The split in the Indian National Congress at Surat in 1907 was primarily due to the increasing ideological rift between the Moderates and Extremists regarding their approach to British rule. The Extremists, led by leaders like Bal Gangadhar Tilak, believed that the Moderates' methods of negotiation and reform were ineffective in securing Indian interests, leading them to advocate for more direct action and nationalistic fervor. This schism highlighted a broader struggle within the Indian independence movement over the most effective strategy to attain political rights and self-governance, an important theme in the historical evolution of Indian nationalism.