The mishnah before us is mishnah 15 in chapter 5 (in some editions it is numbered mishnah 18), and it is the last of the mishnayos built around numbered lists. After the tens and the sevens, we arrived at the fours, and this is the last of them. From here on the chapter continues with other matters, in mishnayos of the ordinary style. And since the tractate contains only five chapters, we are drawing near to its conclusion, even though the sixth chapter still lies ahead of us, the chapter of 'Kinyan Torah', which we will discuss later.
A few mishnayos ago we discussed two qualities in students, two dimensions: intelligence, the ability to learn quickly and grasp things, and memory, the ability to retain what was learned. But there is a third dimension in a student: the power of discernment. This is the ability to decide and to distinguish between the essential and the peripheral, between the important and the unimportant, between truth and falsehood, between what is correct and what is not. This ability serves as a bridge between the other two dimensions: a person may learn very well, but what should he remember? What deserves to be stored in his memory?
That critical faculty is what separates the wise man from what Chazal called 'a donkey carrying books', a donkey with a pile of books loaded on its back. In the language of Chazal elsewhere: there is one who is 'gamir v'lo savir' and one who is 'gamir v'savir'. 'Gamir' means that he has learned, that the information is in his possession; but is he 'savir'? Has he processed the material and thought it through to the end? Does he have an opinion? Does he understand what is essential and how things work, or does he simply know a great many facts, like a champion at a trivia contest, without penetrating to the depth of how things operate, and without distinguishing between essential principles and exceptions, between general rules and details?
The mishnah compares four types of people, according to their power of discernment, to four vessels. First we need to understand what each of these vessels is:
Sponge (sfog) - it absorbs everything, clean water and murky water alike. It takes in whatever there is and holds it inside.
Funnel (mashpech) - a vessel used for transferring. When one wishes to move wine from a wide mouthed barrel into a narrow bottle, one places a funnel in between: its upper opening is wide and its lower opening is narrow, and everything that enters it comes out of it. Nothing is retained in it and nothing is lost, everything simply passes through.
Strainer (meshameres) - a filtering vessel, a kind of cloth used for separating. It is placed over the mouth of the barrel when pouring from barrel to barrel, in order to catch the dregs and the sediment that have settled at the bottom, the waste that one does not want in the wine. The strainer holds the waste inside it, while the good part passes through its holes into the vessel below.
Sifter (nafah) - in the process of preparing flour one wants to be rid of the fine particles of dust that are not fine flour. In a sifting vessel the good part stays inside, while the waste falls through the holes.
Explanation of the mishnah:
"Sfog - shehu sofeg es hakol" - he takes in everything and retains everything. His head may be disorganized, but it is full of material, and that is a virtue. Such a person is 'gamir v'lo savir': he has learned, but he has not yet processed the information or thought it through to the end.
Here is an analogy: a museum containing a million items, and its guide is a sponge. That guide can tell me all million details. If I tell him that I have only one day, he will begin with the first item, move on to the second and the third, until the time runs out. The one with discernment, by contrast, will say: "You only have one day? Well then, there are seven items here that you must see", and he knows exactly why those particular items matter. The sponge has everything stored in his head, but he does not understand what is truly important and what is not.
"Mashpech - shemachnis b'zo umotzi b'zo" - in one ear and out the other, and quite literally: it enters through one opening and exits through the other. Such a person learns and remembers nothing, and consequently it makes no difference whether he understood or not, since he has neither discernment nor retention. He is 'lo gamir v'lo savir'.
"Meshameres - shemotzi es hayayin v'koletes es hashemarim" - the Meiri writes that this trait is worse even than the funnel, since such a person retains precisely the bad material. This is the person who remembers every joke and every crude and unworthy detail, like those who say: "I do not speak that foreign language, but I know all its curse words". He loses the wine and takes in the sediment at the bottom. His inferiority lies in the fact that he is full of nonsense, and directs his power of discernment specifically toward bad things. Such a person, sadly, is a jester.
The Meiri notes that most people are like this: they remember what is unimportant and lose what is important. This person too is 'lo gamir v'lo savir': he did not remember what was worth remembering, and he certainly did not process the good material.
"Nafah - shemotzi es hakemach v'koletes es hasoles" - it rids itself of the bad and keeps all the good: it removes the inferior part of the flour and retains the quality flour. Such a person is 'gamir v'savir': he has learned, he has processed the information and understood it properly, and he has thought things through to the end. This is a person of whom you can ask any question and he has an opinion on it. Not only does he know things, he knows what is important and he knows how things work.
In practice:
In Choshen Mishpat (paragraph 3) the Shulchan Aruch discusses whether a person is fit to sit in judgment as one of three. Someone who is like a sponge, even though he is "gamir velo savir" - he has learned but does not reason - may sit on a court of three, since the facts are known to him; between the three of them they will examine the matter and arrive at the truth. In contrast, the one who resembles a funnel, and all the more so the one who resembles a strainer that retains the bad, is "lo gamir velo savir" - he has neither learned nor reasoned - and he cannot serve as a judge at all.
But the one who resembles a sieve, who has processed what he learned and is "gamir vesavir" - he has learned and he reasons, he has thought things through in depth, he has a method, and he understands how things work and why - he is the type of person who can be considered an expert, who judges alone. For it is possible for a person to sit as a judge by himself, without a court of three, if he has been recognized as an expert. And the expert is the one who possesses discernment. This is what separates the wise man from a "donkey carrying books."
In summary: The Mishnah presents four types according to their capacity for discernment: the sponge that absorbs everything, the funnel that loses everything, the strainer that keeps the dregs and lets the wine escape, and the sieve that keeps the fine flour and lets out the coarse flour. The level of the sieve, the one who is "gamir vesavir," is the goal to strive for, and it even finds expression in practical halachah. True, the critical faculty is to some degree inborn, but to a great degree it is a matter of learning: to think things through to the end, to take care to preserve the good information, to discard falsehood and whatever is unimportant, and in this way to acquire a method and an opinion and to understand how things work - until a person is both "gamir" and "savir."