Delusion and Reason

Drawn into the stream
Of undefined illusion
Those diamond dreams
They can't disguise the truth
--Level 42

At the beginning of his weekly letter, John Hussman proposes that delusions--such as those currently enveloping popular thought about financial markets, the economy at large, and Bitcoin--are not driven by failures in logic or reason. Instead, he suggests that delusional thinking results from 'distorted inputs' such as poor data gathering.

A different view is that the reasoning process includes front end activities that select and shape inputs for disposition by the human mind. If, for example, an individual exhibits a 'data gathering bias' that fosters collection of insufficient evidence that, when processed, leads the person to 'jump to conclusions,' then that person is not thinking rationally.

The reasoning mind understands the importance of information and evidence gathering prior to decision-making and will go to great lengths to ensure a sound basis for thought and judgment. The time and effort required to collect proper inputs is an important reason why humans tend to avoid reasoning process most of the time.

Claiming that delusional thinking does not reflect some deficiency in reasoning ability seems itself...delusional.