There are many common examples of ‘geneivas daas’: It is forbidden to copy
other people’s tests, or to give homework to the teacher that was actually
done by someone else since that involves deceiving the teacher. Similarly,
changing the grade of a test, and forging a certificate are forbidden,
because doing so can enable one to get a job or position when they don’t
really deserve it. In this case, as well as ‘geneivas daas’, one
transgresses ‘geneivas mammon’ (stealing money) and ‘sheker’ (falsehood).
As we have said earlier, it is also forbidden to ‘gonev’ the ‘daas’ of
non-Jews, this includes cheating the Government.
The gemara in Megilla says that one should always quote something in the
name of the person who first said it. By not doing this one also
transgress the Mitzva of geneivas daas, because in this way, the people
think that the speaker thought of the idea when that it not the case.
However, when one argues with someone, he does not mention the name of the
person because he does not want to embarrass him.
Overly praising someone with qualities that he does not possess, may
constitute geneivas daas. It would seem that it’s dependent upon how much
the person exaggerates in his praise. However, nowadays, since it is
commonplace to use excessive praise, there is generally no prohibition.
1. This article is based on a talk given by Rabbi David Genish, Shlita, Rabbi of Kehillat Meam Loez.