Strictly speaking, a lie is an intentional falsehood, something you say to mislead someone deliberately. If you actually believe the falsehood you're perpetrating, that's not technically a lie. But, in that case, does your false belief render your statement ethically defensible?

Consider Trump's assertion that climate change is a Chinese hoax. Given Trump's worldview and his limited background knowledge, this statement probably strikes him as true. To him, it's "truthy." There is, of course, a mountain of evidence to the contrary, but Trump would not have examined it. If Trump actually believes this falsehood, does that render this assertion less egregious?

In 1887 William Clifford argued in his famous article "The Ethics of Belief" that we are obliged to base our beliefs on sufficient evidence. To assert a belief in the absence of sound evidence is a breach of ethics. Trump does this routinely and habitually. He may actually believe many of the falsehoods he declares, but we all know that he neglects the due diligence required to validate those belief. That, in my view, is every bit as pernicious as lying.

I'd argue further that citizens who accept Trump's falsehoods uncritically, basing such acceptance only on what they learn from biased sources such as Fox News and Breitbart, and universally rejecting all other sources, are equally at fault.