The principle of indifference

In several previous posts I have applied the principle of indifference, albeit I did not call it by that name.

• In the post The eerie silence I wrote this:

The probability of the existence of extraterrestrial intelligence is 50%. As we know nothing, this is equivalent to throwing a coin, and if it comes up heads, we say that we are alone; if tails, that we have company.

• In the post Relativism in science? I said this:

If we have no reason to assume that a theory is true or false, its probability should be close to 0.5... Theories about which we have no information, for or against, with a probability between 0.4 and 0.6. I will cite the existence of extraterrestrial intelligence, the possibility of building strong artificial intelligence, or the various theories of the multiverse.

Relativism in science?

Karl Popper

As I have said in other posts, quoting Popper, a scientific theory can never be considered utterly confirmed. In other words, we can never be completely sure that it is true. But some people try to rely on this (and on Kant’s philosophy) to reach the conclusion that we cannot know anything about reality, that scientific knowledge is relative, and that science is no different from other human activities, such as arts or fashion, whose productions cannot be said to be true or false.

Against this position, in an article published in 1990 in defense of realism, Martin Gardner wrote the following paragraph, which in my opinion hits the center of the bull’s eye:

Ideology and contempt for science

The sentence against Socrates

In several previous articles I have warned about some of the dangers that are just now threatening the advancement of science, which has proceeded for over two centuries and a half. One of the most important is the dominance reached by certain ideologies with great political influence, that when their ideas are attacked on scientific grounds are oblivious to what science says, or just call it pseudoscience.

• It is a scientifically undisputed fact that the life of a human being begins at the fertilization of an egg by a spermatozoon. Despite what certain politicians and journalists say, there are no discussions on this issue in the scientific world. In a previous article I have summarized the scientific consensus, which has been unanimous for over a century and a half. Nevertheless, the proponents of a certain radical feminist ideology proclaim a right to abortion which in fact is the right to kill their children. If these abhorrent laws hold, it is due to the cowardice of the rulers, who do not dare to repeal it. The result is a step back in the defense of human rights. We are going back to the Middle Ages, when parents had the right of life and death over their children (this right is now granted to mothers). We are going back to slavery, when some human beings (the masters) had the right of life and death over others (the slaves). We are going back to the Roman Empire, when abortion and infanticide were legal until 24 hours after birth. Is this what they call progress? I would rather call it going backwards.