A fence within a fence

Question

There is a well known dictum that a lot of rabbinic enactments were created to 'create a fence' around the major sin; the idea being that if someone does something that would be Biblically permitted but might lead them to wind up doing something Biblically prohibited, better to make the secondary act prohibited, so that they won't wind up doing a Biblically prohibited act (I'm trying to come up with examples, but the only one I can think of offhand is that you're not allowed to tear off leaves from a tree because you might wind up tearing off branches from the tree - feel free to edit this if I got this wrong).

However, there is also an indication (if memory serves) that when we prohibit a tertiary act, we can be lenient in such a case. I.E. If we are worried that someone doing action Z will wind up doing action Y, and as a result will wind up doing action X which is biblically prohibited, we make actions Y & Z rabinically prohibited as well; if someone were to have a doubt about action Z, we have room to be lenient, because this is a 'fence within a fence'.

I then have two questions: 1) How far down are we obligated to go? In theory, you could add multiple layers of 'fences' (which ultra-orthodox people tend to do, for fear of coming anywhere near a prohibited act), but I can't imagine that these rulings are/should be binding on everyone who wants to follow G-d's law. 2) If someone were to break a tertiary (or a quaternary - yes, that is how you describe something at a fourth level - etc.) prohibition, are they liable for similar punishment as the primary or secondary prohibition?

Answer 1

Generally, the Rabbis enacted decrees that protect us from coming near Biblical prohibitions, but they do not enact "decrees for decrees", or what you call "fences within fences". There are exceptions to this, but it is a general rule, cited multiple places in the Talmud (e.g. Shabbos 11b).

There are several leniencies that are applicable to Rabbinic enactments, in contrast to Biblical laws, such as how we resolve cases of doubt, and for which considerations we suspend those laws.

The punishment for transgressing a Rabbinic law is almost never identical to transgressing the Biblical law it is intended to prevent.

A person is enjoined by the Torah to enact personal safeguards to protect himself from transgressing Biblical laws, however these aren't binding (unless an oath was undertaken) and are just a fulfillment of a positive command. See Moed Katan (5a) based on a verse in Leviticus (18:30).

Answer 2

You might be referring to the concept of דברי סופרים צריכים חיזוק. This means that we are more stringent with regard to rabbinic laws. This would sound as a direct contradiction to the famous rule that we don't mage a Gezeira to a Gezeira.

To answer this we must understand the idea of not making a Gezeira for a Gezeira (a fence of a fence) and Safek Derabanan Lekula (when in doubt about a rabbinic law we take the lenient approach). The function of these rabbinic rulings are as fences. Therefore they aren't inherently wrong. For this reason there is no Gezeira protecting you from the possibility of transgressing the rabbinic law. However, we are very much protective of the law being kept and not being taken lightly.

To illustrate this point, if there is a deep cliff near a school the responsible authorities would erect a strong, tall fence to keep people from landing up at the cliff. Now, if the fence got moved there would be no urgency to put it back at its original spot. The spot is arbitrary. It is there merely to make sure nobody lands up at the cliff. Likewise, there won't be any kind of protection from those who manage to reach under and over the fence. We won't either be implementing safeguards to make sure that absolutely nobody ends up by mistake on the other side of this fence, since that is not what bothers us — as long as the marked area is observed.

On the other hand, anyone tampering with the fence itself or trying to sneak through it would surely be stopped in his tracks. There is no doubt that this person is endangering himself and others by doing away with this fence.

The same applies for rabbinic laws. They might have created more stringencies to express the importance of keeping up the validity of these fences in general, but at individual cases we understand that it is not the spot near the fence that is being protected and that that is not what we came to avoid.