after death, atheists value life more than religionists who tend to think of physical life as a staging ground for eternity. The response from the religionist was “If there is no life after death, how will atheists prove it? Atheists can only be proven wrong while Christians can only be proven right. How sad for atheists.”
I think it is even more sad for critical thinking.
Religious beliefs aside, there is no self-consistent logic in the religionist response. While it is true that theories about physical things can be disproved, but never be proven correct as mathematical theorems can, I know of no special dispensation which allows any religious claims to be excluded from failure. I think the sun will rise tomorrow, but that is not proven and cannot be an absolutely reliable prediction in the same sense that the sum of the angles interior to a triangle sum to 180 degrees (in Euclidian geometry). Still not many people would bet the sun will disappear tomorrow.
More insidious is the second example from the same paper. It is also the latest salvo in an ongoing battle in which some die-hard anti-evolutionists steadfastly maintain the stability of species and proclaim Darwin wrong. This letter is too long to quote completely. Suffice it to say the author is well-read and obviously intelligent, but unwilling to accept the robustness of the general concept of evolution as meaningful in spite of the self-consistent contributions of perhaps millions of scientists in dozens of disciplines in the last 150 years as can be confirmed by a quick Google search. Instead, the author states without documentation,”There is absolutely no proof determining that one species has arisen from another. In fact, there has been proof that species once thought to have evolved from another did not.”
The critical point in this quote is the contrast of the two sentences. Surely the second one is undisputedly correct. After all, that is how knowledge is accumulated. We sometimes make mistakes, and in good science, those mistakes get corrected. The second sentence could be taken as a support of the scientific method, and not a condemnation of Darwinism.
The first sentence is more troublesome. Its power hinges on the meaning of the word “proof.” Positive proofs of physical things are not possible in a mathematical sense (the sun might not rise tomorrow). Many examples of species evolution are readily available and highly documented, how much proof should we require?
Make up your own mind on religious, political, and scientific matters, but be careful of faulty arguments and changing definitions of critical concepts when people are trying to sell you things, including their view of the world.