Three words of modern significance, with which of late we have all become too familiar, will probably better help us to understand the whole state of matters than more elaborate explanations. They are connected with that ecclesiastical system which in so many respects seems the counterpart of Rabbinism. Ultramontanism is a direction of religious thought; the Ultramontanes are a party; and the Jesuits not only its fullest embodiment, but an "order," which, originating in a revival of the spirit of the Papacy, gave rise to the Ultramontanes as a party, and, in the wider diffusion of their principles, to Ultramontanism as a tendency. Now, all this applies equally to the Pharisees and to Pharisaism. To make the analogy complete, the order of the Jesuits also consists of four degrees  -- curiously enough, the exact number of those in the fraternity of "the Pharisees!"
Like that of the Jesuits, the order of the Pharisees originated in a period of great religious reaction. They themselves delighted in tracing their history up to the time of Ezra, and there may have been substantial, though not literal truth in their claim. For we read in Ezra 6:21, 9:1, 10:11 and Nehemiah 9:2 of the "Nivdalim," or those who had "separated" themselves "from the filthiness of the heathen"; while in Nehemiah 10:29 we find, that they entered into a "solemn league and covenant," with definite vows and obligations. Now, it is quite true that the Aramaean word "Perishuth" also means "separation," and that the "Perushim," or Pharisees, of the Mishnah are, so far as the meaning of the term is concerned, "the separated," or the "Nivdalim" of their period. But although they could thus, not only linguistically but historically, trace their origin to those who had "separated" themselves at the time of Ezra and Nehemiah, they were not their successors in spirit; and the difference between the designations "Nivdalim" and "Perushim" marks also the widest possible internal difference, albeit it may have been gradually brought about in the course of historical development. All this will become immediately more plain.
At the time of Ezra, as already noted, there was a great religious revival among those who had returned to the land of their fathers. The profession which had of old only characterised individuals in Israel (Psa 30:4, 31:23, 37:28) was now taken up by the covenanted people as a whole: they became the "Chasidim" or "pious" (rendered in the Authorised Version, "saints"). As "Chasidim," they resolved to be "Nivdalim," or "separated from all filthiness of heathenism" around. The one represented, so to speak, the positive; the other, the negative element in their religion. It is deeply interesting to notice, how the former Pharisee (or "separated one"), Paul, had this in view in tracing the Christian life as that of the true "chasid," and therefore "Nivdal" -- in opposition to the Pharisees of externalism -- in such passages as 2 Corinthians 6:14-7:1, closing with this admonition to "cleanse ourselves from all filthiness  of the flesh and spirit, perfecting holiness in the fear of God." And so St. Paul's former life and thinking seem ever to have served him as the type of the spiritual realities of his new state. 
Two points in Jewish history here claim our special attention, without attempting to unravel the whole somewhat tangled web of events. The first is the period immediately after Alexander the Great. It was one of the objects of the empire which he founded to Grecianise the world; and that object was fully prosecuted by his successors. Accordingly, we find a circle of Grecian cities creeping up along the coast, from Anthedon and Gaza in the south, northwards to Tyre and Seleucia, and eastwards to Damascus, Gadara, Pella, and Philadelphia, wholly belting the land of Israel. Thence the movement advanced into the interior, taking foothold in Galilee and Samaria, and gathering a party with increasing influence and spreading numbers among the people. Now it was under these circumstances, that the "Chasidim" as a party stood out to stem the torrent, which threatened to overwhelm alike the religion and the nationality of Israel. The actual contest soon came, and with it the second grand period in the history of Judaism. Alexander the Great had died in July 323 BC. About a century and a half later, the "Chasidim" had gathered around the Maccabees for Israel's God and for Israel. But the zeal of the Maccabees soon gave place to worldly ambition and projects. When these leaders united in their person the high-priestly with the royal dignity, the party of the "Chasidim" not only deserted them, but went into open opposition. They called on them to resign the high-priesthood, and were ready to suffer martyrdom, as many of them did, for their outspoken convictions. Thenceforth the "Chasidim" of the early type disappear as a class. They had, as a party, already given place to the Pharisees -- the modern "Nivdalim"; and when we meet them again they are only a higher order or branch of the Pharisees -- "the pious" of old having, so to speak, become pietists." Tradition (Men.40) expressly distinguished "the early Chasidim" (harishonim) from "the later" (acheronim). No doubt, those are some of their principles, although tinged with later colouring, which are handed down as the characteristics of the "chasid" in such sayings of the Mishnah as: "What is mine is thine, and what is thine remains thine as well" (P. Ab. V.10); "Hard to make angry, but easy to reconcile" (11); "Giving alms, and inducing others to do likewise" (13); "Going to the house of learning, and at the same time doing good works" (14).
The earliest mention of the Pharisees occurs at the time of the Maccabees. As a "fraternity" we meet them first under the rule of John Hyrcanus, the fourth of the Maccabees from Mattathias (135-105 BC); although Josephus speaks of them already two reigns earlier, at the time of Jonathan (Ant. xiii, 171-173). He may have done so by anticipation, or applying later terms to earlier circumstances, since there can be little doubt that the Essenes, whom he names at the same time, had not then any corporate existence. Without questioning that, to use a modern term, "the direction" existed at the time of Jonathan,  we can put our finger on a definite event with which the origin of "the fraternity" of the Pharisees is connected. From Jewish writings we learn, that at the time of Hyrcanus a commission was appointed to inquire throughout the land, how the Divine law of religious contributions was observed by the people. 
The result showed that, while the "therumah," (see The Temple) or priestly "heave-offerings," was regularly given, neither the first or Levitical tithe, nor yet the so-called "second" or "poor's tithe," was paid, as the law enjoined. But such transgression involved mortal sin, since it implied the personal use of what really belonged to the Lord. Then it was that the following arrangements were made. All that the "country people" ('am ha-aretz) sold was to be considered "demai" -- a word derived from the Greek for "people," and so betraying the time of its introduction, but really implying that it was "doubtful" whether or not it had been tithed. In such cases the buyer had to regard the "therumah," and the "poor's tithe" as still due on what he had purchased. On the other hand, the Pharisees formed a "Chabura," or fraternity, of which each member -- "Chaber," or "companion" -- bound himself to pay these tithes before use or sale. Each "Chaber" was regarded as "neeman," or "credited" -- his produce being freely bought and sold by the rest of the "Chaberim." Of course, the burden of additional expense which this involved to each non-"chaber" was very great, since he had to pay "therumah" and tithe on all that he purchased or used, while the Pharisee who bought from another Pharisee was free. One cannot help suspecting that this, in connection with kindred enactments, which bore very hard upon the mass of the people, while they left "the Pharisee" untouched, may underlie the charge of our Lord (Matt 23:4): "They bind heavy burdens and grievous to be borne, and lay them on men's shoulders; but they themselves will not move them with one of their fingers."
But the rigorous discharge of tithes was only one part of the obligations of a "Chaber." The other part consisted in an equally rigorous submission to all the laws of Levitical purity as then understood. Indeed, the varied questions as to what was, or what made "clean," divided the one "order" of Pharisees into members of various degrees. Four such degrees, according to increasing strictness in "making clean," are mentioned. It would take too long to explain this fourfold gradation in its details. Suffice it, that, generally speaking, a member of the first degree was called a "Chaber," or "Ben hacheneseth," "son of the union" -- an ordinary Pharisee; while the other three degrees were ranked together under the generic name of "Teharoth" (purifications). These latter were probably the "Chasidim" of the later period. The "Chaber," or ordinary Pharisee, only bound himself to tithing and avoidance of all Levitical uncleanness. The higher degrees, on the other hand, took increasingly strict vows. Any one might enter "the order" if he took, before three members, the solemn vow of observing the obligations of the fraternity. A novitiate of a year (which was afterwards shortened) was, however, necessary. The wife or widow of a "Chaber," and his children, were regarded as members of the fraternity. Those who entered the family of a "Pharisee" had also to seek admission into the "order." The general obligations of a "Chaber" towards those that were "without" the fraternity were as follows. He was neither to buy from, nor to sell to him anything, either in a dry or fluid state; he was neither to eat at his table (as he might thus partake of what had not been tithed), nor to admit him to his table, unless he had put on the garments of "Chaber" (as his own old ones might else have carried defilement); nor to go into any burying-place; nor to give "therumah" or tithes to any priest who was not a member of the fraternity; nor to do anything in presence of an "am ha-aretz," or non-"Chaber," which brought up points connected with the laws of purification, etc. To these, other ordinances, partly of an ascetic character, were added at a later period. But what is specially remarkable is that not only was a novitiate required for the higher grades, similar to that on first entering the order; but that, just as the garment of a non-"chaber" defiled a "Chaber" of the first degree, that of the latter equally defiled him of the second degree, and so on. 
To sum up then: the fraternity of the Pharisees were bound by these two vows -- that of tithing and that in regard to purifications. As the most varied questions would here arise in practice, which certainly were not answered in the law of Moses, the "traditions," which were supposed to explain and supplement the Divine law, became necessary. In point of fact, the Rabbis speak of them in that sense, and describe them as "a hedge" around Israel and its law. That these traditions should have been traced up to oral communications made to Moses on Mount Sinai, and also deduced by ingenious methods from the letter of Scripture, was only a further necessity of the case. The result was a system of pure externalism, which often contravened the spirit of those very ordinances, the letter of which was slavishly worshipped. To what arrant hypocrisy it often gave rise, appears from Rabbinical writings almost as much as from the New Testament. We can understand how those "blind guides" would often be as great a trouble to their own party as to others. "The plague of Pharisaism" was not an uncommon expression; and this religious sore is ranked with "a silly pietist, a cunning sinner, and a woman Pharisee," as constituting "the troubles of life" (Sot. iii.4). "Shall we stop to explain the opinions of Pharisees?" asks a Rabbi, in supreme contempt for "the order" as such. "It is as a tradition among the Pharisees," we read (Ab. de R. Nathan, 5), "to torment themselves in this world, and yet they will not get anything in the next." It was suggested by the Sadducees, that "the Pharisees would by-and-by subject the globe of the sun itself to their purifications." On the other hand, almost Epicurean sentences are quoted among their utterances, such as, "Make haste, eat and drink, for the world in which we are is like a wedding feast"; "If thou possessest anything, make good cheer of it; for there is no pleasure underneath the sod, and death gives no respite...Men are like the flowers of the field; some flourish, while others fade away."
"Like the flowers of the field!" What far other teaching of another Rabbi, Whom these rejected with scorn, do the words recall! And when from their words we turn to the kingdom which He came to found, we can quite understand the essential antagonism of nature between the two. Assuredly, it has been a bold stretch of assertion to connect in any way the origin or characteristics of Christianity with the Rabbis. Yet, when we bring the picture of Pharisaism, as drawn in Rabbinical writings, side by side with the sketch of it given by our Lord, we are struck not only with the life-likeness, but with the selection of the distinctive features of Pharisaism presented in His reproofs. Indeed, we might almost index the history of Pharisaism by passages from the New Testament. The "tithing of mint and anise," to the neglect of the weightier matters of the law, and "the cleansing" of the outside -- these twofold obligations of the Pharisees, "hedged around," as they were, by a traditionalism which made void the spirit of the law, and which manifested itself in gross hypocrisy and religious boasting -- are they not what we have just traced in the history of "the order?"
 When speaking of the four degrees in the order of Jesuits, we refer to those which are professed. We are, of course, aware of the existence of the so-called "professi trium votorum" of whom nothing definite is really known by the outside world, and whom we may regard as "the secret Jesuits," and of that of lay and clerical "coadjutors," whose services and vows are merely temporary.  The Greek word for "filthiness" occurs in this passage only, but the verb from which it is derived seems to have a ceremonial allusion attaching to it in the three passages in which it is used: 1 Corinthians 8:7; Revelation 3:4, 14:4.  If St. Paul was originally a Pharisee, the accounts given by the earliest tradition (Euseb. H. E. ii. 23), compared with that of Josephus (Ant. xx, 197-203), would almost lead us to infer that St. James was a "Chasid." All the more significant would then be the part he took in removing the yoke of the law from the Gentile converts (Acts 15:13-21).  In proof of this, it may be stated that before the formal institution of the "order," R. Jose, the son of Joezer, declared all foreign glass vessels, and indeed the whole soil of heathen lands, "unclean," thus "separating" Israel from all possible intercourse with Gentiles.  It may be to the decrees then enacted by Hyrcanus that Josephus refers (Ant. xiii, 293-298), when he speaks of their "abolition" after Hyrcanus broke with the Pharisaical party.  It is impossible here to reproduce the Talmudical passages in evidence. But the two obligations of "making clean" and of "tithing," together with the arrangement of the Pharisees into various grades, are even referred to in the Mishnah (Chag. ii. 5, 6 and , and Demai ii. 2,3).
 The Greek word for "filthiness" occurs in this passage only, but the verb from which it is derived seems to have a ceremonial allusion attaching to it in the three passages in which it is used: 1 Corinthians 8:7; Revelation 3:4, 14:4.
 If St. Paul was originally a Pharisee, the accounts given by the earliest tradition (Euseb. H. E. ii. 23), compared with that of Josephus (Ant. xx, 197-203), would almost lead us to infer that St. James was a "Chasid." All the more significant would then be the part he took in removing the yoke of the law from the Gentile converts (Acts 15:13-21).
 In proof of this, it may be stated that before the formal institution of the "order," R. Jose, the son of Joezer, declared all foreign glass vessels, and indeed the whole soil of heathen lands, "unclean," thus "separating" Israel from all possible intercourse with Gentiles.
 It may be to the decrees then enacted by Hyrcanus that Josephus refers (Ant. xiii, 293-298), when he speaks of their "abolition" after Hyrcanus broke with the Pharisaical party.
 It is impossible here to reproduce the Talmudical passages in evidence. But the two obligations of "making clean" and of "tithing," together with the arrangement of the Pharisees into various grades, are even referred to in the Mishnah (Chag. ii. 5, 6 and , and Demai ii. 2,3).