(Latin: prae, before; judicium, judgment)
Judgment based on wrong or insufficient data.
It is that state of mind which decides on a matter either without due knowledge, or, what is worse, with erroneous knowledge.
Prejudice acts in two ways: it causes its victims to judge persons or things wrongly, and, moreover, blinds their reasoning faculties so that they are not open to conviction.
An illustration of this may be seen in parties opposed to each other in litigation.
Neither side sees the case in the light of the other; hence the necessity of a judge.
Prejudice is culpable if one does not use ordinary honesty and effort in order to know the facts of the matter in question.
New Catholic Dictionary