Thakurartha Devadithya Guardiyawasam Lindamulage Nalin Kumar de Silva (Sinhala: නලින් ද සිල්වා; 20 October 1944 – 1 May 2024) was a Sri Lankan philosopher,[2][3] polymath and a political analyst.

[5][6] In June 2011 he stated that information regarding the presence of arsenic in water claiming that the cause of Rajarata chronic kidney disease had been given to him by the god Natha.

[16] The Rajarata chronic kidney disease (RCKD) has been an ailment prevalent in the North Central Province of Sri Lanka for several decades.

[20] As this statement caused a huge uproar in the agricultural sector in Sri Lanka, the Industrial Technology Institute stated that they had used Hydride Generation Atomic Absorption Spectrometry on rice samples which showed no high levels of arsenic.

[21] The ITI study also found that in samples of 28 different pesticides only 3 showed any signs of arsenic, and even then not in the concentrations that De Silva's team alleged.

[19] The Kelaniya University team stated that they had used new methods to locate the Arsenic in the samples they collected but did not feel a need to submit their findings for peer-review.

[22] De Silva stated that they did not publish their results in a "so-called peer reviewed journal due to our concern regarding the authorship of the paper as the original idea was given by 'samyak drshtika devivaru' also known as Devas.

[23] When the authenticity of the findings made by the University of Kelaniya team were questioned by other scientists, De Silva stated that the god "Natha" had first told them about the arsenic through a mystic.

She said that they had first been told of the arsenic by the wife of "a university lecturer who had developed her mental faculties to communicate with a higher being", but then used scientific methods to deduce it.

[25] The Sri Lanka Association for the Advancement of Science released a statement in July 2011 questioning the validity of the findings and the process and individuals involved in the study.

While recognising that many scientists are deeply religious, the SLAAS wishes to state categorically that superstition and the supernatural have no place in science, and that scientific results inspired by such sources are highly suspect because of a probable bias on the part of the investigator.

[26]De Silva, who was influenced by Paul Feyerabend, rejected the existence of scientific method and proposed proliferation of sciences on various chinthanayas.

When I was in the University of Colombo, not the best place to fight the cultural pentagon, I was asked by the then Vice Chancellor G. L. Peiris why I was teaching Jathika Chinthanaya to a captive audience.

[30] In 2008 the Veemansaka Parshadaya, a student organisation where De Silva is the treasurer and mentor started a campaign to ban western clothing in Kelaniya University.