The fact that President Trump lies multiple times a day has become inescapably obvious to all but his most blinkered supporters. In that group of hard loyalists, his inveterate lying doesn’t merit direct refutation, just proper appreciation. Trump adviser Kellyanne Conway introduced us to “alternative facts,” which imply that the president does not see the utility of participating in our truth when his “gut” is much more reliably Donald-friendly. Rather, he operates alongside or above our truth through his own elusive discernment, always confidently doubling down. We, the benighted, are mired in a universe defined by science, history, and direct observation that clearly can no longer be trusted, since it is offered via “the enemy of the people” or “fake media” who, when challenging the president, deserve derision and dismissal.

Pathological lying, however, creates a dangerous reality that is important to recognize. Going beyond isolated falsehoods within the context of a shared reality, lying that comes from pathology creates an “alternative reality,” which comprises those “alternative facts.” And the more the creator believes his own lies, because of delusions, paranoia, or some other overwhelming emotional need, the more convincing they will be to vulnerable segments of the population. Thus we find ourselves in worlds-apart perspectives that elude reality-based problem solving: It is the sound of one hand clapping. Understanding why Trump lies is even more important, because once we fall into a malignant normality that defies healthy dialogue, we are deprived of the meeting ground of shared consensual reality.

Absent a thorough neuropsychiatric evaluation of the president, we may not know for years whether Trump asserts untruths out of a profound psychopathic personality structure or the intractable but historically successful habit of the chronic used car salesman or carnival barker. What we do know is that, if he falls in the former category, the public should be aware of the dangerous implications of his staying in power another two years. Mental health professionals analyze and interpret human behavior patterns in many ways outside of the more rigorous technical task of diagnosing, which usually requires a personal examination. In Trump’s situation, we have a lot more information about his dangerousness than almost any of the patients we have seen, given the voluminous high-quality data on him, including numerous personal accounts as well as observations in real time. For example, multiple sources generally agree that the president has lied an astounding 7,645 times during 710 days in office. ...

What we can say beyond doubt, however, is that he is unimpeded by empathy, duty, or shame and is wedded, in dangerous ways, only to what nurtures his exaggerated self-image. If he merely trafficked in condos and apartment buildings, he would threaten only credulous buyers. As things stand, his disregard for truth imperils our country and the world.