The Obligation to Study Torah
Most mitzvos have clearly defined parameters. By placing a mezuzah on one’s doorposts, or eating a k’zayis of matza on Seder night, one fulfills his obligation, and nothing more must be done. This is not true of the mitzva of Torah study, which requires us to constantly pursue the wisdom of Hashem. What then are the parameters of this mitzva? What is required, and what is merely praise-worthy, and at what point can a person say that he has fulfilled his obligation to study Torah?
Day and night
When Hashem first revealed Himself to Yehoshua ben Nun, instructing him to accept the mantle of leadership after Moshe’s passing, He placed upon him a weighty charge, incumbent on himself, and upon all of Klal Yisroel, for all generations to come:
לא ימוש ספר התורה הזה מפיך והגית בו יומם ולילה למען תשמר לעשות ככל הכתוב בו כי אז תצליח את דרכך ואז תשכיל.
This Sefer Torah shall never leave your mouth, and you shall contemplate it day and night, in order that you may observe all that is written in it. Then you will achieve success and wisdom.
From here, our Sages learn that we are commanded to study Torah every day and night. However, according to R’ Shimon, even if one does no more than recite Shema every morning and night, he fulfills this obligation, since Shema is composed of pesukim from the Torah. (The Gemara warns against revealing this to an am ha’aretz – ignoramus, lest he rely on it entirely, and refrain from studying anything more.)
The Ran explains that although reciting Shema is enough to fulfill the commandment of והגית בו יומם ולילה – “You shall contemplate it day and night,” it is not enough to fulfill the obligation expressed in the possuk, ושננתם לבניך - “And you shall teach them thoroughly to your children,” from which our Sages learn that we must toil in Torah study until we become thoroughly proficient in it.
Nevertheless, in his halachic compendium, the Rema rules that: “In difficult times, if one only recites Shema morning and night, he fulfills his obligation.” The Vilna Gaon notes that this ruling contradicts the Ran, who explains that by reciting Shema, one may fulfill his obligation of, “You shall contemplate it day and night,”, but he does not fulfill his obligation of “You shall teach them thoroughly.”
Two different aspects of Torah
Perhaps we can explain that the Rema does not contradict the Ran at all, since each one addresses a different aspect of Torah study. The Rema deals with the obligation to set fixed times each day to study Torah, each person according to his abilities and his time restraints. In this regard, the Rema writes that when difficulties arise, and one cannot study any more, if he at least recites Shema, he fulfills his obligation to study Torah every day and night.
The Ran, however, addresses the obligation to advance in Torah wisdom, and becomes thoroughly proficient in one’s studies. This is not a specific obligation for a particular day or night, like eating matza on Pesach or lighting candles on Chanukah, of which we may ask, “How much matza must one eat? How many candles must he light?” Here, we cannot ask, “How much Torah must I study tonight?” since it is anyway impossible to master the Torah in one night. Rather, becoming proficient in Torah wisdom is a long term goal, towards which we must all strive over the course of our lives.
A life-long goal
In fact, it is perhaps inaccurate to define the quest for Torah proficiency as a mitzva, since the simple meaning of ושננתם לבניך is that we must teach Torah to our children. Our Sages understood from the usage of the word, ושננתם, that we must teach Torah in such a way that we and our children understand it clearly. (The word ושננתם can also mean “sharp,” which in this context implies, “clearly defined” or “well understood.”) Since this is not a daily mitzva, but rather a life-long goal, one would not have to study at all on any given night – if not for the parallel mitzva of, “You shall contemplate it day and night,” (which, if necessary, one can fulfill by reciting Shema).
In any case, the experience of three thousand years has proven that the only path to Torah greatness is by treasuring every precious moment, and devoting all our time, night and day, to the pursuit of Hashem’s wisdom. Throughout the generations, this was the path followed by our Torah leaders, and their students after them, in the yeshivos they founded in all the communities of Klal Yisroel.
Interrupting Torah Study
to Read the Megillah
The Gemara instructs us to “interrupt Torah study in order to read the Megillah,” and elsewhere, to “interrupt Torah study to recite Shema.” Since Megillas Esther is one of the 24 Books of Tanach, and Shema is composed of verses from the Torah, it seems odd that our Sages viewed them as interruptions of our study.
Perhaps our Sages did not refer to the time spent hearing the Megillah read. Rather, they referred to the time spent taking out the Megillah scroll, going to shul, waiting for it to be read, etc. This explanation is supported by the wording of the Gemara:
מכאן סמכו של בית רבי שמבטלין תלמוד תורה ובאין לשמוע מקרא מגילה.
The household of Rebbe (Yehuda HaNassi) relied on this, to interrupt their Torah study, in order to come and hear the Megillah read.
The Gemara adds the word “come”, to stress that the only interruption in their study was coming to shul, whereas the actual reading of the Megillah was not considered an interruption. However, this is insufficient to explain why Shema is considered an interruption, since it need not be read in shul, or from a special scroll. The question thus remains, why are these things considered bitul Torah? Instead, the following explanation seems more likely.
Torah as prayer
As we know, birkos HaTorah must be recited before studying Torah. The Poskim debate whether or not one may recite pesukim from the Torah as part of davening, even before reciting birkos HaTorah. In essence, they debate whether words of Torah recited in a context other than Torah study per se are considered a fulfillment of this mitzva, thus warranting a beracha, or not. According to the opinion that verses recited as part of davening do not fulfill the mitzva of Torah study, and thus do not warrant a beracha, it is well understood why hearing the Megillah and reciting Shema are considered interruptions of Torah study.
However, according to the other opinion (which the Mishnah Berurah accepts), that birkos HaTorah must be recited before saying pesukim during davening, it seems that regardless of the context in which they are said – words of Torah are always considered Torah study. As such, the question remains – why are Megillah and Shema considered bitul Torah?
Need one understand his studies?
The Poskim further debate if the mitzva of Torah study is fulfilled by reciting words of Torah, if one does not understand their meaning. According to the Magen Avraham, if one does not understand what he says, it is not considered Torah study at all. The Maharal of Prague argues that even if one does not understand, he still fulfills the mitzva of Torah study. The Shulchan Aruch HaRav presents a compromise: when reading a Book of Tanach, one fulfills the mitzva of Torah study, even if he understands nothing at all. When studying the Oral Tradition of Torah, such as Mishna, Gemara, and the like, he fulfills a mitzva only if he understands what he learns.
Clearly, the reason for this distinction is that the very words of the Written Torah were specifically chosen by HaKadosh Baruch Hu – each letter containing an infinite wealth of sublime wisdom, far beyond our ability to fathom. Simply by reading these letters, and uttering the words spoken by Hashem, one binds himself to He Who spoke them. However, this is not true of the Oral Torah, which was not delivered in any specific wording. Its profundity lies not in the words of the Mishna or Gemara, but in the concepts they convey. Therefore, if one does not understand these concepts, it is not considered Torah study.
The pursuit of wisdom
Even if we were to grant that reciting words of Torah without understanding them is considered a fulfillment of the mitzva to study Torah, this is not the highest level of Torah study. The pursuit of wisdom is like a ladder that we must climb, one rung after another, to reach ever higher levels of closeness to Hashem, by grasping His wisdom to the greatest degree possible. As such, we find in the Gemara: “If a person studies only the Written Torah, his measure is incomplete. If he studies Mishna, his measure is complete, and he will be rewarded for it. If he studies Gemara, there is no greater measure.”
The implication here is that the main mitzva of Torah study, is to come to a complete understanding of the laws and ways of the Torah, as our Sages learn from the word, ושננתם, that we must teach Torah in a way that we and our children understand it clearly. Furthermore, the true greatness of Torah lies in its ability to inspire us to proper behavior. The more we understand the Torah, the more it guides us to improve our behavior.
We can now understand, that even if Megillah and Shema fulfill the mitzva of Torah study on some level, they do not represent the highest level of Torah study, since our focus is to publicize the miracle of Purim, or accept Hashem’s Kingship – but not to understand the depth of wisdom inherent in these pesukim. Therefore, our Sages referred to them as interruptions in the mitzva of Torah study – in quality, if not in quantity.
The Goal of Torah Study
Maintaining a keen mind for Torah
The Taz writes as follows:
שיש תלמידי חכמים שמנדדין שינה מעיניהם ועוסקין בתורה הרבה, ויש תלמידי חכמים שישנים הרבה כדי שיהיה להם כח החזק וזריזות לב לעסוק בתורה הרבה, ובאמת יכול ללמוד בשעה אחת מה שזה מצטער ועוסק בשני שעות. ובודאי שניהם יש להם שכר בשוה, על כן אמר "שוא לכם משכימי קום" דהיינו בחנם לכם שאתם מצטערים ומשכימים בבוקר מאחרי שבת בלילה וממעטים שנתם, זה בחנם כי "יתן ה' לידידו שנה" דהיינו מי שישן הרבה כדי שיחזק כוחו בתורה נותן לו הקב"ה חלקו בתורה כמו אותו שממעט בשינה ומצער עצמו כי הכל הולך אחר המחשבה.
Some Torah scholars brush sleep from their eyes to devote extra hours to their studies. Other Torah scholars sleep sufficiently, to have the strength and mental agility to study well. [Since they are well rested], they can learn in one hour what their sleep-deprived peers would learn in two.
Since both receive equal reward, the possuk warns us, “In vain do you rise early.” There is no benefit in depriving yourself of the necessary rest, by going to sleep late, and waking up early. “Hashem gives rest to His beloved”, meaning, HaKadosh Baruch Hu gives an equal portion of Torah to he who sleeps sufficiently to have strength to learn Torah, and he who suffers the deprivation of sleep. In the end, everything depends on one’s purity of intent.
One might argue that since every moment spent in Torah study is a mitzva unto itself, why does the Taz take for granted the quantity of Torah should be sacrificed for the sake of quality? Albeit both scholars achieve the same amount of wisdom, but the one who deprives himself is perhaps superior, since he spends more time learning – and thus has more mitzvos of Torah study to his credit.
Nonetheless, the Taz’s conclusion is well-founded, since this argument can be refuted in two ways. Firstly, the mitzva of Torah study obligates us to dedicate every free moment to Torah. It does not obligate us to forsake our basic bodily needs, such as the sleep we need to maintain our mental and physical health. Necessary sleep is in no way considered bitul Torah.
Secondly, according to the Ran cited above, the obligation to dedicate all our free time to Torah is learned from the possuk, ושננתם לבניך, “You shall teach them thoroughly to your children,” from which our Sages learn that we must make the Torah “sharp”, i.e., clearly defined, upon our tongues. As such, Torah must be studied in the conditions best suited to achieving clarity of thought. Therefore, it is no wonder that the Taz favored sacrificing quantity of time spent in Torah study for the sake of quality, since the ultimate goal is to achieve clarity.
The best way to learn
The Arugos HaBosem was once asked whether it is better to learn Torah at night before going to sleep, or to wake up early to learn. On one hand, the principle of zrizin makdimin l’mitzvos (the zealous hasten to perform mitzvos) would counsel us to learn Torah before we go to sleep, rather than waiting for the next morning. On the other hand, the principle of mitzva min hamuvchar (performing mitzvos in the best possible way) would counsel us to learn before sunrise, which is the most ideal time for Torah study. The Arugos HaBosem wrote a lengthy treatise, in which he weighs one principle against the other, trying to determine which takes precedence.
However, in my opinion it seems clear, that there can be no set rules in this matter. Each person has his own abilities, his own schedule, and his own situation, and must decide what is best for himself to reach the objective of becoming proficient in Torah.
The Merit of Developing New Torah Ideas
Two mitzvos or one?
Acharonim such as the Shulchan Aruch HaRav and R’ Yisrael Salanter zt”l distinguish between the mitzva to study Torah, and the mitzva to know the Torah. However, none of the Rishonim who number the 613 mitzvos list these as two separate mitzvos. Rather, it seems that they are not really two different mitzvos, per se, but two distinct aspects of the same mitzva. That is to say, the mitzva of Talmud Torah is to learn Torah in order to know it, as the possuk seems to imply, ולמדתם אותם ושמרתם לעשותם - “And you shall study them, to observe and perform them.”
With this we can explain an interesting incident, in which the captain of the angelic hosts appeared to Yehoshua during his siege of Yericho, to berate him for his negligence in Torah study at night. Yehoshua made amends for his mistake by spending the next night, together with all the Jewish soldiers, in deep discussion of halachic matters. 
Since every night has its own mitzva of Torah study, how did Yehoshua’s Torah study the following night amend for his failure to study on the night before? Perhaps we can explain, that since the ultimate goal of Torah study is to achieve proficiency in Torah wisdom, and thus quality of study is more important than quantity, Yehoshua made amends by delving so deeply into Torah study on the following night, that he compensated for the wisdom that had been lost the night before.
Furthermore, exhausted by the strain of battle during the day, the Jewish soldiers were most likely exempt from concentrating on deep Torah matters at night. It would have been enough for them to have studied superficially, as appropriate to the constraints of their situation. Yet, they went beyond their obligations, forcing themselves to focus on complicated studies on the second night, and thereby atone for their failure to study Torah at all on the previous night.
Another insight into Yehoshua’s decision to lead his soldiers into the fray of complicated Talmudic debate, can be gained from the following passage from Tanna D’Vei Eliyahu:
אשרי מי שמתחדש דברי תורה על פיו ... ארבעים אלפים מישראל שנתקבצו יחד ויצאו למלחמה ויש ביניהם זוג אחר תלמידי חכמים דומה להם כאלו אחזו מגן ותריס וחרב פיפיות בידם לכך נאמר "מגן אם יראה ורומח בארבעים אלף בישראל."
Fortunate is he who develops novel Torah concepts … If forty thousand Jewish soldiers gather to go out to war, and among them is a pair of Torah scholars, it is as if they held shields and two-edged swords in their hands.
Learning Torah in depth, and developing novel Torah concepts, is a great merit for Bnei Yisroel, to protect us from misfortune, and grant us success in battle and in all our endeavors.
 Yehoshua 1:8
 Menachos 99b
 Nedarim 8a
 Devarim 6:7
 Kiddushin 30a
 Yoreh Dei’ah 246:1
 ibid, s.k. 6
 Megillah 3a
 Shabbos 11a
 See Teshuvos Beis Efraim: Orach Chaim 68; Teshuvos Avnei Nezer: Orach Chaim II 517. Mahara”l Diskin explained that since we do not know the meaning of the words האחשתרנים בני הרמכים from the Megillah (see Megillah 18a), these words alone are considered “bitul Torah,” whereas the rest of the Megillah is not. However, the other Poskim who posed the question above, seemed to interpret the Gemara at face value, that the entire Megillah is considered an interruption to our studies.
 See Shulchan Aruch: Orach Chaim 46:9
 50 s.k. 2
 Gevuros Hashem, ch. 47
 Laws of Talmud Torah, 2:12
 Bava Metzia 33a
 Kiddushin 40b
 A further proof for this conclusion can be found in the Rashba’s explanation of the Gemara, which states, “Reciting Shema in its proper time is more important than Torah study” (Berachos 10a). The Rashba asks why is this considered “greater than Torah study,” when in fact it is Torah study itself, since the parshiyos of Shema are parts of the Torah? He explains that the mitzva of Krias Shema in its proper time takes precedence to delving into the depths of Talmudic thought, although the latter is a higher form of Torah study.
 Taz, Even Ha’Ezer 25 s.k. 1
 Teshuvos, Orach Chaim 1
 Devarim 5:1
 Megillah 3a; Sanhedrin 97b