He explains that the reason the Gemara ultimately rejects the kal vachomer is because the Amora'im decided that the function of birchas hamazon is to prevent the bad effect of svi’ah, the ram levavcha, the shamanta avisa kasisa, the kochi ve’otzem yadi. Thus, there is no kal vachomer from Bracha Achrona that would obligate a Bracha Rishona, because the logic of Bracha Achrona does not apply at all to Bracha Rishona.
(I know I’m going to get complaints about this, but I say that Senator John Edwards said a very profound thing this week. After admitting that he had lied, and that he had indeed been unfaithful to his wife, Edwards said. "In the course of several campaigns, I started to believe that I was special and became increasingly egocentric and narcissistic.” He realized that ga’ava is the threshold of sin, and the feeling of satiety and confidence can blind people to the deadly consequences, both moral and personal, of infidelity. And what is infidelity other than denial of your obligation to others?)
Le’havdil, back to Reb Meir Simcha. The context of the mitzva of Birkas Hamazon supports his pshat. Immediately preceding the mitzvah of birkas hamazon, the Torah indicates that the miracle of the forty-year daily delivery of mahn in the desert served to highlight to the Jewish People the fact that "Man does not live by bread alone, but through the word of G-d, does Man live" (8:3) which (among other meanings) can be read as: it is not your efforts alone that bring about the bread, but, just as the mahn from the sky was clearly Divinely granted, so too bread from the ground is also Divinely granted through the mask of the natural order created by G-d. After the mitzvah to bless Hashem after eating, the Torah warns us: "v’rahm l’vavcha v’shahachta es Hashem... who has fed you mahn in the desert ... and you will say: “kochi v’otzem yadi asso li es hachayil hazeh...v’zacharto es Hashem Elokecha ki hu hanosein l’cha ko’ach laasos chayil.”(14-18).
The function of the birchas hatorah, on the other hand, as the Gemora in Nedorim 81 indicates (lo birchu batorah t’chiloh, as the Ran there and the Bach in OC 47 explain), is to prevent a person from learning lekanteir, as a kardom lachpor bo. This must be prevented before the person starts learning— so there is no problem of “lo birchu batorah techilla.” If a person begins his learning with this awareness, he will not come to the sin of l’kanteir or view the Torah as a science like other sciences or philosophies. In fact, R Chaim Volozhiner in Nefesh Hachayim 4:6-7 says that a person should stop occasionally during learning and contemplate the fact that he is learning the r’tzon Hashem and connecting to Hashem through his learning “ki hu uretzono echad.”
In order to better understand R Meir Simcha’s vort, we have to think about poshut pshat in the hava amina of the kal vachomer of the Gemora in Brochos. The Gemara says “if he is m’vareich when he is full, kal vachomer he should make a bracha when he is hungry.” What’s the kal vachomer? The teretz is that there are two concepts people tend to conflate in brachos, and those are birchas hoda’ah and birchas hashevach. Hoda’ah expresses gratitude for what we have received, while Shevach expresses recognition and appreciation of, and trust in, Hashem’s being the only One that provides sustenance. So the Gemara says that if after we are full and satisfied we make a bracha to express our recognition of Hashem as the sole provider of sustenance in the past and our faith that he will provide in the future, certainly we ought to do so when we are hungry and the food is in front of us. On this, as RMS explains, the Gemara says that the logic of the bracha is not just shevach, or hoda’ah; instead, it is to help us to deal with the problem that comes from having a full stomach-- to prevent us from forgetting about Hashem. As long as you are hungry, you are naturally receptive to hakaras hatov. The problem only begins when you are no longer hungry. This problems is what Birkas Hamazon addresses.
I feed a cat that was born under our porch eighteen years ago. (UPDATE: After around twenty years of roaming and dispatching countless sparrows, the cat passed away in January 2009.) The kids named it Saddle because of a black spot on its back against a white background. This extraordinarily venerable alley cat never comes into the house, and is very leery of human contact.
I have been feeding it for its entire life, and it gets whatever we don't eat, from week-old chicken to left-over roast. While it welcomes the occasional mouse or bird eaten with fur and feather, (or at least did when it was young enough to catch something,) it is a picky eater; it won't touch liver or cholent meat. That stuff he leaves for the raccoons and opossums who will, inevitably, consume him too. When he's hungry, he is the most loving animal; he rubs himself against my leg, he extends his front legs and bows, he comes over to me and meows. Once he's eaten, though, he's the classic alley cat-- distrustful, untouchable, and almost invisible. The point is, that as far as I can tell, this cat actually loves me-when he's hungry. As soon as he's full, he sees me as just another pest and nuisance. The idea of Birkas Hamazon is that we need to learn not be like my cat.
And you don't really need proof from my cat. Anyone that lends money knows that when you agree to lend, or when you hand over the money, the other person is so grateful, so effusive. Once the money has been deposited in the other guy's account, and certainly once he spends it, you suddenly don't exist, and you will see the borrower far less than you used to. He becomes scarce. This is not just because he's nervous about paying the loan back; it's also because his gratitude turns into resentment for the fact that he owes you the money.