Besides an acquaintance with tradition, he seems to have possessed some astronomical knowledge, which enabled him to calculate the irregular course of the comets. This knowledge was once of great use to him when he was on a journey. He had started on a voyage with Gamaliel, and had laid in more provisions than were usually necessary for the journey. The ship took an erratic course for some time, because its captain, deceived by the sight of a certain star, had steered in a wrong direction. Gamaliel's provisions having been consumed, he was astonished that this was not the case with his companion, but that, in fact, he could even spare some for him. Thereupon Joshua informed him that he had calculated on the return of a star (a comet), which reappeared every seventy years, and which would mislead the ignorant sailor, and that therefore he (Joshua) had provided himself with extra food for this emergency. This astronomical knowledge of Joshua appears the more surprising, as the cycles of the comets were known not even to the learned of antiquity. But Joshua was yet more distinguished for his modesty and gentleness than for knowledge and wisdom, and these qualities he displayed also in teaching. He was opposed to all exaggeration and eccentricity, and gave heed to the circumstances of daily life when making a legal decision.

Joshua warmly expressed his disapproval of the numerous measures which the school of Shammai had introduced before the destruction of the Temple, under the name of "the eighteen rules," and which rendered impossible all closer relations or friendly communications with the heathens. He said, "On that day, the school of Shammai went beyond all bounds in their decisions; they behaved as one who pours water into a vessel containing oil; the more water one pours in, the more oil runs off," which meant that, by introducing a number of superfluous details, the really important things were lost. Joshua seems also to have opposed the unmeasured deductions of the Hillelite school. He said that the regulations respecting the Sabbath, festive offerings, and misuse of holy things, have but slight foundation in Holy Writ, but have many Halachas in their support.

The balanced and calm character of Joshua rendered him especially fitted for the part of intermediary between the Jewish nation and Roman intolerance. He was the only teacher who sought and enjoyed the confidence of the Roman rulers; without betraying his trust to the Romans, he yet persuaded the opposing forces to be mutually more yielding. The death of Gamaliel, and the hostile attitude of the Jews towards the Romans during the last years of the Emperor Trajan and the early years of Hadrian's reign, seem to have torn Joshua away from his petty trade, and to have put the public leadership into his hands. It is not improbable that he assumed the patriarchal position; at least the circumstance that he removed the ban from Eliezer after the latter's death, an act which could be performed only by a patriarch, or one equal in authority, affords some ground for this supposition. Joshua's activity during the last years of his life forms an important part of the history of his times.

Amongst the personages of this period, Akiba ben Joseph was unquestionably the most talented, original and influential. His youthful days and mental development are shrouded in darkness, as is often the case with characters who leave their mark in history; but legends have cast sufficient light to show the obscurity of his descent. According to one legend, he was a proselyte, and a descendant of Sisera, who fell through a woman's deceit. Another legend represents him as a servant of Kalba-Sabua, one of the three richest men of Jerusalem, who, by their provisions, wished to prevent for many years the famine occasioned by the siege. The legend adds that the daughter of one of these wealthy men of Jerusalem, named Rachel, had bestowed her love on Akiba, on the condition that he should follow the study of the Law. In those days this meant to acquire culture, and thus, in his fortieth year, Akiba entered a school, in order to take his first lessons to obtain the knowledge in which he was deficient. During the period of his studies the daughter of Kalba-Sabua had remained faithful to him, living in the greatest poverty, to which her father in his anger had reduced her by casting her adrift. Of these stories so much is certain, that Akiba was very ignorant until he was well advanced in years, that he and his wife lived under very straitened circumstances, and he related later on that during the period of his ignorance, he hated those who were versed in the Law.

Meanwhile his slumbering mind did not develop so quickly as the legend relates. One source declares that he was one of the pupils of Eliezer during many years, without ever showing himself worthy of receiving an instructive reply from him. His teacher appears to have regarded him with a certain amount of contempt. Perhaps the peculiar system, pursued by Rabbi Akiba with regard to the newer Halachas, also excited Eliezer's disapproval. Akiba had learned this new system under Nachum of Gimso (or Emmaus), under whom he studied, not, indeed, for two-and-twenty years, as the legend relates. Akiba raised what was incomplete and fragmentary in this school to a complete system, and thus he stands at a turning-point in Jewish history.

The peculiar system of Akiba was built on certain principles, and in fact he may be considered as the only systematic Tanai. In this system the law was not considered as a dead treasure incapable of growth or development, or, as it was in the eyes of Eliezer, a wealth of mere memories, but it formed an everlasting quarry in which, with proper means, new treasures might always be found. New laws were also no longer to be formulated by the voice of a majority, but were to be justified by and founded on the written documents of the Holy Word. As the fundamental doctrine of his system, Akiba maintained that the style of the Torah, especially in parts relating to the laws (Halachas), was quite different from that of other writings. Human language, besides the indispensable words employed, requires certain expressions, figures of speech, repetitions, and enlargements—in fact it takes a certain form which is almost unnecessary for conveying the writer's meaning, but which is used as a matter of taste, in order to round off the sentences and to make them more finished and artistic. In the language of the Torah, on the other hand, no weight is put on the form; nothing is superfluous, no word, no syllable, not even a letter; every peculiarity of expression, every additional word, every sign is to be regarded as of great importance, as a hint of a deeper meaning that lies buried within. Akiba added a number of explanatory and deductive rules to those of Hillel and Nachum, and his additions afforded fresh means of development for the traditional law. When a deduction had been obtained by the correct use of the rules, such conclusion might again be employed as the foundation for fresh deductions, and so on, in a continuous chain.

Akiba was not to be restrained in this course by any consequences whatsoever. He had opened up a new path with his system, and a new point of view. The Oral Law, of which it had been said that it hung on a hair and had no firm ground in Holy Writ, was thus placed on a firmer basis, and the dissensions concerning the Halachas were to a considerable degree diminished. Akiba's contemporaries were surprised, dazzled, and inspired by his theories, which were new and yet old. Tarphon, who had at one time been the superior of Akiba, said to him, "He who departs from thee departs from life eternal; for what has been forgotten in the handing down, that dost thou give afresh in thy explanations." It was acknowledged that the Law would have been forgotten or neglected, had not Akiba given it his support. With exaggerated enthusiasm, it was said that many enactments of law, which were unknown to Moses, were revealed to Akiba.

Just as Akiba had recognized and confirmed the worth of the traditional law, he also assisted in reducing it to a methodical system and order. He laid the foundation for the possible collection of the rich material at hand. It has already been stated that the Halachas were strung together without connection or systematic grouping; it was therefore necessary, in order to retain the entire mass, to maintain years of intimacy with those who were acquainted with the Halachas, to be untiringly industrious, and to have a faithful memory. Akiba, however, facilitated the study of the Halachas by arranging them in groups, and thus assisted the memory. The arranging of the Halachas he carried out in two ways. He put them together according to their context, so that all Halachas concerning the Sabbath, marriage laws, divorces, and property should form independent wholes. Thus the entire matter was divided into six similar parts, each part bearing the name Masechta (Textus—Division). These divisions he arranged according to numbers, so as to give a useful aid to the memory; thus, from four causes injuries to property might occur; five classes of men could be excluded from the tithes of the priests; fifteen classes of women were prevented by consanguinity from intermarrying with their brothers-in-law; thirty-six kinds of sins are recorded in the Holy Writings as being punished by extermination. The collection of the Halachas, instituted by Akiba, was called the Mishna, or more fully Mishna of Rabbi Akiba, to distinguish it from the later collection; in Christian circles it was known under the name of Akiba's Deuterosis. It was also called Midoth (Measures), probably on account of the numbers which form the basis of arrangement. This Mishna or Midoth, though arranged, was not written down; the contents remained as before traditional, but an easier method was employed in classifying them. It is hardly probable that Akiba alone completed and arranged all this material. His pupils no doubt assisted in this collection which, later on, formed the foundation of the code that terminated the whole traditional system.

The older Mishnas (Mishna Rishona) were often separated from the later (Mishna Acharona, or Mishna of Rabbi Akiba), and the latter were taken as the norm. The name of the new founder of the Oral Law became, through his peculiar mode of teaching, one of the most celebrated in the Jewish communities far and wide. His mysterious descent and his lowly origin only heightened the interest felt in him. The number of his hearers is exaggerated by tradition, which fixes it at twelve thousand, and even double that number, but a more modest record represents them as amounting to three hundred. Accompanied by this numerous band of disciples, Akiba again visited his wife Rachel, who for some years had lived apart from him in the greatest poverty. The scene of their meeting is touchingly described, and her hard-hearted father, Kalba-Sabua, proud of such a son-in-law, is said to have bequeathed to him his whole property. From this time Akiba lived in great riches with his wife, who had previously been so poor that she slept on a bed of straw. His gratitude to his sorely tried wife was in proportion to the sacrifices which she had made for him.

Akiba had his fixed domicile in Bene-Berak, where his school was situated. The position of this spot, which, through him, became so celebrated, is supposed to be southeast of Joppa. Others place it yet more to the south, near Ashdod; but Akiba was a member of the Synhedrion in Jabne, and it was but seldom that any measure was determined without him.