There are certain arguments that appear to be true, but in reality they are based on fallacious propositions from the point of view of logic. These forms of inconsistent and misleading reasoning are known as fallacies. One of them is the argument ad ignorantiam, a Latin name that literally means "argument from ignorance."
This fallacy has a general characteristic: a statement is claimed to be true or false because there is no evidence to the contrary. In other words, the falsity of an idea or proposal is inferred because its truth has not been proven.
Illustrative examples
Someone claims that aliens do not exist, as no one has been able to conclusively prove their existence. Likewise, the opposite could also be affirmed: that aliens exist because no one has proven that they do not exist.
With regard to the existence or nonexistence of God, this type of fallacious reasoning is also common. Thus, it is affirmed that a god does exist because no one has proven otherwise and it is also said that it does not exist, since no one has definitively proven its nonexistence.
These two examples illustrate the ad ignorantiam argument, since in both reasonings ignorance about something is used to affirm a thesis. On the other hand, this reasoning makes a second error, since it is implied that everything that is not visible necessarily means that it does not exist. Thus, to say that "God is not visible and, consequently, does not exist" is a statement contrary to logic, since there are many realities that we accept as valid even though we do not see them.
Other fallacies
Argument based on the deduction of true premises leads to a true conclusion. Argument based on induction generates a probably true conclusion. On the other hand, when the rules of logic are broken, some kind of fallacy occurs.
If I affirm that 90% of the voters of a province have chosen a candidate and with this initial data I draw the conclusion that said candidate will be voted by the majority in the whole country. This flawed argument is known as the fallacy of hasty generalization.
When we discredit an idea using personal criticism of the individual who defends it. In this case the fallacy is known as the ad hominen argument.
Too often it is argued that something is correct because it has always been practiced. This argument is fallacious because it prevents any possible modification of the tradition.
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