Natural evil, or surd evil, is a term generally used in discussions of the problem of evil and theodicy that refers to states of affairs which, considered in themselves, are to be avoided and not to be promoted, and for which no agent is morally responsible. It stands in contrast to moral evil.

Moral evil results from a perpetrator, or one who acts intentionally and in so doing has flouted some duty or engaged in some vice. Natural evil has only victims, and is generally taken to be the result of natural processes. The "evil" thus identified is evil only from the perspective of those affected and who perceive it as an affliction. Examples include cancer, birth defects, tornadoes, earthquakes, tsunamis, hurricanes, acts of god, and other phenomena which inflict suffering with apparently no accompanying mitigating good. Such phenomena inflict "evil" on victims, but with no human perpetrator to blame for it.

Jean Jacques Rousseau responded to Voltaire's criticism of the optimists by pointing out that the value judgement required in order to declare the 1755 Lisbon earthquake a natural evil ignored the fact that the human endeavour of the construction and organization of the city of Lisbon was also to blame for the horrors recounted as they had contributed to the level of suffering. It was, after all, the collapsing buildings, the fires, and the close human confinement that led to much of the death.

R. William Hasker is an American Christian philosopher and Distinguished Professor Emeritus of philosophy at Huntington University. For many years he was editor of the prestigious journal Faith and Philosophy. He has published many journal articles and books dealing with issues such as the mind-body problem, theodicy, and divine omniscience. He has affirmed "Open Theism" and a view known as "emergentism" regarding the nature of the human person. Hasker regards the soul as an "emergent" substance, dependent upon the body for its existence.

Hasker received his Ph.D. in theology and philosophy of religion from The University of Edinburgh. His 1999 publication The Emergent Self discusses the philosophy of mind and attempts to establish that mind cannot be solely a material process but is also not completely distinct from its physical basis in the brain.

Hasker has published numerous works. A selection:

Frederick Antony Ravi Kumar Zacharias (born 1946) is an Indian-born, Canadian-American evangelical Christian apologist. Zacharias is the author of numerous Christian books, including Gold Medallion Book Award winner Can Man Live Without God? and bestsellers Light in the Shadow of Jihad and The Grand Weaver. He is the founder and chairman of the board of Ravi Zacharias International Ministries, host of the radio programs Let My People Think and Just Thinking, and visiting professor at Wycliffe Hall of Oxford, where he teaches apologetics and evangelism. Zacharias studied as a visiting scholar at Cambridge University and held the chair in Evangelism and Contemporary Thought at Alliance Theological Seminary from 1981 to 1984. Commentator Chuck Colson referred to Zacharias as "the great apologist of our time."

Zacharias was born in Madras, India. Zacharias claims descent from a woman (of the Nambudiri Brahmin caste) and a low caste Boatman. Missionaries spoke to one of his ancestors about Christianity and thereafter the family was converted. Zacharias grew up in a nominal Anglican household, and he himself was an atheist until the age of 17, when he unsuccessfully tried to commit suicide by swallowing poison. While in the hospital, a local Christian worker brought him a Bible and instructed his mother to read to him out of John 14. Zacharias says that it was John 14:19 that touched him and caused him to commit his life to Christ.

Colin McGinn (born March 10, 1950) is a British philosopher currently working at the University of Miami. McGinn has also held major teaching positions at Oxford University and Rutgers University. He is best known for his work in the philosophy of mind, though he has written on topics across the breadth of modern philosophy. Chief among his works intended for a general audience is the intellectual memoir The Making of a Philosopher: My Journey Through Twentieth-Century Philosophy (2002).

Colin McGinn was born in the town of West Hartlepool, England in 1950. He enrolled in Manchester University to study psychology. However, by the time he received his degree in psychology from Manchester in 1971 (by writing a thesis focusing on the ideas of Noam Chomsky), he wanted to study philosophy as a postgraduate. By 1972, McGinn was admitted into Oxford University's Bachelor of Letters postgraduate programme, in hopes of eventually gaining entrance into Oxford's postgraduate Bachelor of Philosophy programme.

David A. Kyle (born February 14, 1919) is a Potsdam, New York-based science fiction writer and prominent member of science fiction fandom.

With Martin Greenberg, Kyle founded Gnome Press in 1948. He has written two pictorial histories of science fiction (A Pictorial History of Science Fiction and The Illustrated Book of Science Fiction Ideas and Dreams) and three licensed novels set in the Lensman universe (The Dragon Lensman, Lensman from Rigel and Z-Lensman).

He appeared with Paul Levinson, Greg Bear and many others on the History Channel's 2002 documentary, Fantastic Voyage: Evolution of Science Fiction.

Kyle, an active fan since the earliest days of organized science fiction fandom, was an original member of New York's Futurians.

He attended the first Worldcon, and both wrote and printed the "Yellow Pamphlet" condemning the organizers. The manifesto led chairman Sam Moskowitz to ban several prominent members of the Futurians from that convention.

Kyle chaired the 1956 14th World Science Fiction Convention (NyCon II), inspiring the fan catchphrase, "Dave Kyle says you can't sit here." He was created a Knight of The Order of Saint Fantony in 1961, and was awarded the Big Heart Award in 1973. Kyle was also Fan Guest of Honor at ConStellation, the 41st World Science Fiction Convention, in 1983.