Trump’s “truths,” as Alan Schrift, a professor of philosophy at Grinnell College, pointed out,

are not socially constructed but emerge from his own personal sense of what will promote his popularity, his power, and his wealth. This is why his particular, and acute, narcissism is so dangerous: he appeals to no social standards at all, only his own imagination as to what is in his own personal interest.

Read the full article, "Is President Trump a Stealth Postmodernist or Just a Liar?" by Thomas B. Edsall.