9/2012 It's all in the stars

Post hoc ergo propter hoc

I was reading the book "Astrology, belive it or not ?" by S. Balachandra Rao (Pub.: Navakarnataka Books, Bangalore, India). People who study formal logic, are aware of the term "Post hoc ergo propter hoc". Post hoc ergo propter hoc, Latin for "after this, therefore because of this," is a logical fallacy (of the questionable cause variety) that states, "Since that event followed this one, that event must have been caused by this one." A subtle variant of this fallacious wisdom is the fallacy called "cum hoc ergo propter hoc", in which the chronological ordering of a correlation is insignificant, yet the events are given a cause-effect relationship.

It is commonly seen that we often observe two unrelated events and conclude that one caused the other. This class of examples is sometimes called the "Rooster Syndrome": "believing that the rooster’s crowing causes the sun to rise". Another example of such fallacious logic lies in statements like :: "A black cat crossed my path, so I missed the train" or in the conclusion that "Bob was in the same train as Alan, so Bob is Alan's murderer".

The most ridiculous usage of "Post hoc ergo propter hoc" is in astrology. The bunkum extends to correlating the relentless motion of planets, to earthly phenomena. A planet's position, as seen from the earth, against the backdrop of some arbitrarily chosen bunch of stars decides whether your favourite horse will win the jackpot or not. Planets have always been moving in the skies. People have always been betting on horses. Why not link these two phenomena ? You dont need to know Latin, or know formal logic, to see the farce called astrology.

The day of the week, when a child is born, will decide whether or not he will win the Nobel Prize. "Einstein was born on a Wednesday, so he won the Nobel Prize". How about all those who were born like Einstein, but did not get the Nobel ? Or, all those who got the Nobel Prize but were not born on Wednesday ? Never mind the hard work the surgeon puts in, to save a life. The patient died because the stars were not in the right place or in the mood to let him survive. "It's all in the stars", says the all-knowing astrologer, to console the dead man's widow. By interspersing their discourses with astronomic jargon and mumbo jumbo they can confuse even the staunchest of astronomers.

When will people learn to use common sense ?

***