The following information (even where not directly quoted) was taken primarily from Chapters 2-5 of the 
Handbook of the Third Order Secular of St. Francis of Assisi (out of print), by Basil Gummerman, O.F.M. Cap. Patterson, NJ: St. Anthony’s Guild, 1947.
What is the Third Order of St. Francis?
The Third Order Secular of St. Francis is an ecclesiastical 
association of the laity, originally founded by St. Francis of Assisi. 
It is a state of perfection for persons living in the world. The 
religious strive after perfection by observing the three vows of 
poverty, chastity, and obedience and live in community according to 
their Rule, whereas the members of the Third Order Secular live in the 
spirit of the vows in fraternal unity according their own separate Rule 
(Ch. 2, Third Order Handbook).
  
Pope Leo XIII explained that while all the Franciscan Orders are 
ordered to the perfection of their members, unlike the first two 
Franciscan Orders, “
open to few…the Third Order… is accommodated to the many” (Constitution 
Misericors Filius). Even so, the Third Order is not indiscriminately open to all, and there are times of probation (
i.e., the postulancy & novitiate), before one may be professed for life in the Order.
What is the purpose of the Third Order?
The purpose of secular Third Orders in the Church is the same as that
 of religious orders and congregations: they promote Christian 
perfection. And St. Francis had no other end in view when he established
 his Third Order. It is easily understood, then, that “
the first essential duty of Franciscan Tertiaries [Third Order members] 
is the striving after perfection by faithfully observing the Rule” (Ch. 3, T.O. Handbook).
  
Pope St. Pius X proclaimed that the purpose of the Third Order of St. Francis consists in this: “
that
 its members put into everyday practice the precepts of Gospel 
perfection and serve as models of Christian life for the imitation of 
others” (
Tertium Franciscalium Ordinem, September 8, 1912).
What is the spirit of the Franciscan Order?
Every religious order has its specific spirit. It is the founder who,
 with his particular ideals, outstanding virtues, and activities gives 
his order its spirit. In St. Francis we see seraphic love, extreme 
poverty, deep humility, great penance and a chivalrous life according to
 the Gospel. Yet, how can one concisely express his spirit? Perhaps the 
best way is to say that his spirit consists in living out fully, the 
whole Gospel—not only its commands, but also its precepts, ideals and 
implications. As his first biographer, Thomas of Celano wrote:
  
He was the man with the evangelical vocation in truth and
 in faith the servant of the Gospel…His supreme desire, his ardent wish 
and his highest principle was to observe the Gospel in all things and 
above all things (Ch. 3, T.O. Handbook).
While other founders concentrated on one or the other characteristics
 of Christ such as zeal for souls or love of prayer, St. Francis 
concentrated on imitating Christ, the Divine Model as He is pictured in 
the Gospel. Thus, “
St. Francis approached God through the Sacred Humanity of Christ. This is the Gospel way, the way best adapted to human nature”
 (Ch. 3, T.O. Handbook). From this we see the reason for Francis’s great
 devotion to the Babe in the Manger, the Man of Sorrows upon the Cross, 
as well as the Body and Blood of Jesus Christ in the Most Blessed 
Sacrament. Pope Pius XI has stated that in no other saint have the image
 of Christ and the ideal of the Gospel been more faithfully and 
strikingly expressed than in Francis who has been justly styled “
the second Christ” (Encyclicals 
Auspicato, Sacra Propediem, Rite Expiatis).
  
To acquire the Franciscan spirit Tertiaries are called to:
frequently fix their attention on Jesus Christ and 
endeavor to copy one trait after the other according to their station in
 life. Prayerful reading of the Gospel and regular meditation will fill 
their minds with Jesus so as to enkindle love for Him in their hearts, 
and move their wills to imitate Him. Observance of the letter and spirit
 of the Rule will detach them from the world and self and awaken a 
longing and a taste for intimate communion with Jesus (Ch. 3, T.O. 
Handbook).
Advantages of the Third Order
Following the spirit and letter of the Rule, members of the Third Order of St. Francis find “
a safe refuge in a sinful world and an excellent nursery of the choicest virtues.” “
By its wise restrictions and abundant graces the Third Order provides a security akin to that of the cloister.” Thus, the Tertiary vocation “
is a great grace, approximating the call to religious life”
 (Ch. 5, T.O. Handbook). The various apostolates of the Third Order 
gives the Tertiary many opportunities to merit through the works of 
mercy.
   
The Tertiary has more help in the spiritual life than the rest of the
 faithful. Besides the Rule, so wisely constructed for those who seek 
holiness of life while living in this sinful world, he also has the “
glorious examples of the holy Franciscans to guide him,”
 and he has claim to a special share in the good works of the Three 
Orders that will support his efforts. Furthermore, in those places where
 the Third Order is already established, he has the advantage of “
novice
 instructions and monthly conferences to unfold the beauty and value, 
the means and obstacles of the spiritual life, and to explain the 
application of the spirit of St. Francis to modern everyday life” 
(Ch. 5, T.O. Handbook). And, being in fraternal union with other 
Tertiaries who hold the same lofty Franciscan ideals is a priceless 
assistance providing joy and strength to persevere in this holy way of 
life.
  
All Tertiaries have the great privilege and duty of joining in the 
Public Prayer of the Church—the Divine Office. With the clergy and 
religious throughout the world, they become ambassadors of the Church, 
to officially offer praise to God in the name of all humanity. Yet, 
because the laity must live in the busy world, holy Church, wise mother 
that she is, has given her Tertiary children the choice of a much 
simpler office suited to their station in life known as the Office of 
the Paters or the Seraphic Office. This option makes it possible for 
persons of virtually any station in life to faithfully pray the daily 
office.
  
There are also, throughout the year, eight Franciscan feasts in which Tertiaries can gain plenary indulgences.
  
The fruit of the Third Order
The Third Order of St. Francis has done so much good over the 
centuries both in the sanctification of souls and in the building up of 
Christian society that many Popes have been moved to sing its praises. 
The number Franciscan Tertiaries now listed as Saints or Blesseds is 
enormous. As to its effect in the social sphere, Pope Pius XI stated:
A most wholesome change in society began to take shape, 
the new Order founded by Francis spreading far and wide among the 
peoples of Christendom and gaining in its members, while moral purity 
followed in the wake of the practice of penance. …There was a beautiful,
 glorious revival of the choicest virtues in civil life. In fine the 
face of the earth was renewed” (Rite Expiatis).
Conditions for Entry to the Third Order of St. Francis under the 
Friars Minor Capuchin of Traditional Observance of Morgon, France:
- Candidates must be above the age of fourteen, in good character,
 peace-loving, and above all of tried fidelity in the practice of the 
Catholic Faith and in loyalty to the Roman Church and the Apostolic See.
 They must be in accord with the doctrinal position of the Capuchin 
Fathers of Morgon, France and the Priestly Society of St. Pius X.
- Married women may not be received without the husband’s knowledge and consent, unless their confessor judges otherwise.
- One must not belong to another Third Order.
- Church law mandates that candidates undertake at least one year of 
novitiate before making their profession (the Capuchins of Morgon 
require 1½ years). At profession the candidates promise to observe the 
Rule for the rest of their lives.
A Synopsis of the Third Order Rule
- Simplicity and modesty in dress.
- Keeping away from dances and shows which savor of license and avoiding all forms of dissipation.
- Temperance in eating and drinking.
- Fasting and abstinence on particular days.
- Monthly Confession and Holy Communion.
- Praying daily one of three Offices approved by the Church.
- Making a last will and testament.
- Leading others by setting a good example.
- Maintaining charity towards others.
- Refraining from taking unnecessary oaths and using indecent language.
- Attending Mass daily when possible and attending the monthly meetings.
- Contributing to a common fund for the needs of poor members and for the dignity of worship.
- Visiting sick members.
- Praying for deceased members.
Helpful information for those seeking to join the traditional Third Order of St. Francis
Directed by the traditional Capuchin Franciscans of Morgon, France
  
I. About Tertiary Life: Postulancy, Novitiate (habit, novice meetings), Profession, and Rule
  
A. POSTULANCY: Ordinarily, where there are 
established Fraternities of the Third Order, there is a postulancy 
period of at least 3 months for those seeking entrance. “
Postulants shall be briefly instructed in Christian doctrine, in the life of our holy Father Francis, and in the Third Order”
 (Const. Art. 12). Where there is no fraternity (as would be the case 
here), candidates enter as Isolated Tertiaries and the postulancy period
 is waved. At the end of the postulancy, “
those who have been found 
suitable shall be admitted to the novitiate of the fraternity by the 
Director on the advice of the Council” (Const. Art. 15).
  
B. NOVITIATE: According to the Rule (and Church law)
 the novitiate must last at least one full and uninterrupted year. 
Because of the current difficult circumstances, the Capuchins of Morgon 
have extended the length of the novitiate for all their Third Order 
novices to 18 months.
- The Novitiate begins with a clothing ceremony in which the 
candidate receives the habit of the Third Order: A large brown scapular 
and a cord with 5 (or 3) knots—both worn under one’s clothing. One 
chooses a new name on this day.
- The purpose of this time of probation is two-fold: 1) To give the 
novices the opportunity to test their strength and perseverance. 2) To 
enable the fraternity to ascertain their fitness.
- Besides the usual monthly meetings of the Society that they are 
required to attend, there are Novice Instruction meetings (also usually 
held once a month). It is of utmost importance that the Novices attend 
all the NI’s. The NI’s are intended “to prepare the novices that 
they may afterwards dedicate themselves to God by profession, with a 
full realization of their obligations” (Const. Art. 20). In these 
Instructions the novice will learn about the life and spirit of St. 
Francis, the nature, purpose and history of the Third Order, the 
regulations of the Holy Rule, and how to attain perfection while living 
in the tumult of the world. They will also learn the works of piety, 
charity and of the apostolates of Tertiary life.
- “Towards the end of the novitiate the Director, if he thinks 
fit, shall test the knowledge and intentions of the novices, and seek 
the advice of the Council as to whether they are worthy of being 
admitted to profession” (Const. Art. 23).
C. PROFESSION: “
Profession in the Third Order is
 a solemn religious act whereby one of the faithful, moved by divine 
grace, dedicates himself to God, promising to observe the holy Gospel of
 our Lord Jesus Christ in the world, by living according to the 
commandments of God and the Rule of our holy Father Francis….” Those who profess are not bound by vows but by a promise, which is not binding under pain of sin. Profession is for life.
  
II. Preliminary requirements
  
A. From the Rule Ch. 1§1: “
Only those may be received as members 
who have completed their 14th year, and are of good character, 
peace-loving, and above all of tried fidelity in the practice of the 
Catholic Faith and in loyalty to the Roman Church and the Apostolic See.”
  
B. From the Rule Ch. 1§2: “
Married women may not be received without the husband’s knowledge and consent, unless their confessor judges otherwise.”
  
C. Const. Art. 11: “
Since the continual growth of the Third Order
 should be in holiness rather than in numbers, careful inquiry shall be 
made whether candidates are fit for entry into the Order, according to 
the conditions laid down in the Rule and these Constitutions. Those are 
fit for membership, who, called by divine grace, desire to dedicate 
themselves to God in a special way in the world; that is, wish to be 
pleasing to God and to be of service to the Church and to human society 
according to the spirit of St. Francis.”
  
D. Further Requirements
- Required by the traditional Capuchins of Morgon, France: Candidates must be “in
 accord with the doctrinal position of the Capuchin Fathers of Morgon 
and the priests of the Society of St. Pius X in the present religious 
combat.”
- One must not already be a member of another Third Order (only with a
 special indult may one belong to two Third Orders [Const. Art. 13]). It
 is possible—under the proper conditions—to switch from one order to 
another.
- One must have decided to combat the spirit of the world, to respect 
the rules of Christian modesty in dress (Pope Benedict XV called the 
Tertiary sisters to be “an object lesson of holy modesty to other 
matrons and maidens), to master one’s language and as to avoid gossip 
and vain quarrels."
- One must be ready to follow the formation program for the postulancy
 and the novitiate, and to participate at the regular (monthly) meetings
 of the Fraternity (except in the case of a major impediment). Note: As 
noted above, ordinarily, where there are established Fraternities of the
 Third Order, there is a 3-month postulancy period for those seeking 
entrance. Where there is no fraternity (as would be the case here), the 
postulancy period is waved.
III. How to apply:
A. Be sure that you SATISFY THE PRELIMINARY CONDITIONS for becoming a Franciscan Tertiary.
  
B. FIND A PRIEST who is familiar with you (your director, confessor, pastor or one who has been any of these in the past).
  
C. ASK THIS PRIEST to write a letter recommending you to the Third Order. This letter is to be addressed and sent to:
  
Rev. Jacques Emily
St. Aloysius Gonzaga Retreat House
19101 Bear Creek Road
Los Gatos, CA 95033
(or the current Director of the Franciscan Third Order)
  
D. GIVE THIS PRIEST a copy of the letter entitled: “TO BECOME A 
FRANCISCAN TERTIARY,” which is signed and sealed by the Capuchins of 
Morgon. This letter lists the required dispositions of a candidate to 
the Third Order, and thus it gives the priest a guide for determining 
whether or not the petitioner is fit. He will need to have this before 
he can write a letter of recommendation.
  
E. INVESTITURE: After this, Fr. Emily may pay a visit (if there are a
 good number) for the investiture ceremony in which the candidates 
receive the habit and are enrolled as novices. If Fr. Emily does not 
come to conduct the ceremony himself, he will give faculties to your 
local priest to conduct the ceremonies.
Contact Information for the traditional Third Order of St. Francis: SSPX Los Gatos