Occam's razor

What is known as Occam's razor was a common principle in medieval philosophy. The principle came to be named after the English philosopher and Franciscan monk William of Ockham (ca. 1285-1349) because of his frequent use of the principle.

Like many Franciscans, William was a minimalist in this life, idealizing a life of poverty and like St. Francis himself, battling with the Pope over the issue. William was excommunicated by Pope John XXII. He responded by writing a treatise demonstrating that Pope John was a heretic. Why get angry when you can get even?

In Latin, the principle reads: Pluralitas non est ponenda sine neccesitate or "plurality should not be posited without necessity." Those words have come to mean something quite different from what William meant by them.

William's use of the principle of unnecessary plurality occurs in debates over the medieval equivalent of psi. For example, in Book II of his Commentary on the Sentences of Peter Lombard, he is deep in thought about the question of "Whether a Higher Angel Knows Through Fewer Species than a Lower." Using the principle that "plurality should not be posited without necessity" he argues that the answer to the question is in the affirmative. He also cites Aristotle's notion that "the more perfect a nature is the fewer means it requires for its operation." Applying Aristotle's notion to the universe, one seems forced to conclude that no perfect being could reasonably be held accountable for its existence. In any case, Occam's razor has been used by some atheists to reject the idea of a god as the creator of the universe. To some atheists, gods are unnecessary pluralities. The existence and form of the universe can be explained without positing gods. William would not have approved of such thinking.

inattentional blindness

Inattentional blindness is an inability to perceive something that is within one's direct perceptual field because one is attending to something else. The term was coined by psychologists Arien Mack and Irvin Rock, who identified the phenomenon while studying the relationship of attention to perception. They were able to show that, under a number of different conditions, if subjects were not attending to a visual stimulus but were attending to something else in the visual field, a significant percentage of the subjects were "blind" to something that was right before their eyes.

Because this inability to perceive, this sighted blindness, seemed to be caused by the fact that subjects were not attending to the stimulus but instead were attending to something else ... we labeled this phenomenon inattentional blindness (IB).*

Mack and Rock go on to argue that, in their view, "there is no conscious perception without attention." We might add that visual perception does not work like a video or any other kind of recorder. Objects or movements may occur in the visual field that are not attended to and may not be consciously or unconsciously perceived. Things can change in the visual field without our being aware of the changes. Perception, like memory, is a constructive process, and it seems that the brain builds its representations from a few salient details, often determined by our purposes or desires. Thus, two people may witness the same events but see and remember quite different things, even if both are good observers paying close attention to what is going on.

illusion of understanding

The illusion of understanding occurs frequently due to selection bias and confirmation bias. By selecting only data that support one's position and ignoring relevant data that would falsify or compromise one's position, one can produce a convincing but misleading argument. By seeking only examples that confirm one's belief and by ignoring examples that disconfirm it or reveal the insignificance of the data you've put forth, one can easily create the illusion of understanding. The illusion of understanding is particularly prominent in the field of economic forecasting.

Economic forecasters employ a variety of methods and formulas. Some forecasters, some of the time, make  successful predictions, apparently on the basis of their methods. They appear to have identified real patterns in the market. The reality, however, is that all forms of successful economic forecasting are illusory because the economy is a complex system significantly affected by irrational forces (Thomas Kida: Don't Believe Everything You Think: The 6 Basic Mistakes We Make in Thinking). In short, there is no logical system that can predict the market because the market isn't logical. Anyone who thinks he has discovered a system that can "beat" the market is deceiving himself. (Note: "beating the market" means doing better than an index of funds, such as Standard and Poor's 500, over some period of time.)

illusion of justice

The illusion of justice is the notion that our natural sense of justice is the actual way of the world. Our natural sense of justice inclines us to approve rewarding good and punishing evil. Our natural sense of justice inclines us to disapprove of bad things happening to good people and good things happening to bad people. It goes against our natural sense of justice to see bad behavior rewarded or good behavior punished. If I'm kind to you, I expect you to be kind to me, and vice versa. I don't expect you to cheat me and you don't expect me to cheat you. In the real world, of course, it is quite obvious that good and evil are distributed indiscriminately among the good, the bad, and the banal, and cheaters regularly get away with their malfeasance. To correct the injustice of reality, humans have blinded themselves to it or created myths to explain it. Our various ways of blinding ourselves to the reality of our indifferent universe is the subject of this blog entry. I'll leave discussion of the various myths to others, though most readers are familiar with stories of divinities handing out rewards and punishments in an afterlife, misfortunes due to actions in a previous life, fatalistic philosophies involving some sort of power that has ordained everything to be just as it is for some indecipherable but good reason, goddesses of Fortune, Lady Luck, etc.

logical fallacies

Logical fallacies are errors that occur in arguments. In logic, an argument is the giving of reasons (called premises) to support some claim (called the conclusion).

There are many ways to classify logical fallacies. I prefer listing the conditions for a good or cogent argument and then classifying logical fallacies according to the failure to meet these conditions

fallacies of assumption

Every argument makes some assumptions. A cogent argument makes only warranted assumptions, i.e., its assumptions are not questionable or false. Fallacies of assumption make up one type of logical fallacy.

One of the most common fallacies of assumption is begging the question. Here the arguer assumes what he should be proving. Most arguments for psi (ESP and psychokinesis) commit this fallacy. For example, many believers in psi point to the ganzfeld experiments as proof of paranormal activity. They note that in many experiments a .25 success rate was predicted by chance but a meta-analysis found a success rate of .34. One defender of psi claims that the odds of getting 34% correct in these experiments was a million billion to one. That may be true, but one is begging the question to ascribe the amazing success rate to paranormal powers. It could be evidence of psychic activity, but there might be some other explanation as well. The amazing statistic doesn't prove what caused it. The fact that the experiment is trying to find proof of psi isn't relevant. If someone else did the same experiment but claimed to be trying to find proof that angels, dark matter, or aliens were communicating directly to some minds, that would not be relevant to what was actually the cause of the amazing statistic. The experimenters are simply assuming that any amazing stat they get is due to something paranormal. I call this assumption the psi assumption.

Another common--and fatal--fallacy of assumption is the false dilemma. Here one assumes that the only reasonable alternatives are the ones you present, when in fact there are others that should not be ignored.This tactic can be persuasive if one of the alternatives is clearly unacceptable.

Not all fallacies of assumption are fatal. Some cogent arguments might make one or two questionable or false assumptions, but still have enough good evidence to support their conclusions. Some, like the gambler's fallacy, are fatal, however. Odds for something with a fixed probability will never increase or decrease depending upon recent occurrences. If the odds were 50/50 before you flipped the coin, they'll still be 50/50 on the next flip--regardless of what side came up on the first flip or the last five or ten flips. (If the coin is loaded, the odds weren't 50/50 to begin with.)