R' Micha Berger wrote:
My understanding is that mesayeia is when the person was capable
of doing the aveirah without you. Not "would" but "could". Whereas
lifnei iveir is when the nazir is mei'eivar hanahar and you're
giving him passage.
The sugya is on AZ 6a-b.
...
I will be the first to point out that Lifnei Iveir is one the many topics where my learning and expertise is severely lacking. Even so, I suspect that there is something missing from RMB's definition. In the simplest reading of the pasuk (Vayikra 19:14), Rashi says that Lifnei Iveir forbids one to give bad advice to another person. It is difficult to imagine a worse piece of advice than telling Ruth to follow Orpah back her her previous god.
Googling the question "What is Lifnei Iveir" brought me to an interesting article by Rabbi Yirmiyohu Kaganoff (bio at http://rabbikaganoff.com/about) The full article is at http://tinyurl.com/ka3pwq6 and I would like to quote the part where he gives three different categories of Lifnei Iveir:
I. Inciting – maiseis
This occurs when a person was not even considering doing an
aveirah until someone encouraged him. Thus, the instigator incited
the performing of the aveirah and is therefore a maiseis.
II. Encouraging — chanufah
One violates this prohibition by complimenting someone for doing a
sin, thus implying that sinning is acceptable.
III. Enabling – lifnei iveir
One violates this prohibition if the sinner wanted to do the
aveirah, but was unable to do so without assistance. The person
who enables the performing of the aveirah violates lifnei iveir.
IV. Even when none of these Torah prohibitions are involved,
helping the sinner do the aveirah sometimes violates the rabbinic
prohibition of mesaya’a y’dei ovrei aveirah, assisting someone who
is sinning.
(It is unfortunate that the article did not cite a source or precedent for these categories, but please bear with me.)
It seems to me that RMB is giving a useful tool to distinguish between category 3 and category 4, but that tool is useful only in the case where a person already has the *desire* to commit a sin, but it lacking the *ability* to some degree. If a person has only a mild inability to sin, then the enabler is merely mesayeia; but if the person has a severe inability, then the enabler is placing a real michshol.
But what of the case where a person does *not* yet have a desire to sin? Rabbi Kaganoff is saying that one who incites or encourages him to do it is violating Lifnei Iveir. Even if the person already has the ability to do the sin, it was below his "bechirah point" until he was egged on to do it. Rabbi Kaganoff offers an example:
Inciting Someone to Sin – maiseis
The classic case of maiseis is when the nachash encouraged Chavah
to eat the forbidden fruit. Even though the nachash itself did
not eat, Hashem punished it for inciting Chavah to sin (Gemara
Sanhedrin 29a). Similarly, if Reuven incites Shimon to sin in a
way that Shimon had not considered, Reuven is a maiseis.
And so my question can be rephrased: If the nachash was wrong to tell Chava to eat the fruit, wasn't Naami wrong to tell Ruth to follow Orpah back to her god?
Akiva Miller
KennethGMiller@juno.com