If men possessed wisdom, which stands in the same relation to the form of man as the sight to the eye, they would not cause any injury to themselves or to others; for the knowledge of truth removes hatred and quarrels, and prevents mutual injuries.

Meaning: Someone's belief may have been produced by what they want to be true, rather than by good evidence that it is true.

Meaning: An outward container does not establish the quality of what is inside. Look for evidence about the substance rather than relying on packaging, appearance or a reassuring presentation.

Meaning: A request made at a higher level leaves room to reduce it later. The saying describes flexibility in an opening demand, while its advice needs limits: an inflated request can undermine trust or ignore what the other person can reasonably offer.

Meaning: A measure can register one property without recognising the differences that matter for another judgement. Equal weight does not mean equal value; choose evidence suited to the question.