Basavanna, a great 12th-century Hindu philosopher and reformer

Guru  sri Basava. Lingayat Religion

Basavanna, a 12th-century Lingayat Hindu (Saivite).

philosopher, statesman, and Kannada poet  was a well-known social reformer and lived during the reign of  the Kalachuri-dynasty king Bijjala I in Karnataka, India. He focused his attention on bakthi movement and spread of social awareness by way of his devotional poems called  Vachanaas. His approach to realization of god got the attention of many people because in his philosophy there was no room for gender or social  discrimination based on birth. Nor was there any space for  unnecessary rituals, superstitions, etc that plague our society. Even he rejected the idea of wearing the sacred thread on the body. However, he encouraged his followers, irrespective of castes,  to wear a Istalinga necklace or mala with the image of Lord Shiva, one of the trinity Gods, an embodiment of 5  fundamental elements of "Nature"(Pancha Boothams).  It means the focus will be on one God Shiva.   Being the chief minister of his kingdom, he encouraged people from all walks of life to engage in  discussion on various aspects of life - religious, philosophical  and spiritual. He built the hall of spiritual experience called  the Anubhava Mantapa where people can have intellectual discussion.

Sri Basava, equestrian statue, Pune, MHquestrianstatue.org/basava-7/

Basava, also known as Basaveshwara (1134–1196) fought against caste system. In the 12th century itself, his reforms were progressive and rationalistic, hence he was a great thinker ahead of his time. Basaveshwara introduced the concept of Democracy long long ago with equal representation from women and men  and also people with different socio-economic background  from all walks of life. Basava rejected the Vedas and the authority of priests. He also opposed image worship and unwanted rituals. Most importantly, he emphasized  complete equality among his followers, including women. 

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 Above image: View of Kudala Sangama temple, the location of Basavanna’s Samadhi
His following  concepts are worthy of mention : 

01. No discrimination based on the birth and caste system is a taboo.  

02. Mercy toward all humans and animals is a must

03. The conflicts of  interest will always arise and peaceful negotiation is a way to solve them. Violence may lead us astray. 

04. Trust in God who is the creator and who is  omnipresent and Supreme power.
05.  You must When it comes to earning wealth for you and your family, it ought to be through  honest means.  Ill-gotten wealth will never stay with you.

06. If you have excess beyond your needs, be charitable and contribute liberally to  the rest to the society through Dasoha.

07. Morality is an integral part of a man's life. Aspiring for others' wealth out of jealousy and other women out of lust is not conducive to peaceful and moral life. At the end, it will spell disaster. No killing, cheating, killing, no hatred for other beings, no self adulation, etc to get inward purity. 

08. When you earn the trust of others, try to stick to it.  Never ever  act or do things in  breach of trust.

09. When following  your goal, never lose your trust. 

Basava Samadhi. Virashaiva

10. Living a principled life is a must.
11. Never fail to follow the dictum - " there is none lower than me and there is none greater than society of Sharanas.

He advocated equal opportunities for women and vegetarian food for good physical and mental well being. The 13th-century sacred Telugu text of Lingayat community, the Basava purana by Palkuriki Somanatha narrates the the full life of Basava.
The Basavarajadevara ragale by the Kannada poet Harihara (c.1180) is believed to be an important work on Basava's life. Out of 25 section, only 13  are available.  Basava is not the founder of Lingayats, rather he was a reformer and a poet who consolidated the already existing tradition. The Kalachuri inscriptions support the latter view.  Basava's  literary works include the Vachana Sahitya in Kannada Language. He is also known as Bhaktibhandari (literally, the treasurer of devotion).
His philosophy of life within the realm of Hinduism is simple, yet thought-provoking. 

https://en.wikiquote.org/wiki/Basava