From his earliest years St Francis of Assisi was being groomed to follow his father into his thriving cloth business, which had enriched the Bernardone family, making it one of the wealthiest in Assisi. His education at the school conducted by the canons of San Rufino was tailored for him to follow his father into business. Although the hagiographical tradition was rather tight-lipped about Francis's activities prior to his conversion, the commercial world sometimes intrudes into Franciscan hagiography. As a young man, Francis worked in his parents’ premises in Assisi and on occasion he travelled to the great fairs of France, purchasing cloth to be delivered to Assisi. He sided with his friends and neighbours in the civil war which erupted in the city of his birth. He fought and was captured at the battle of Collestrada in November 1202 and spent more than a year as a prisoner of war in Perugia, the implacable foe of Assisi. This period gave Francis ample time to re-evaluate his young life. He returned to Assisi as a different man. The young man who had led the revels of his friends in the Umbrian city had changed. Now he was withdrawn, removed. His attitude towards money was slowly changing, too, as the sequence of events leading to his conversion demonstrates. Money played a prominent part in his conversion, especially his lack of generosity towards a pauper seeking alms in his shop. Events at the fair in Foligno would shape his future. His dissatisfaction with his earlier life prompted him to re-visit the contents of the Gospel, which became his light and guide. He noted that Jesus and his followers were detached from material possessions and they had shed possessions to free them for the task of evangelisation. Meditations on the Gospel showed Francis that Jesus had renounced his material possessions for the spiritual enrichment of humanity. His reflection on evangelical poverty brought him to a greater realisation of the importance of self-emptying in the redemption achieved by the Deus homo. The proclamation of the Gospel during the celebration of mass at the Portiuncula spelled out the conditions in which the disciples should present the good news to their neighbours. This message was reinforced by his having the book of the Gospels opened thrice at random, when he and Bernard of Quintavalle sought guidance for their religious life in the church of San Nicolò di Piazza. One preacher concluded that St Francis wished to found an order on nothing.

The five chapters of this monograph trace the evolution of the friars’ thoughts regarding money, beginning with St Francis and the evolution of his Rule. They are preceded by a lengthy introduction and an epilogue consisting of a reprise of the order's economic thought. The first chapter works towards the definition of evangelical poverty among the friars and focuses on the experience of the saint, the establishment of the fraternity, the role of the papacy, and references to evangelical poverty in the Regula non bullata of 1221 and the Regula bullata of 1223. The radical nature of the order's evangelical poverty led Francis to choose the words sine proprio rather than paupertas in the opening chapters of the Regula bullata and the Regula non bullata. Thornton reminds readers that St Francis and his followers resembled other penitential groups of this period and he notes the genesis of the term sine proprio which appears in the two recensions of the Franciscan Rule. The same format – sine proprio – had earlier featured in Innocent iii's approval of the Rule of the Trinitarians on 17 December 1198 – ‘qui minister vocabitur, in castitate et sine proprio vivant’ (p. 41 n. 70). Was the term derived from Innocent iii? Franciscan hagiography claimed that the Rule was dictated by the Holy Spirit. How original was Francis? Or was the term derived from the order of Trinitarians? Was the term in common parlance to depict the process of self-emptying in ascetical and devotional literature? Franciscan hagiography does not offer any information on the deployment of the term and Thornton does not linger to address these questions more fully.

The history of the Franciscan order in the thirteenth century was inextricably connected with the papacy and the series of decisions and declarations. Accordingly, the development of the friars’ economic thought from St Francis to the Black Death is traced. Francis served as the ultimate authority in the rapidly expanding movement, which had attained a membership of some 5,000 by the time of the celebrated chapter of the mats. The Compilatio Assisiensis depicted a stream of friars seeking the saint's approval for items such as breviaries and books. The moral vacuum which followed the death of St Francis on the evening of 3 October 1226 persisted into successive years and decades. John Parenti, minister-general (1227–32), found himself in a critical period for the development of the nascent order, which was already well established throughout Italy, France, Germany, Spain, Portugal and England. Parenti's authority, however, was unable to arbitrate on disputes about the Rule. The general chapter of 1230 confirmed that even the minister-general lacked the charism to offer authoritative guidance. Maimed by a lack of internal authority, the general chapter sent a delegation of friars to Gregory ix, formerly Cardinal Hugolino, for authoritative guidance. The pope declared that he knew the mind of the saint in drafting the Rule. Moreover, he responded quickly on 28 September 1230 by promulgating Quo elongati, the first papal interpretation of the order's Rule. This declaration did not escape bitter controversy, especially the debates spilled over into the hagiographical tradition. Recognising the friars’ scruples, he decreed that the Testament was not binding upon the friars. Innocent iv's Ordinem vestrum on 14 November 1245 ‘tried to take things a stage further’, in the words of Bishop John R. H. Moorman. It decreed that property used by the friars belonged to the papacy. Some friars experienced scruples about adopting the provisions of the new document which went further than Gregory ix's Quo elongati. The general chapter of Genoa in 1251 voted to abstain from following the provisions of Innocent iv's decree, where they exceeded Quo elongati. The general chapter of Narbonne referred to the decision of the previous general chapter of Metz held in 1254: This was then reaffirmed in the constitutions of Narbonne: ‘As was decided in the chapter of Metz (1254). The declaration of the Lord pope Innocent (iv) shall remain suspended, and we strictly forbid anyone to use it in those points which in which it contradicts the declaration of the Lord Pope Gregory’ (ix).

One of the most important papal interventions came under Nicholas iii, a devotee of St Francis. His Exiit qui seminat was promulgated on 14 August 1279 and it attempted to resolve the debates about aspects of Franciscan identity once and for all. The pope brought together a group of Franciscan theologians, including Peter of John Olivi, and ministers provincial. Two Franciscan cardinals, Jerome of Ascoli, formerly minister-general, and Bentivenga dei Bentivenghi, formerly bishop of his native Todi, were also consulted. The former was to become the first Franciscan pope under the name of Nicholas iv (1288–92). Exiit qui seminat imposed a ban on further discussion of the matter. Thornton believes that Clement v sided with Ubertino da Casale and his colleagues. The debates which took place at the papal court of Avignon in 1310 and 1311 played an important part in the preparation of Clement v's Exivi de paradiso of 6 May 1312. The reformers gained in stature and moral authority during these debates, which were not treated adequately by the friars of the community, the forerunners of the Friars Minor Conventual. Thornton paid little attention to the official position of the order. Nicholas iii's ban on further discussion was re-visited by John xxii and nullified by his constitution, Ad conditorem, on 8 December 1322. Similarly, John xxii's Cum inter nonnullos of 12 November 1323 re-examined the nature of the poverty lived by the Son of God. In addition, the pertinent writings of four Franciscan theologians were considered: Peter of John Olivi, John Duns Scotus, the doctor subtilis, William of Ockham and Gerald Odonis. The author makes no use of the commentaries on the friars’ Rule. This attractive volume guides readers through the web of arguments which arose within the Franciscan tradition. In selecting a papal framework for the first century of the order's history, Thornton offers a path to the comprehension of the major documents and their impact and his volume will be warmly welcomed by students of Franciscan and papal history.