There is a controversy among the scholars as to whether Guru Nanak was a revolutionary or a reformer.Writers like G.C Narang, Hari Ram Gupta, Payane and Griffin are of the view that Guru Nanak was a great reformer. He belonged to the family of Bhakti Reformers and the fundamentals of his teachings did not differ much from those of Bhakats who preceded him.

On the other hand, scholars like Macaullife, Bhai Kahan Singh, Dr. J. S. Grewal, and many others are of the view that the Guru was a revolutionary and not a reformer because he had strongly condemned the then existing religious and social institutions prevailing among both the Hindus and the Muslims. He had laid the foundation of a new casteless and classless society.

The views of the two groups of writers may be discussed as under :

First View-Guru Nanak as a Reformer :

(1).Guru Nanak did not condemn the principles of Hinduism and Islam in their original form :

Guru Nanak did not attack the fundamental principles of either Hinduism or Islam. He did not condemn the institutions of these religions in their original or pure forms. What Guru Nanak denounced was the corrupt and evil practices and rituals which had crept in his time and the exploitation of the ignorant masses by the corrupt and greedy Brahmins and Mullas. Nanak along with Kabir believed that the Vedas and the Kitab (Quran), were not false-it were those persons who were false and misguided, who did not properly study and understand their teachings. Nanak tells, "Ved Kitab mat jutha, jutha so jo na vichare." It were the people who did not follow the instructions and teachings contained in the Vedas and Puranas who failed to take advantage of their teachings. What Nanak wanted to point out to the people was that they should mould their daily life according to the wisdom contained in the Vedas.One must realise the difference between an attack on scripturalism and one on the scriptures themelves." According to him, Nanak denounced scripturalism and not the Hindu or Muslim scriptures. He told all the people that mere reading of the scriptures without love for the Supreme Being was a secular occupation and not a religious practice.

(2) No disrespect to Hindu gods :

Guru Nanak did not show disrespect to Hindu Avtars and divinities. When he challenged the sacrosanct position of the Hindu gods, he simply wanted to tell his devotees that the Hindu gods and goddesses were different from One True Lord. He rather stressed that they were under the command of One Supreme God and in no way equal to Him. Besides, the idea of Supreme God-His omnipotence, immanence and transcendence on which Guru Nanak laid much emphasis, was not new to the Hindus of his time.

(3) Nanak did not want to destroy the Old Order :

Guru Nanak had not attempted a destruction of the old order but a reformation to suit the growing needs of the time. Like a revolutionary, he did not aim at destroying completely the prevalent institutions. Nor did he attempt to establish new institutions on their ruins. He only reformed institutions and wanted to purge them to suit the needs of the society.

(4).Nanak condemned the caste pride and not the caste system :

Guru Nanak did not denounce the caste system and the hierarchical character of the Hindu society. What he condemned were the evil practices, rites and rituals and the caste practices which were being observed by the masses without realising their true meaning. He condemned in severe terms those who instead of worshipping the True Lord were proud of their higher castes.

(5).Establishment of Sangat was not an innovation :

The establishment of Sangat by Guru Nanak was not a revolutionary step. It was not an innovation but it had its forerunner in the Buddhist Sanhita (Sangha) and the congregation of Muslims and Christians. It cannot, however, be denied that the institutions of Sangat and Langar started by Guru Nanak are the two institutions which have worked regularly and systematically since their foundation by Guru Nanak and have successfully kept the Sikh society both democratic and equalitarian.

(6).Guru Nanak belongs to the creed of Bhakti Reformers :

It is also argued that some of the tenets of Guru Nanak's creed are the same as advocated by the Hindu religious reformers of the medieval period. Guru Nanak's idea of surrender of the human will to the Divine Will was simply the repetition of the old doctrine of `parapti'. Similarly emotional worship, belief in the rigidity of the caste system, adoration of the Guru or Gurubhakti, transmigration of soul, service of God and humanity, i.e., Kain Kirya, had all been emphasised by the early Bhakti reformers, though not so systematically and strongly as by Guru Nanak. Besides, the inclusion of the hymns of most of the Hindu Bhakti reformers like Nam Dev, Kabir, Ravidas etc. in the Adigranth of the Sikhs also points to the identity of Guru Nanak's teachings with those of the Bhakti reformers.

(7).The foundation of the institution of Guruship not a revolutionary step :

Some scholars hold that the foundation of the system of Guruship by Guru Nanak was a revolutionary step which resulted in the gradual development of the Sikh community and the establishment of the Khalsa Panth. However, the institution of Guruship was not unknown before Guru Nanak. But it cannot be denied that the institution of the ten Sikh Gurus has been unique and resulted in the building up of the national and heroic spirit for which the Sikh community has become well-known.

It is thus clear that Nanak, like Buddha wished to live in peace and amity, unity and goodwill with persons of all faiths. He mainly emphasised the removal of superstitions, empty ritual practices and evils from which humanity was suffering in his time.

Second View-Guru Nanak was a Revolutionary :

Some Scholars are of the view that Guru Nanak was not a reformer like Hindu Bhakti reformers. In fact, he laid the foundation of the Sikh religion and there was substantial originality in his religious ideas and in this sense he was a revolutionary. J. S. Grewal remarks that "Nanak rejects contemporary forms of religious beliefs and practices only because he is convinced that he has something more valuable to offer. Invariably rejection is accompanied by a positive offer, the offer of one or another of his own ideals." These writers advance the following arguments in support of their view.

(1).Denounced the Caste System :

Guru Nanak vehemently condemned the caste system, the steel frame of the Hindu society and succeeded in loosening the bonds of this system. He exhorted his followers to defy the rules of caste exclusiveness. In his congregations, his disciples from all the castes and classes irrespective of the fact whether they belonged to the higher castes or the low castes, sat together. They partook food in the common kitchen or Langar. Before Nanak, some of the Hindu reformers had denounced the caste distinctions but none had taken any concrete step to defy them in such a practical manner and on such a mass scale. Thus, the open defiance, rather revolt of Guru Nanak against the most fundamental and a sacred institution of the Hindus has led the above historians to style him as a revolutionary.

(2).Condemned Asceticism-a basic feature of Hinduism :

Asceticism, fasting and penance had always been regarded as essentials of Hinduism. Guru Nanak severely condemned them and told the people that they were merely exercises. Nanak held that leaving one's home and family and living away from the people was an act of defeatism. He advised his people that if there is anything to be renounced it is evil. One can attain the grace of God even without becoming an ascetic or adopting the garb of a Faqir. He preached his followers to remain in the world but not attached to wordly things. Nanak's disapproval of asceticism is evident from- the fact that he refused to appoint Sri Chand, his elder son, as a successor, as he was an ascetic. Nanak had a revolutionary tone, and was regarded as revolutionary by all the ascetics and Jogis who came into his contact during his extensive tours.

(3).Nanak repudiated Hindu Mythology :

It is argued that Guru Nanak did not base his teachings on Hindu mythology nor did he and his followers borrow their material for their religious inspirations from the Hindu Sanskrit literature. As it was a unique step, it was, therefore, natural for some of the scholars to conclude that Guru nanak was a revolutionary.

(4).Opposed Idol Worship :

Since time immemorial, the Hindus had been worshipping the idols of Hindu gods and godesses such as Shiva and Durga in the temples with great devotion. They regarded the idols of the deities as the image of God. But Guru Nanak opposed the practice of idol worship. He preached that God is formless. He cannot be represented in any shape and it was wrong to And God in the idols. The denunciation of this basic feature of Hindu religion was definitely a revolutionary step.

(5).Denounced Hindu customs and rites as Useless :

Guru Nanak denounced rituals and practices of the Hindus Karma Marg of the Hindus is based on the theory that some action must. be performed to please God. God can be obtained by offering sacrifices. Religion had thus become a sort of ritual. Certain actions were regarded as earners of religious merit, for instance, offering water to the Sun, offering food to the ancestors fasts, visit to places of pilgrimage like Haridwar, Kurukshetra and Benares and prayers at particular times. Guru Nanak questioned the utility of these rites and ceremonies and declared that they were purposeless. He enjoined upon his followers not to perform these rituals and worship True Lord alone with devotion.

(6).Established new Institutions and Innovations :

Guru Nanak started many new institutions which were not known to the Hindu religion nor were practised by the Bhakti reformers. In the first place, Nanak introduced the Sangat System which was a revolutionary step.Nanak said that the Guru resides in the Sangat. It helped in the ripening of one's spiritual thought, and helped in the social and organisational field as well.Secondly, he started the institution of Langar or free kitchen. It was meant to feed the poor, the crippled and all the other visitors who came from far and near to see the Guru. It helped in the spread of Guru's message and strengthened the bond of unity among the votaries of Nanak.Lastly, Guru Nanak emphasised that Guru was essential for the realisation of God. It was only through him that man could discover the eternal grace of God. There was no need to worship any god or goddess. A little before his death, Guru Nanak nominated his most devoted and sincere disciple, Bhai Lehna as his successor. Guruship in Sikhism was a new status, providing a living ideal for his followers.

(7).Guru Nanak evinced interest in Politics :

Though Guru Nanak remained indifferent to the political condition of the time yet his compositions reveal his familiarity with nearly all aspects of contemporary political events. He expressed deep anguish over the conduct of the rulers and administrators of his time. At one place he remarked, "The Rajas are lions and the Muqadams are dogs, they fall upon the ryots days and night; their agents inflict wounds with jaws of power and dogs lick blood and relish the liver." Nanak thus protested against the atrocities committed by the rulers. Such feelings of Nanak led to the growth of discontentment among the people against the Mughals and aroused them to rise up in arms against the Mughal tyranny.

Conclusion :

From the study of the views of the above writers we may finally conclude that Guru Nanak was not an ordinary reformer and there was an echo of revolutionary ideas in his reforms. Gurmukh Nihal Singh remarks, "To lay the foundations of a casteless and classless society, which was egalitarian and democratic cannot but be revolutionary. It is also true that Guru Nanak was at the same time a great reformer who endeavoured to rid Indian society of many evils and superstitious practices. Guru Nanak was thus both a "revolutionary and a reformer and there is nothing unnatural or contradictory in being both. The same is true of Mahatma Gandhi in our times."