Information about his life and achievements come from the many Kannada writings, the earliest of which were written just after his death. Hoysala poet Harihara's "Basavarajadevara ragale" is the first known biography on Basavanna. Vijayanagara poet-writer Bhima Kavi's "Basavapurana" (1369), Singiraja's "Amala Basavacharite" (1500), Vijayanagara minister Lakkanna Dandesa's "Shiva Tatwachintamani" (1425–1450) are some of the important sources. The cornerstone of Basavanna's philosophy was "work-worship is heaven", the rejection of mere worship of God and the acceptance of one's own body as a temple of God. Basavanna strongly advocated a life of complete commitment to work. As a poet, he finds a pride of place in Kannada literature. His deftly written poems end with the word "Kudalasangama" which literally means "God of the confluence of two rivers", the poet's version of the god Shiva. About 1,300 such poems have survived, and have been described by H.S. Shiva Prakash as lyrical, satirical, deeply contemplative and self-critical.