The evidential argument from evil is valid.

The presence of gratuitous natural evils makes the existence of a theistic God (i.e., an omniscient, omnipotent, and omnibenevolent God) highly improbable. For starters, it seems pertinent to point out that this argument should not be confused with the logical version of the argument from evil. Although the existence of vast amounts of natural evil may be logically compatible with God's existence, they are, nonetheless, capable of lowering the probability of God's existence. This assertion is supported by the proposition that the suffering resultant from animal predation and natural selection is much better explained by naturalism than theism. In other words, the indifference of the natural world is much better reconciled with heinous evils than any theistic hypothesis could ever hope to be. To borrow a phrase from the philosophy of science, naturalism can be viewed in this context as the proper "inference to the best explanation". [1] When this argument is properly understood, it helps illustrate the fundamental superiority of the purely scientific worldview to its counterfeits. =============> The Case Against God: Naturalism, Evil, And The Disconfirmation of Theism <============ C1: Naturalism is far more plausible than theism. The predictive power of metaphysical naturalism to account for natural evils makes atheism objectively more likely to be true than theism. Consider, for instance, the clumsiness with which evolution has assembled all living organisms. The development of life on Earth was engineered by natural selection – a mechanism that has left 99.9 percent of all of the species that have ever lived on Earth extinct. [2] Moreover, biological evolution is also a process that does not (and cannot) distinguish between the survival of conscious organisms and mindless viruses. As such, viruses and numerous deadly pathogens have often run roughshod over the desires and goals of sentient creatures. In the 20th century alone, smallpox killed over 500,000,000 people, many of them children. [3] Likewise, the struggle for survival in nature guarantees that most animals (human and nonhuman) will suffer horribly as they get outcompeted for resources and die from lack of sustenance or from being eaten. Aut vincere aut mori (Either conquer or die) - such is the dictum guiding nature's mindless directive to life. In a very real way, evolution is advanced by the grinding of teeth upon bone. As a result of this, nature has guaranteed that many animals, including humans, will never be able to flourish and often die in great agony. Given the existence of natural evils and their dependence on physical laws, it becomes possible to assemble a logical syllogism to demonstrate the truth of the key points outlined so far. The American philosopher Paul Draper, who teaches at Purdue University, has made such an argument. Unlike many past arguments from evil, his particular argument relies on an inductive move to arrive at the conclusion. And he bases his argument on the following evidence statement: E: For a variety of biological and ecological reasons, organisms compete for survival, with some having an advantage in the struggle for survival over others; as a result, many organisms, including many sentient beings, never flourish because they die before maturity, many others barely survive but languish for most or all of their lives, and those that reach maturity and flourish for much of their lives usually languish in old age; in the case of human beings and some nonhuman animals as well, languishing often involves intense or prolonged suffering. P1: We know that E is true. P2: Naturalism has much more predictive power with respect to E than theism does (i.e., E's truth is antecedently many times more probable given naturalism than it is given theism). P3: Naturalism is more plausible than theism (i.e., naturalism is more probable than theism independent of all evidence). C: So, other evidence held equal, theism is very probably false. (Draper [4]) Of course, some theists will still be skeptical of the proposition that naturalism really does have more predictive power in accounting for natural evils than theism does. However, as Draper has indicated, there are good reasons to be surprised by natural evils like smallpox epidemics given the truth of theism that are not present under a naturalistic hypothesis. Moreover, there are very good reasons to expect that natural evils will occur if naturalism is true, which are not present given theism. To set the groundwork, almost all sentient creatures can flourish, which is a necessary component of achieving the good life; and if a theistic God existed, he, in his moral perfection, could not possibly care more about the well-being of his creation in order to let them flourish. And given God's complete power and knowledge, he could also not possibly be in a better position to ensure that sentient beings achieve the good life. As such, vast amounts of natural evil that prevent many animals from flourishing is implausible under theism. Conversely, natural evils are very much to be expected under naturalism. Evolution, which is guided by natural selection, predicts that many animals will languish and die in the struggle for survival. Without supernatural intervention, gratuitous amounts of suffering are guaranteed, making natural evils many times more probable under naturalism than theism. Furthermore, the second premise of Draper's argument is very well supported for another reason. Naturalism is a simpler hypothesis than theism by its very nature, and it also has a comparable scope to theism (and likely a much smaller scope than theism). Simply put, theism's a priori commitment to the necessary existence of highly specific supernatural entities like God makes it more likely to be erroneous than naturalism, which posits no such entities. And for the purpose of this argument, it is of primary importance to indicate that simple explanations are inherently more plausible than complex explanations. The Oxford philosopher Richard Swinburne puts it this way, "[All] other things being equal—the simplest hypothesis proposed as an explanation of phenomena is more likely to be the true one than is any other available hypothesis, ... its predictions are more likely to be true than those of any other available hypothesis, and ... it is an ultimate a priori epistemic principle that simplicity is evidence for truth." [5] Thus, all things being equal, naturalism is a much better and more parsimonious hypothesis than theism. ::Conclusion:: In summary, the paucity of evidence for theism and the strong evidential grounds for atheism make the God hypothesis completely untenable. As was demonstrated earlier, naturalism has more predictive power than theism in accounting for evils that can be found in nature. Consequently, the occurrence of natural evil makes it reasonable to seriously doubt the existence of God. There are simply so many natural evils in the world that it is only reasonable to recognize that naturalism is a far more parsimonious and logical explanation than theism in accounting for them. Therefore, on balance, the weight of the evidence leans heavily in favor of the proposition that God doesn't exist. Sources: 1. W.H. Newton-Smith (ed) A Companion to the Philosophy of Science (Blackwell, 2000) pp. 184-193. http://tinyurl.com... 2. Newman, Mark, and Bruce Roberts. "Mass Extinction." Cornell Laboratory of Atomic and Solid State Physics. 20 May 1994. Web. 12 Nov. 2010. http://tinyurl.com... 3. Harris, Sam. Letter to a Christian Nation. New York: Knopf (2006) p. 54 4. Draper, Paul. "Great Debate Footer." Secular Web: Atheism, Agnosticism, Naturalism, Skepticism and Secularism. 2007. Web. 12 Nov. 2010. http://tinyurl.com... 5. Swinburne, R. Simplicity as Evidence for Truth, Milwaukee: Marquette University Press. (1997) p. 1