Alan Crowe has a thoughtful discussion of how we use words to avoid confronting our doubts:

When we desire the psychological benefits of a false belief how may we obtain them? … use a clever, obfuscating phrase to push the doubts down into the subconscious. … Saying "I believe in God" muddles all the different religions together, dodging the question of what one actually believes. …

From each according to his ability; to each according to his need.

I think that is the classic because of the way it paralyses the intellect. There are all sorts of loose threads. Don’t we need an incentive structure to draw out persons’ potential. Aren’t abilities more like seeds to be watered and cultivated than assets to be seized. Are luxuries necessary?… The slogan is also a classic because it is such a feel-good phrase. There are lots of loose threads but we are reluctant to tug on any of them. They all hurt. Whichever thread we tug we are unravelling our snug woolly jumper and exposing our back to the cruel lash of reality. … Let me quote Clark Glymour …:

practitioners who have available only nonexperimental data often fudge the question of whether they are offering conclusions or hypotheses about associations or about causal structures, and equally fudge the question of what sorts of predictions their hypotheses entail. The language of science has changed to aid the ambiguity; thus conclusions of epidemiological studies are often stated, not in terms either of associations or of causes, but in terms of "risk factors," which sometimes mean one thing and sometimes the other.

Of course the hard question is: what clues we can use to see if our favorite slogans also function to hide our doubts?