As it is Lent season, I thought it appropriate to provide some background on the meaning and history.
Origin of the word
The Teutonic word Lent, which we employ to denote the forty days' fast preceding Easter, originally meant no more than the spring season. Still it has been used from the Anglo-Saxon period to translate the more significant Latin term quadragesima (French carême, Italian quaresima, Spanish cuaresma), meaning the "forty days", or more literally the "fortieth day". This in turn imitated the Greek name for Lent, tessarakoste (fortieth), a word formed on the analogy of Pentecost (pentekoste), which last was in use for the Jewish festival before New Testament times. This etymology, as we shall see, is of some little importance in explaining the early developments of the Easter fast.
Origin of the custom
Some of the Fathers as early as the fifth century supported the view that this forty days' fast was of Apostolic institution. For example, St. Leo (d. 461) exhorts his hearers to abstain that they may "fulfill with their fasts the Apostolic institution of the forty days" — ut apostolica institutio quadraginta dierum jejuniis impleatur (P.L., LIV, 633), and the historian Socrates (d. 433) and St. Jerome (d. 420) use similar language (P.G., LXVII, 633; P.L., XXII, 475).
But the best modern scholars are almost unanimous in rejecting this view, for in the existing remains of the first three centuries we find both considerable diversity of practice regarding the fast before Easter and also a gradual process of development in the matter of its duration. The passage of primary importance is one quoted by Eusebius (Church History V.24) from a letter of St. Irenaeus to Pope Victor in connection with the Easter controversy. There Irenaeus says that there is not only a controversy about the time of keeping Easter but also regarding the preliminary fast. "For", he continues, "some think they ought to fast for one day, others for two days, and others even for several, while others reckon forty hours both of day and night to their fast". He also urges that this variety of usage is of ancient date, which implies that there could have been no Apostolic tradition on the subject. Rufinus, who translated Eusebius into Latin towards the close of the fourth century, seems so to have punctuated this passage as to make Irenaeus say that some people fasted for forty days. Formerly some difference of opinion existed as to the proper reading, but modern criticism (e.g., in the edition of Schwartz commissioned by the Berlin Academy) pronounces strongly in favor of the text translated above. We may then fairly conclude that Irenaeus about the year 190 knew nothing of any Easter fast of forty days.
The same inference must be drawn from the language of Tertullian only a few years later. When writing as a Montanist, he contrasts the very slender term of fasting observed by the Catholics (i.e., "the days on which the bridegroom was taken away", probably meaning the Friday and Saturday of Holy Week) with the longer but still restricted period of a fortnight which was kept by the Montanists. No doubt he was referring to fasting of a very strict kind (xerophagiæ — dry fasts), but there is no indication in his works, though he wrote an entire treatise "De Jejunio", and often touches upon the subject elsewhere, that he was acquainted with any period of forty days consecrated to more or less continuous fasting (see Tertullian, On Fasting 2 and 14; cf. On Prayer 18; etc.).
And there is the same silence observable in all the pre-Nicene Fathers, though many had occasion to mention such an Apostolic institution if it had existed. We may note for example that there is no mention of Lent in St. Dionysius of Alexandria (ed. Feltoe, 94 sqq.) or in the "Didascalia", which Funk attributes to about the yearkú yet both speak diffusely of the paschal fast.
Further, there seems much to suggest that the Church in the Apostolic Age designed to commemorate the Resurrection of Christ, not by an annual, but by a weekly celebration (see "The Month", April 1910, 337 sqq.). If this be so, the Sunday liturgy constituted the weekly memorial of the Resurrection, and the Friday fast that of the Death of Christ. Such a theory offers a natural explanation of the wide divergence which we find existing in the latter part of the second century regarding both the proper time for keeping Easter, and also the manner of the paschal fast. Christians were at one regarding the weekly observance of the Sunday and the Friday, which was primitive, but the annual Easter festival was something superimposed by a process of natural development, and it was largely influenced by the conditions locally existing in the different Churches of the East and West. Moreover, with the Easter festival there seems also to have established itself a preliminary fast, not as yet anywhere exceeding a week in duration, but very severe in character, which commemorated the Passion, or more generally, "the days on which the bridegroom was taken away".
Be this as it may, we find in the early years of the fourth century the first mention of the term tessarakoste. It occurs in the fifth canon of the Council of Nicea (A.D. 325), where there is only question of the proper time for celebrating a synod, and it is conceivable that it may refer not to a period but to a definite festival, e.g., the Feast of the Ascension, or the Purification, which Ætheria calls quadragesimæ de Epiphania. But we have to remember that the older word, pentekoste (Pentecost) from meaning the fiftieth day, had come to denote the whole of the period (which we should call Paschal Time) between Easter Sunday and Whit-Sunday (cf. Tertullian, On Idolatry 14, — "pentecosten implere non poterunt"). In any case it is certain from the "Festal Letters" of St. Athanasius that in 331 the saint enjoined upon his flock a period of forty days of fasting preliminary to, but not inclusive of, the stricter fast of Holy Week, and secondly that in 339 the same Father, after having traveled to Rome and over the greater part of Europe, wrote in the strongest terms to urge this observance upon the people of Alexandria as one that was universally practiced, "to the end that while all the world is fasting, we who are in Egypt should not become a laughing-stock as the only people who do not fast but take our pleasure in those days". Although Funk formerly maintained that a Lent of forty days was not known in the West before the time of St. Ambrose, this is evidence which cannot be set aside.
Duration of the fast
In determining this period of forty days the example of Moses, Elias, and Christ must have exercised a predominant influence, but it is also possible that the fact was borne in mind that Christ lay forty hours in the tomb. On the other hand just as Pentecost (the fifty days) was a period during which Christians were joyous and prayed standing, though they were not always engaged in such prayer, so the Quadragesima (the forty days) was originally a period marked by fasting, but not necessarily a period in which the faithful fasted every day. Still, this principle was differently understood in different localities, and great divergences of practice were the result. In Rome, in the fifth century, Lent lasted six weeks, but according to the historian Socrates there were only three weeks of actual fasting, exclusive even then of the Saturday and Sunday and if Duchesne's view may be trusted, these weeks were not continuous, but were the first, the fourth, and sixth of the series, being connected with the ordinations (Christian Worship, 243). Possibly, however, these three weeks had to do with the "scrutinies" preparatory to Baptism, for by some authorities (e.g., A.J. Maclean in his "Recent Discoveries") the duty of fasting along with the candidate for baptism is put forward as the chief influence at work in the development of the forty days. But throughout the Orient generally, with some few exceptions, the same arrangement prevailed as St. Athanasius's "Festal Letters" show us to have obtained in Alexandria, namely, the six weeks of Lent were only preparatory to a fast of exceptional severity maintained during Holy Week. This is enjoined by the "Apostolic Constitutions" (V.13), and presupposed by St. Chrysostom (Hom. xxx in Gen., I). But the number forty, having once established itself, produced other modifications. It seemed to many necessary that there should not only be fasting during the forty days but forty actual fasting days. Thus we find Ætheria in her "Peregrinatio" speaking of a Lent of eight weeks in all observed at Jerusalem, which, remembering that both the Saturday and Sunday of ordinary weeks were exempt, gives five times eight, i.e., forty days for fasting. On the other hand, in many localities people were content to observe no more than a six weeks' period, sometimes, as at Milan, fasting only five days in the week after the oriental fashion (Ambrose, "De Elia et Jejunio", 10). In the time of Gregory the Great (590-604) there were apparently at Rome six weeks of six days each, making thirty-six fast days in all, which St. Gregory, who is followed therein by many medieval writers, describes as the spiritual tithing of the year, thirty-six days being approximately the tenth part of three hundred and sixty-five. At a later date the wish to realize the exact number of forty days led to the practice of beginning Lent upon our present Ash Wednesday, but the Church of Milan, even to this day, adheres to the more primitive arrangement, which still betrays itself in the Roman Missal when the priest in the Secret of the Mass on the first Sunday of Lent speaks of "sacrificium quadragesimalis initii", the sacrifice of the opening of Lent.
Nature of the fast
Neither was there originally less divergence regarding the nature of the fast. For example, the historian Socrates (Church History V.22) tells of the practice of the fifth century: "Some abstain from every sort of creature that has life, while others of all the living creatures eat of fish only. Others eat birds as well as fish, because, according to the Mosaic account of the Creation, they too sprang from the water; others abstain from fruit covered by a hard shell and from eggs. Some eat dry bread only, others not even that; others again when they have fasted to the ninth hour (three o'clock) partake of various kinds of food". Amid this diversity some inclined to the extreme limits of rigor. Epiphanius, Palladius, and the author of the "Life of St. Melania the Younger" seem to contemplate a state of things in which ordinary Christians were expected to pass twenty-four hours or more without food of any kind, especially during Holy Week, while the more austere actually subsisted during part or the whole of Lent upon one or two meals a week (see Rampolla, "Vita di. S. Melania Giuniore", appendix xxv, p. 478). But the ordinary rule on fasting days was to take but one meal a day and that only in the evening, while meat and, in the early centuries, wine were entirely forbidden. During Holy Week, or at least on Good Friday it was common to enjoin the xerophagiæ, i.e., a diet of dry food, bread, salt, and vegetables.
There does not seem at the beginning to have been any prohibition of lacticinia, as the passage just quoted from Socrates would show. Moreover, at a somewhat later date, Bede tells us of Bishop Cedda, that during Lent he took only one meal a day consisting of "a little bread, a hen's egg, and a little milk mixed with water" (Church History III.23), while Theodulphus of Orleans in the eighth century regarded abstinence from eggs, cheese, and fish as a mark of exceptional virtue. None the less St. Gregory writing to St. Augustine of England laid down the rule, "We abstain from flesh meat, and from all things that come from flesh, as milk, cheese, and eggs." This decision was afterwards enshrined in the "Corpus Juris", and must be regarded as the common law of the Church. Still exceptions were admitted, and dispensations to eat "lacticinia" were often granted upon condition of making a contribution to some pious work. These dispensations were known in Germany as Butterbriefe, and several churches are said to have been partly built by the proceeds of such exceptions. One of the steeples of Rouen cathedral was for this reason formerly known as the Butter Tower. This general prohibition of eggs and milk during Lent is perpetuated in the popular custom of blessing or making gifts of eggs at Easter, and in the English usage of eating pancakes on Shrove Tuesday.
Relaxations of the lenten fast
From what has been said it will be clear that in the early Middle Ages Lent throughout the greater part of the Western Church consisted of forty weekdays, which were all fast days, and six Sundays. From the beginning to the end of that time all flesh meat, and also, for the most part, "lacticinia", were forbidden even on Sundays, while on all the fasting days only one meal was taken, which single meal was not permitted before evening. At a very early period, however (we find the first mention of it in Socrates), the practice began to be tolerated of breaking the fast at the hour of none, i.e., three o'clock. We learn in particular that Charlemagne, about the year 800, took his lenten repast at 2 p.m. This gradual anticipation of the hour of dinner was facilitated by the fact that the canonical hours of none, vespers, etc., represented rather periods than fixed points of time. The ninth hour, or none, was no doubt strictly three o'clock in the afternoon, but the Office of none might be recited as soon as sext, which, of course, corresponded to the sixth hour, or midday, was finished. Hence none in course of time came to be regarded as beginning at midday, and this point of view is perpetuated in our word noon which means midday and not three o'clock in the afternoon. Now the hour for breaking the fast during Lent was after Vespers (the evening service), but by a gradual process the recitation of Vespers was more and more anticipated, until the principle was at last officially recognized, as it is at present, that Vespers in lent may be said at midday. In this way, although the author of the "Micrologus" in the eleventh century still declared that those who took food before evening did not observe the lenten fast according to the canons (P.L., CLI, 1013), still, even at the close of the thirteenth century, certain theologians, for example the Franciscan Richard Middleton, who based his decision in part upon contemporary usage, pronounced that a man who took his dinner at midday did not break the lenten fast.
Still more material was the relaxation afforded by the introduction of "collation". This seems to have begun in the ninth century, when the Council of Aix la Chapelle sanctioned the concession, even in monastic houses, of a draught of water or other beverage in the evening to quench the thirst of those who were exhausted by the manual labor of the day. From this small beginning a much larger indulgence was gradually evolved. The principle of parvitas materiae, i.e., that a small quantity of nourishment which was not taken directly as a meal did not break the fast, was adopted by St. Thomas Aquinas and other theologians, and in the course of centuries a recognized quantity of solid food, which according to received authorities must not exceed eight ounces, has come to be permitted after the midday repast. As this evening drink, when first tolerated in the ninth-century monasteries, was taken at the hour at which the "Collationes" (Conferences) of Abbot Cassian were being read aloud to the brethren, this slight indulgence came to be known as a "collation", and the name has continued since.
Other mitigations of an even more substantial character have been introduced into lenten observance in the course of the last few centuries. To begin with, the custom has been tolerated of taking a cup of liquid (e.g., tea or coffee, or even chocolate) with a fragment of bread or toast in the early morning. But, what more particularly regards Lent, successive indults have been granted by the Holy See allowing meat at the principal meal, first on Sundays, and then on two, three, four, and five weekdays, throughout nearly the whole of Lent. Quite recently, Maundy Thursday, upon which meat was hitherto always forbidden, has come to share in the same indulgence. In the United States, the Holy See grants faculties whereby working men and their families may use flesh meat once a day throughout the year, except Fridays, Ash Wednesday, Holy Saturday, and the vigil of Christmas. The only compensation imposed for all these mitigations is the prohibition during Lent against partaking of both fish and flesh at the same repast.