The Demon-Haunted World: Science as a Candle in the Dark is a book by Carl Sagan intended to explain the scientific method to laymen, and to encourage people to learn critical or skeptical thinking. It explains methods to help distinguish between ideas that are considered valid science, and ideas that can be considered pseudoscience. Sagan states that when new ideas are offered for consideration, they should be tested by means of skeptical thinking, and should stand up to rigorous questioning.
Sagan said if a new idea continues in existence after an examination of the propositions, it should then be acknowledged as a supposition. Skeptical thinking essentially is a means to construct, understand, reason, and recognize valid and invalid arguments. Wherever possible, there must be independent validation of the concepts whose truth should be proved. He believed that reason and logic would succeed once the truth is known. Conclusions emerge from premises, and the acceptability of the premises should not be discounted or accepted because of bias.
Sagan presents a set of tools for skeptical thinking which he calls the "baloney detection kit". Skeptical thinking consists both of constructing a reasoned argument and recognizing a fallacious or fraudulent one. In order to identify a fallacious argument, Sagan suggests the employment of such tools as independent confirmation of facts, quantification and the use of Occam's razor. Sagan's "baloney detection kit" also provided tools for detecting "the most common fallacies of logic and rhetoric", such as argument from authority and statistics of small numbers.
Through these tools, the benefits of a critical mind and the self-correcting nature of science can take place. Sagan provides a skeptical analysis of several kinds of superstition, fraud, pseudoscience and religious beliefs, such as gods, witches, UFOs, ESP and faith healing.
A remembrance of Carl Sagan, astronomer, writer, and national teacher of science. Here is how he introduced his 1980 public television series "Cosmos. " CARL SAGAN: ("Cosmos" 1980) The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home, the Earth. For the first time we have the power to decide the fate of our planet and ourselves. This is a time of great danger, but our species is young and curious and brave. It shows much promise. In the last few millennia we have made almost astonishing and unexpected discoveries about the cosmos and our place within it. I believe our future depends powerfully on well we understand this cosmos in which we float like a mode of dust in the morning sky.
We're about to begin a journey through the cosmos. We'll encounter galaxies and suns and planets, life and consciousness coming into being, evolving, and perishing, worlds of ice and stars of diamond, atoms as massive as suns and universes smaller than atoms. But it's also a story of our own planet, and the plants and animals that share it with us, and it's a story about us, how we achieved our present understanding of the cosmos, how the cosmos has shaped our evolution and our culture and what our fate may be. We wish to pursue the truth no matter where it leads, but to find the truth, we need imagination and skepticism both. We will not be afraid to speculate, but we will be careful to distinguish speculation from fact. The cosmos is full beyond measure of elegant truths, of exquisite inter-relationships, of the awesome machinery of nature.
The surface of the Earth is the shore of the cosmic ocean. On this shore we've learned most of what we know. Recently, we've waded a little way out, maybe ankle-deep, and the water seems inviting. Some part of our being knows this is where we came from. We long to return. And we can't, because the cosmos is also within us. We're "made" of star stuff. We are a way that the cosmos can know itself. The journey for each of us begins here. We're going to explore the cosmos in a ship of the imagination, unfettered by ordinary limits on speed and size, drawn by the music of cosmic harmonies. It can take us anywhere in space and time. Perfect as a snowflake, organic as a dandelion seed, it will carry us to worlds of dreams and worlds of facts. Come with me.
