Skepticism, in the sense that we use the word, is an approach of critical inquiry. It does not claim that we can know nothing. Nor is it opposed to belief. We all have and need beliefs to get through life.

But modern skepticism demands that we question what we are asked to believe or to practice. It demands we base our beliefs and practices on the best available evidence, and be prepared to give these up when they are shown to be unsupported or are surpassed by better supported alternatives. In short, it considers the world scientifically.

Critical inquiry can be applied to all matters of life from the most mundane (what brand of detergent should I buy?) to the most profound (is there a purpose to life?). In practice however the skeptical movement has focused on paranormal claims and pseudoscience. This is what modern skeptics have become best known for dealing with.

To get an idea of what modern skepticism is about, let’s look at some of the interesting issues skeptics have addressed. The subjects that skeptics have investigated can be divided into two main groups:

A. PARANORMAL BELIEFS AND PRACTICES

Paranormal means “beside the normal” or “parallel to the normal reality”. It includes phenomena that are supposedly supernatural and are held to be unexplained by science — sometimes even unexplainable by science. Examples, in no particular order:

Ghosts • Astrology • Fortune telling • Psychics • Faith healing • Dowsing • Communication with the dead • Crystals • Spoon bending • Channelling • Past lives • UFOs • Alien abductions • Clairvoyance • Auras • Telekinesis • Bermuda Triangle • Weeping statues • Shroud of Turin • Nostradamus • Near-death experiences • Astral projection • Pyramid Power • Bible Code • Effect of the full moon • Prophecies • Tarot cards • Psychic detectives • Mediums • I Ching • Fairies • Atlantis • Palm reading • Crop circles • Psychic surgery….

B. PSEUDOSCIENCE

“Pseudo” means fake, so this category is about fake science — things that have been given an aura of scientific legitimacy but nonetheless are unscientific, illogical, or not supported by the evidence:

Parapsychology • Homeopathy • Naturopathy • Iridology • Creationism • Cryptozoology (Bigfoot, Sasquatch, Nessie) • Recovered memory • Facilitated communication • Chiropractic • Aromatherapy • Velikovsky • Perpetual motion machines • Graphology • Ancient astronauts • Spontaneous human combustion • Biorhythms • Iridology • Therapeutic touch • Face on Mars • Moon landing myth • Reflexology….

Some of these items, such as UFO claims and Nessie sightings, can straddle both categories, depending on how they are being put forward. Some UFO buffs, for example, claim that the unidentified flying objects are extraterrestrials visiting earth in spaceships, which may be a dubious claim but is at least scientifically possible and empirically verifiable, while others hold that UFOs are psychic manifestations, which puts them in the paranormal camp.

Then there are some things that do not easily fall into either the paranormal or pseudoscience camp.

C. GREY AREAS

In this miscellaneous category we can lump phenomena that are not necessarily paranormal or pseudoscientific but have been scrutinized by skeptics, as well as issues about which skeptics as a group are undecided whether they should come under scientific examination. Examples:

New science • Religious claims • Cults • Hypnosis • Assassination conspiracies • Psychoanalysis • Psychotherapeutic drugs • Political claims • Effects of prayer • Holocaust denial • Racism • Cold fusion • Placebo effects • Life after death • Morality….

According to some skeptics, such as myself, every belief or practice faced by human beings can and should be subjected to critical scrutiny. Other skeptics make exceptions for experiences that they consider outside the empirical sphere, such as religious experiences or moral questions.

In either case, we generally restrict our inquiry to claims that are testable. It is difficult to see, for example, how we could test the hypothesis that a Supreme Being exists, although we can certainly examine evidence that is put forward to support the claims for the existence of a god.

Whether or not we can find conclusive evidence for or against all claims, we can at least seek whatever evidence is available to help inform our decision making. That’s the skeptical approach.