People never had that ability in the first place. Getting to the truth requires a combination of factors, including:

• Looking at all sides of the argument

• Using logic

• Understanding the science/politics

• Understanding disinformation techniques by the government (character assassination, limited hangout, false testimonies, mass astroturfing, etc.)

• Reading everything (conducting a literature review)

• Personal or on-the-ground experience/research

• Pattern analysis

• Being open-minded, but at the same time requiring extensive proof for large claims

• Understanding that hearsay or an unsourced article/opinion is a weak reference. Assessment of individuals is required to judge the reliability of testimonial evidence

• Searching the primary source for every controversial claim and judging the reliability of that primary source

Most of the population won't look past a meme.