Not that she wants us to be dumb sheep, unable to think for ourselves. Actually it's the opposite: she's cautioning us against what we'd now call (mis)information overload, and against little seeds of ideas, chance opinions "in the air" that we can't shake off. "I hate that political figure." "Why?" "He's bad. He hates women." "How do you know?" "Everybody knows that." Financial and real estate updates are particularly bad for delivering no real news at all: the market drops sharply, then comes back a bit, and the headlines shout about the "increase."
But if our own Reason can't be fully trusted to discern truth, then what other defense do we have? Only a sort of "long obedience in the same direction," an ongoing search for wisdom that the writer of Proverbs also stressed. "We must labour to get knowledge as the foundation of opinions," and "we must also labour to arrive at principles whereby to try [test] our opinions" (p. 59). If an uninstructed Conscience is "open to every prompting of inclination" (p. 61), then the opposite is true: an educated Conscience is solid, dependable. It is more aware of history, able to see patterns and parallels, because (it is also true) there is nothing new under the sun.
The strange thing about situations where stray opinions go viral, as we'd say now, is that they often lead to suppression of free thought and speech. Mason says that "the uninstructed conscience leaves its possessor open to bigotry, fanaticism, panic, envy, spite" (p. 67). I like her use of the word "panic" there. It reminds me of a local news source that over-uses the word "scramble" to amplify almost any story, making life sound like an ongoing game of candy toss. People are scrambling to get flu shots. Canada Post workers are scrambling to deliver the backlog of parcels. Christmas shoppers are (always) scrambling for one thing or another. If you can inject a bit of panic into the situation, it becomes more important, because we don't want to be the losers in the scramble!
And the opposite choice of words? Calmness. Slowness. Careful examination and study. The humility to know when we may be wrong, when the evidence shows it's time for a paradigm shift. But, also, the trust in tested principles, and in the One who laid them out for us.