[1] This is the third generation of Mishnaic sages, as I have mentioned. Yehoshua ben Perachyah was the teacher of Yeshu the Nazarene. It was in his days that the Karaite outlook began to take hold, on account of what befell the Sages in Yerushalayim at the hands of King Hyrcanus — he who is referred to in the words of the Sages ז"ל as "King Yannai," who was also the High Priest. He made a great banquet for all his ministers and servants, and the king sat at the table together with the Sages of Yisrael, who were called Perushim. When the king's heart was merry with wine, he said to them: "I am your student — if you see me straying from the proper path, rebuke me and restore me to the straight way, for it befits you to rebuke and it befits me to receive." The Sages answered him: "We are witnesses this very day that you are righteous and wholehearted in your ways, a faithful king and a pious High Priest." The king rejoiced at their words. Then one among them, a wicked and base man named Elazar, said: "If you truly love to receive rebuke — the crown of kingship is sufficient for you; set aside the crown of the priesthood for the descendants of Aharon, for your mother was taken captive in the days of Antiochus and she was thereby rendered a chalalah (disqualified from priestly lineage), and therefore it is not fitting for you to enter the Holy of Holies." The king grew exceedingly angry, and their joy turned to mourning. Yonatan, the chief of the Sadducees who was present there, said to the king that the Sages had instructed him to shame the king before the people and the ministers, and that they had therefore remained silent and said nothing to Elazar. Thereupon the king slew many of the Sages that very day, and Elazar the reviler was burned with fire. His companions counseled him to utterly disgrace, destroy, and kill the Sages, and so that he would have no need of their learning, to abandon the Oral Torah and conduct himself solely according to the Written Torah. He then expelled the Sages — among them Shimon ben Shatach, who was the king's father-in-law — and disputes multiplied in Yerushalayim, and much blood was shed among the people of Hashem, for the common people sided with the Sages, the Perushim. The king and his ministers stood against them, and through this the Rabbinic tradition was disrupted for a brief time; great effort was expended to maintain the Torah through careful deliberation, yet they strained and wearied and were unable to do so — until Shimon ben Shatach and his colleagues and disciples were brought back from Alexandria, and the Rabbinic tradition and the received transmission were restored to their former strength. Nevertheless, there remained among them individuals who had already taken deep root in the Karaite outlook, having cast off the Oral Torah from upon themselves. These, however, are not the sect of Tzadok and Baithos, for the Sadducees and the Baithosians are sectarians and heretics who deny the World to Come, and they are not among the Karaites.

[2] The Chaver already drew attention to this matter at the end of the third discourse of the Kuzari. For now, it suffices for us to know regarding this pair — Yehoshua ben Perachyah and Nittai of Arbel — that they belonged to the third generation, and that their teachings came to define and clarify the words of their teachers, Yosi ben Yoezer and Yosi ben Yochanan. For since Yosi ben Yoezer had said, with respect to the study of Torah, that one's "house should be a meeting place for the Sages," his student Yehoshua ben Perachyah came to add that it is not good for a person to learn from many Sages at once, lest their views differ and contradict one another, causing the student to become confused. The philosopher Seneca already noted that one who hears from many teachers is like the stomach that fills itself with different foods it cannot digest. Therefore Yehoshua ben Perachyah taught that when a person is in pursuit of wisdom, it is not fitting that he draw water from many different Sages and make his "house a meeting place" for them for the sake of his learning; rather, he ought to "make for himself a teacher" — that is, he should choose one Sage to be his master and learn directly from him. The language of making is deliberately chosen, to convey that even if a person does not consider a particular Sage entirely worthy of that role, he should nevertheless appoint him as his teacher, for one's learning when studying on his own does not compare to one's learning when studying from another. For a person — even the wisest of the wise — cannot perceive his own affairs as clearly as another can perceive them for him. It is for this reason that the philosophers stated in their moral teachings: even the wisest of kings stands in need of counsel.

[3] He said: "Acquire for yourself a friend" — so that he and his friend may review [their learning] with one another and his studies may become well-established. He used the language of acquisition in reference to a friend in order to convey that if the friend should require his assistance, he should provide him with his full needs and, as it were, "acquire" him through bread — for the friend will engage with him in discussion of what he has learned, and they will sharpen one another. As our Sages, of blessed memory, said (Eruvin 54a): "For they are life to those who find them" (Mishlei 4:22) — do not read it as lemotz'eihem ("to those who find them"), but rather as lemotzi'eihem ("to those who bring them forth with their mouths") — for then the words are alive and enduring; but if one does not give voice to them orally, they will be forgotten, as if dead.

[4] The Sages have already offered profound reasons for the necessity of a teacher who instructs, since a person cannot arrive at full knowledge through his own inquiry alone unless he is aided and assisted by what his teacher has already investigated, studied, and transmitted to him. The matter is analogous to the making of bread: if a single farmer were required to plow, sow, harvest, grind, knead, and bake the loaf — as well as perform all the other labors that bread requires — the work would overwhelm him. He therefore needs helpers, each assisting in his own craft, so that one aids another. So too it is with a teacher, who assists the student with what he knows. One who refuses to listen to his teacher and will not receive from him will fall into the trap of foolishness, as happened to Yiftach and Pinchas in the matter of the vow he made, as recorded in Midrash Tanchuma. Our Sages, of blessed memory, said (Berachot 8a): "As long as Shimi ben Gera was alive, Shlomo did not marry the daughter of Pharaoh." And in the Jerusalem Talmud, the comment on this is: "Any Torah that has no father is not Torah." And in the Midrash it is said that "one who learns Torah from his own mouth" is not comparable to one who learns it from another. One who learns from another — his learning endures, what was obscure is revealed to him, and he is freed from doubt. One who learns on his own — his learning does not endure, his heart misgives him, it becomes forgotten, and doubts multiply upon him. By "his learning endures" they meant that his knowledge is preserved, since he trusts that it is true on account of having received it from his teacher. But one who learns on his own is not confident in his own understanding, and therefore his learning is unstable and becomes forgotten. Likewise, having a study companion is indispensable and inescapable. For a person is ashamed to engage with his teacher in detailed discussion over every particular he hears from him, and so he is left with many doubts and uncertainties; but if he has a companion, they can engage in give-and-take with one another and both will be sharper for it. It is stated in the first chapter of Bava Batra (Bava Batra 16b): "Either companionship or death" — for it is not good for a person to be alone. It is in this spirit that Shlomo said (Mishlei 15:30): "Oil and incense gladden the heart, and the sweetness of one's friend is better than one's own counsel." That is to say: just as compounded oil and fragrant incense, though external things, gladden a person's heart, so too the sweetness received from a friend surpasses one's own counsel — meaning, the counsel one gives to oneself.

[5] This honorable moral teaching thus encompasses the principle that a person should choose and appoint for himself a single teacher who will instruct him. For although Ben Zoma said, "Who is wise? One who learns from every person" (Avot 4:1), his intent is not that one should learn and receive from all people simultaneously, but rather that one should learn from each person in turn, or from each person in his particular area of expertise. For example, one should learn Torah from either Hillel or Shammai — but not from both of them together. And one should learn natural philosophy from Aristotle and the science of astronomy from Ptolemy, were they all available to him — but in any single discipline, one should not make for himself more than one teacher and one companion. And many proofs of this principle may be found throughout the Talmud and the Baraitot. The philosophers, too, said: a person without a companion is like a left hand without a right. They likewise said: the finest of horses still requires a bridle; the most virtuous of women still requires a husband; and the most discerning of men still requires a friend's counsel. And one wise man said to his son: "Let not a single enemy seem insignificant in your eyes, and let not a thousand wise men seem too many."

[6] After this, the mishnah teaches: "Judge every person favorably." This may seem unrelated to what precedes it, but its reason is as follows: when one has chosen a particular rabbi and a particular companion with whom to engage in Torah discussion, he should not cast aspersions upon other rabbis or upon other companions, for he should judge them all favorably — regarding them, in his own eyes, as innocent and righteous. As our Sages, of blessed memory, taught (Shabbat 127a): "There are six things whose fruits a person enjoys in this world while the principal remains for him in the World to Come, and they are: hospitality to guests, visiting the sick, devotion in prayer, rising early to attend the house of study, raising one's children to Torah study, and judging one's fellow favorably." Here they placed "judging one's fellow favorably" alongside Torah study, for the very reason I have mentioned. The root of this moral teaching is already found in the Torah itself: the Holy One, blessed is He, gave Yisrael only one rav — Moshe Rabbeinu, peace be upon him — and when He gave Moshe a companion in his mission and in the receiving of the mitzvot, He gave him only one companion, Aharon his brother. It was for this reason that the transmission of the Torah was entrusted to Yehoshua, and from him to the elders — and even though in every generation there were many wise men, there was always a single head of the court, known as the Nasi or Shofet, and a single companion, known as the Av Beit Din. It follows, then, that Yehoshua ben Perachyah also came to elaborate upon the teaching of Shimon HaTzaddik regarding the Torah. The Rambam, in his commentary, has already cited the many virtues of judging a person favorably, noting that this applies when the person is known to be pious and upright, or when his character is unknown — whether he is righteous and honest or not. However, if he is known to be a wicked and base individual, it is not appropriate to judge him favorably, as it is written (Mishlei 26:25): "Though he makes his voice gracious, do not trust him." Regarding this, it is likewise stated: "He who says to the wicked, 'You are righteous' — peoples shall curse him, nations shall denounce him" (ibid. 24:24).