The battles over evolution, climate change, childhood vaccinations, and the causes of AIDS, alternative medicine, oil shortages, population growth, and the place of science in our country, all are reaching a fevered pitch. Many people and institutions have exerted enormous efforts to misrepresent or flatly deny demonstrable scientific reality to protect their nonscientific ideology, their power, or their bottom line. To shed light on this darkness, the author explains the scientific process and why society has come to rely on science not only to provide a better life but also to reach verifiable truths no other method can obtain. He describes how major scientific ideas that are accepted by the entire scientific community (evolution, anthropogenic global warming, vaccination, the HIV cause of AIDS, and others) have been attacked with totally unscientific arguments and methods. He argues that science deniers pose a serious threat to society, as their attempts to subvert the truth have resulted in widespread scientific ignorance, increased risk of global catastrophes, and deaths due to the spread of diseases that could have been prevented.