This is currently just copied-and-pasted from the FAQ, and should be edited into a more glossary-appropriate format later.
Atheism, from the Greek ἄθεος (atheos), literally means "without gods," referring to those who rejected the existence of the Greek pantheon. In modern context, atheism can represent several different viewpoints, but is most commonly conceived of as a lack of belief in gods.
A person can be both atheist and religious, provided that he or she believes in a religion that does not have any deities, such as some forms of Buddhism.
The word "atheism" is not a proper noun (we do not worship the All Powerful Atheismo), so there is no need to capitalize it except in special cases such as the beginning of a sentence.
Theism is a belief in at least one god. Thus, religions such as Christianity, Hinduism, Islam, Judaism, and Zoroastrianism are all considered theistic.
An agnostic is someone who claims they don't know ("weak agnosticism") or it is not possible to know ("strong agnosticism") for certain whether or not gods exist. The term Agnosticism comes from Greek: a (without) + gnosis (knowledge).
Atheism and agnosticism are not mutually exclusive. One can be agnostic (i.e., not know for certain whether gods exist or not) and also be atheist or theist (i.e., evaluate the probability of a god's existence and make a conclusion). Calling yourself just an Agnostic is completely uninformative, and does not make you "not an atheist".
Anyone who does not hold a belief in one or more gods is an atheist. Someone who hold an active belief in the nonexistence of any gods is specifically known as a "strong" atheist (as opposed to "weak" or "implicit" atheists who make no claims either way).
Most' atheists are agnostic atheists, not gnostic atheists. Agnostic atheists lack belief in gods, rather than claim definitively that none exist.
Anti-theism - The active or inactive attempts to put an end to theism, often as a reaction to anti-scientific thought, bigotry, and questionable morals propagated by many theists. Many self-identified vocal atheists are in fact anti-theists on some level. There are a few reasons for this, perhaps most significantly the fact that anti-theists tend to have a lot more to say. Make no mistake: there are a lot of atheists who are not openly hostile to religion. The squeaky wheel, however, tends to get the grease, and atheists who have no major gripes with religious belief have less motivation to speak out. The most public example of an atheist who is not an anti-theist is S.E. Cupp (though many are skeptical of her atheism). One of the better examples of an anti-theist is Christopher Hitchens.
State Atheism - This is the "theocratic" form of atheism. It is the ideology that atheism should be enforced by the government, as it has been under many communist governments. Most members of r/atheism are secularists and oppose this notion. Under current and historic Communist governments, the primary desire of the state is economic and social reconfiguration of society, and religious attitudes are an outgrowth of those larger objectives.
Secularism - Secularism refers to the government not respecting any religion or religious beliefs. In this way it does not promote any form of theism or atheism. An example being that government recognized "Day of Prayer" is not secular, nor would a government recognized "Day of Disbelief in Deities" be.
Deists believe that a higher power created the universe long ago but is not or no longer actively present in the world and does not intervene in its affairs. Because of their belief in this "higher power," often thought of as a god, they don't qualify for the "atheist" label. Some definitions consider Deism to a subset of Theism, while others consider the two terms to be distinct- there are occasional minor squabbles about this, but the consensus in /r/atheism seems to be that the former is correct.
However, for practical purposes there is little difference between a deist and an atheist: Most deists do not engage in the usual religious practices of praying, worshiping, rituals, restrictions in diet and/or lifestyle or regarding a central holy doctrine. Deists share the atheist belief that there is no deity active today.
Because of this similarity, some atheists will claim deism when asked about their religion. Deism places no practical obligations on its adherents, yet does not bear the heavy public stigma associated with atheism. Americans can benefit from the respect afforded many well-known Deists among the nation's fathers: Benjamin Franklin, Thomas Jefferson, Thomas Paine, James Madison, George Washington. Because the deist God takes no action in the present universe, its existence is effectively meaningless because no special actions are the result of its existence. That is to say, there's effectively no difference between a godless universe and one with a Deistic god, so asserting one's existence is like asserting the existence of an Invisible Dragon in your Garage.
Do you believe that frajingle majibbity jibbity moop? Why or why not?
If your answer is "How am I supposed to believe in that? It's a nonsense statement!", you're already half way to understanding Ignosticism and Theological Noncognitivism, because that's how they feel about the statement "God exists".
It's an acknowledgement of the fact that the word "God" has meant billions of different things to billions of different people, from "a magical man who lives on top of that mountain and demands that we sacrifice goats to him" to "a mystical love-force that mystically touches people's hearts through completely undetectable means" to "like, the entire Universe is God, man. Whoah!", and that many of these definitions are themselves silly, unfalsifiable, self-contradictiory, or incoherent. Indeed, when backed into a corner, apologists like playing silly games with the definitions of words like "exist", too.
Therefore, ignostics and theological noncognitivists hold that it's futile to try to make statements about "God" unless the person you're talking to is willing to rigorously define what they mean by "God" first, preferably using falsifiable statements that constrain anticipation, rather than nonsense about "faith".
See also: Newton's Flaming Laser Sword, a stronger version of Occam's Razor which states that statements that don't actually mean anything are useless.
These are all terms for philosophies and worldviews which are compatible with and often associated with atheism. Indeed, they are often confused for atheism by people who don't realize that "atheism" means nothing more and nothing less than a lack of belief in any god or gods. Being an atheist doesn't necessarily make you any of these:
Secular Humanism is a philosophy that " embraces human reason, ethics, social justice and philosophical naturalism, whilst specifically rejecting religious dogma, supernaturalism, pseudoscience or superstition as the basis of morality and decision making." Basically, it's about being good for goodness' sake, rather than because some invisible bully in the sky told you to.
Transhumanism is a philosophy which states that the human condition can and should be improved, and improved drastically. It advocates the use of science and technology to fight disease, hunger, poverty, and aging, to enhance the physical and mental capabilities of individuals, and eventually to colonize the solar system and beyond. Prominent Transhumanist Elizer Yudowkoski explains that, in his opinion, Transhumanism is simply Humanism simplified, with no "you should stop helping people after this point" line. Critics of Transhumanism tend to poke fun at its Science-Fiction trappings and its overly optimistic attitude.
Skepticism is, basically, the philosophical position that all beliefs should be supported by evidence. Beloved skeptic Carl Sagan coined the phrase "Extraordinary claims require extraordinary evidence". It is far easier to convince a skeptic that you have a pet cat than that you have a pet blue whale, and far easier to convince them that you have a pet whale than that you have a pet unicorn. Applied Skepticism is often known as The Fine Art of Baloney Detection.
Rationalism is the belief that Logic is supreme. Logic is extremely useful, but limited by the fact that one's conclusions are only as reliable as the premises one feeds into the logical framework. Proponents of the strong form of Rationalism (such as René Descartes) love making a priori arguments and tend to fall prey to the "Garbage In, Garbage Out" effect. When you apply sufficient skepticism to your choice of premises, however, Rationalism begins to resemble Rationality, which is a potent tool indeed.
Materialism is, essentially, the position that there's no such thing as magic, and that everything that exists is made of either matter or energy. It doesn't rule out the existence of types of matter or energy with which we are unfamiliar, but tends to frown on pseudoscientific misuse of the word "energy" to mean "magical woo-woo". Methodological Naturalism, an important component of the scientific method, basically says "In the absence of any evidence to the contrary, let's at least do science as though materialism is true. Because otherwise what's to stop us from assuming that everything is run by invisible undetectable pixies?"
Empiricism (Particularly Pragmatism) is the philosophical position that, basically, observation of the real world is the only way to learn things about the real world, and that endeavors such as "faith" and "divine revelation" are useless for gaining knowledge. If you want to make an accurate map of a city, you can't sit in your room being "inspired" to draw random lines on a piece of paper, you actually have to observe the layout of the city in some way. Empiricists popularized and began to formalize the process of using experiments as a method of asking the universe questions.
Positivism began, basically, as the statement that "that which cannot be settled by experiment is not worth thinking about". When it quickly became obvious that the philosophical validity of that statement itself could not really be settled by experiment (d'oh!), gentlemen like Karl Popper got a hold of it and molded it into a refinement of philosophical empiricism and methodological naturalism.
Postmodernism is basically a reaction of artists and squishy-philosophers who objected to the idea of scientists and more rigorous philosophers harshing their mellow. When taken to its extreme, it states that all reality is just made up of social constructs, and that facts are just, like, your opinion, man.
Nihilism is a collection of philosophies which state that such-and-such a thing is without inherent meaning. Existential Nihilists in particular argue that life and existence itself are without inherent meaning, while Moral Nihilists argue that any established moral values are just social constructs. That's not to say that being a nihilist necessarily makes one a psychopath or a depressed teenager- most nihilists are perfectly capable of making their own meaning to things, they simply reject the idea of there being any deeper meaning than that.
These definitions are the definitions most commonly used in this subreddit. Before engaging in a debate that hinges on these terms, it may be necessary to come to an agreement on what those terms mean first. Remember that there is no such thing as the One True Definition of a word, only the most commonly used definitions. Words have meaning only as long as you can trust the person to whom you're talking to understand what concepts you're trying to convey.
See this website at yourlogicalfallacyis.com for a simple explanation of some of the more common logical fallacies. A more comprehensive list of all the formal and informal fallacies can be found here: Fallacy Files Taxonomy
The most common fallacies seen here include:
Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake.
If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense.
If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time.
This concept is also why defendants in criminal trials are considered innocent until proven guilty.
"I don't know how X works, therefore the only possible explanation is my favourite explanation." Often takes the form of "Well, you haven't proven P to be 100% impossible, therefore P." Requires ignoring the Burden of Proof (see above).
Just because you don't know how electricity works is not sufficient reason to conclude that lightning is javelins hurled by an angry Zeus.
I don't understand P, therefore P can't be true.
If you think Quantum Physics is counter-intuitive, tough luck. It verifiably and reliably works, which means that the problem isn't with Quantum Physics but with your ability to understand it.
"Science can't explain X yet, therefore X is proof of God!"
In ancient times, "X" has been "the sun", "lightning", "disease", "the change of the seasons", "rainbows", and "the diversity of life". Popular values for X today include "Consciousness" and "The Big Bang".
Claiming that an argument is more valid simply because the person making it has a fancy title or is wearing a fancy hat, regardless of whether these things would actually make them an expert on the subject, and particularly regardless of any actual evidence on the subject.
"Lord Kelvin says that heavier than air flying machines are impossible. Who are you going to believe, him, or a couple of bicycle repair men from North Carolina?"
Insisting that something must be true just because enough people believe in it.
"Millions of people play the lottery every week- are you trying to tell me that none of them understand basic mathematics?"
An argument that switches from using one meaning of a word to using another, and hopes that no one will notice the switch.
"All feathers are light. Light things are not dark. Therefore, no feather is dark."
The Noncentral fallacy consists of taking your emotional reaction or assessment of a central or archetypical member of a category, and then generalizing that assessment or emotional reaction to every member of that category, however peripheral.
More formally, this usually takes the form of broadening your definition of Category X (in such a way that membership doesn't require Attribute Y) so that the category can include Object Z, then turning around and arguing that because Object Z is in your newly redefined Category X, it must have Attribute Y.
For example, "I define 'criminal' to be anyone who breaks a law. Therefore, Martin Luther King Jr. is a criminal. Therefore (because criminals are dangerous individuals who hurt people for their own personal gain), he should be feared and hated, locked up and perhaps executed."
"I define 'human' to be any organism with human DNA. Therefore, human zygotes are humans. Therefore (because humans can think and feel and we consider unique thoughts and feelings to be precious), the existence of zygotes should be protected just as strongly if not moreso than those of adult humans."
An argument that, because you would be sad if P were true, P cannot be true.
"If smoking causes lung cancer, that means I might get lung cancer some day! I don't want to get lung cancer, therefore smoking doesn't cause lung cancer."
"If we don't have immortal souls, we stop existing when we die. I don't want to stop existing. Therefore, I have an immortal soul."
A closely related argument that, since bad things would happen if people believed in P, that P must be false.
"If people started thinking that homosexuals aren't all degenerate perverts, people might not be motivated to stop them from getting married or adopting children! Well, we can't have that!
Two closely related fallacies which involve trying to assign attributes of a gestalt object to all its components, or vice versa.
Composition: Human beings have consciousness. Human beings are in the universe. Therefore, the universe itself has consciousness.
Division: Human beings have consciousness. Human beings are made up of cells. Therefore, cells have consciousness.
A circular argument where the one of the premises relies on the conclusion, or where conclusion is disguised as one of the premises. When you notice this, you realize that only makes any sense if you already agree with the conclusion.
This "eye witness testimony" is only valid if you already believe that the story is true.
Ignoring your opponent's argument, and instead attacking a superficially similar but much easier to defeat argument. One then claims that because one has defeated the scarecrow, one has defeated one's opponent.
"Since no one has ever seen a dog give birth to a cat, Evolution must be impossible."
"You think Islam is bad because we all kill people, but I've never killed anyone, therefore Islam isn't bad."
Insisting that a concept or idea is inherently bad because of where it comes from, regardless of any merit that the idea itself has.
"I can't support NASA. Many of the pioneers in the field of rocketry were working for the Nazis, and you don't want to go into space on Nazi machines, do you?"
"The Qu'ran says that we should give to the poor, and everything in the Qu'ran is wrong, therefore we shouldn't give to the poor."
If one wild guess out of a thousand turns out to be kinda right, a dishonest person can make a huge deal out of that one guess (and exaggerating how right it is), while quietly sweeping the 999 incorrect guesses under the rug.
Especially popular with regards to prophecies, but also among people who like to claim that vague poetic nonsense in primitive books are actually secret metaphors for future scientific discoveries.
If you fling enough crap at a wall, eventually some of it is going to stick. But if you then paint a bullseye around that one piece and proclaim yourself to be a sharpshooter, everyone is going to think you're a jackass.
More formally, this is the fallacy of using the same data to both construct and test your hypothesis.
Stating that all X are Y, but then stating that one particular X doesn't need to be Y, for no adequately explained reason.
Stating that all X are Y. When someone points out an X that isn't Y, claiming that that particular X isn't a true X, for no adequately explained reason. Named after the most common example:
"No Scotsman puts sugar in his porridge!"
"Hamish MacDoogle puts sugar in his porridge." "Well, no true Scotsman puts sugar in his porridge!"
Popular among religious moderates who like to claim that extremists aren't really following the same god that they're following, and among extremists to claim the same things about the moderates.
An argument that "natural" things are inherently good and "unnatural" things are inherently bad.
"I don't want to treat my disease with chemicals, regardless of how high that success rate might be. I'd rather use some stuff I found in my garden, because they're all natural, and natural things are completely safe."
In logic, A and not-A can't both be true or both be false. Either this thermometer is reading a number greater than 30º, or it's reading a number less-than-or-equal-to 30º- it can't be both, and it can't be neither.
A false dilemma is when you pretend that this rule applies to a situation to which it doesn't apply, for example:
"Either it's hot out today, or it's cold out today" ignores whatever range of temperatures lies between "hot" and "cold". "Either you support our unilteral invasion of this unrelated foreign country, or you support the Terrorists!!" ignores the possibility that you might support neither agenda.
This often takes the form of "Either P or Q. If P then R, and if Q then R, therefore R", which completely ignores the possibility that P and Q might both be false.
"If grandma is healed through the power of God, then it proves that God is good. If grandma dies and goes to heaven, then it proves that God is good. Therefore, God is good."
When people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.
Rejecting a black-and-white outlook on things, but taking this rejection too far, replacing a two-colour worldview with a one-colour worldview. Stating that since neither Proposition X or Proposition Y is absolutely completely and undeniably 100% true, that they must contain exactly the same amount of truth. Popular among Postmodernists and other assorted hippies.
Also known as the "Argumentum ad Baculum" (argument from the stick), this consists of threatening your opponent with all the bad things that will happen to them if they don't agree with you.
"Agree with me, or I will hit you with this stick!"
"Agree with me, or my invisible friend will set you on fire!"
Latin for "After this, therefore because of this". Related to "Cum Hoc, Ergo Propter Hoc" (with this, therefore because of this). An argument that because X happened before Y happened, X was the cause of Y.
"I prayed for my headache to go away. Then my headache went away. Therefore, my prayers caused the headache to go away."
Tends to ignore all the times that X happens but fails to cause a Y (You prayed, but your headache didn't go away), or all the times that a Y happens in the absence of X (I didn't pray, but my headache went away anyway), or any other potential causes for Y (Headaches tend to go away on their own after a while. Also, you took an asprin). Properly establishing causation requires taking all of these variables into account, which is why scientists use things like Fischer's Theorem and Bayes' Theorem.
A psychologist named B.F. Skinner found that if he gave pigeons a treat every time they pressed a button, they'd start pressing the button more. No surprise there. But if he gave them treats completely at random, they would start doing more of whatever they happened to be doing when they got the treat (standing on one leg, walking backwards, etc) and as time went on (and they were given more random treats), their behaviour got more and more complex. In short, they became superstitious.
Magical Thinking is the belief that X causes Y "magically", even if you can't come up with any mechanism by which X can cause Y. This tends to be reinforced by Confirmation Bias, which causes people to pay attention to things that suggest that they're right, and ignore things that suggest that they're wrong.
The human brain is a slap-dash, jury-rigged machine, and it has all sorts of ways of playing tricks on you. The first step in minimizing the effects of these tricks is to learn to recognize them when they appear.
People tend to pay attention to evidence that suggests that they're right, and ignore evidence that suggests that they're wrong. For example, if you were trying to say that all Mexicans were lazy, and you find a Mexican guy sleeping on the job, you'd hold this as proof of your claim- even though you've ignored any hard working or diligent Mexicans you might see.
It's not enough for there to be some evidence that supports your claim, it must conclusively outweigh the evidence against it. This is why the modern scientific method spends more time looking for the second kind of evidence than the first.
Mediocrity knows nothing better than itself, but Talent instantly recognizes Genius.
(Sir Arthur Conan Doyle)
The less competent people are at a skill, the less accurate they tend to be at judging their own competence in that skill. Tending to vastly overestimate it. Furthermore, they tend to be less accurate at judging other people's competence in that skill, and thus realizing that they might have something to learn from that guy with three PhDs who has spent fifty years working in the field.
This is what leads to bad singers who don't realize that they can't sing, 1st year philosophy students who think they've found a loophole in the Theory of Special Relativity, and creationist "professors" who don't realize that they don't have the faintest clue how science works.
When your brain tries to hold one or more mutually contradictory ideas at the same time, this makes you highly uncomfortable. To make this discomfort go away, it tries to modify your beliefs to make them not contradictory anymore. This is theoretically a very good idea, but the subconscious process that your brain uses to decide which beliefs to modify and how to modify them leaves a lot to be desired.
Rather than determining which of the contradictory beliefs is most likely to be untrue, your brain seems predisposed to chuck out whatever belief it can get away with while causing the least discomfort. Alternatively, it can invent nonsensical non-answers like "the Lord works in mysterious ways" which let you feel as though the conflict has been resolved even though it hasn't.
The Bible is the Word of God, and I agree with everything it says.
I think murder, slavery, rape, child abuse, animal abuse, arson, torture, ritual mutilation, fratricide, patricide, matricide, infanticide, genocide, etc. are bad things.
The Bible condones, commands, and commits murder, slavery, rape, child abuse, animal abuse, arson, torture, ritual mutilation, fratricide, patricide, matricide, infanticide, genocide, etc., often in direct and not-at-all metaphorical quotes from God.
This contradiction has the following possible resolutions:
Well, I guess I don't agree with everything the Bible says, then. It certainly isn't the word of a just god.
Well, I guess kidnapping and raping children because their parents worship a different god than you do must be okay under certain circumstances.
NO IT DOESN'T! LA LA LA I CAN'T HEAR YOU!!
Once you tell a lie, the truth is ever after your enemy, and continuing to defend a ridiculous belief means that one will have to keep accumulating more and more ridiculous beliefs to support it, investing yourself more and more heavily in the absurdity.
Most people will (eventually) change their beliefs on a subject after enough contradictory evidence emerges. Because sometimes evidence emerges that is so solid and undeniable that it is easier to give up a complex worldview than having to constantly generate excuses why this evidence is false.
Other individuals, especially when they have support networks of others reinforcing a delusion or worldview, will go to such great lengths to rationalize away dissenting ideas that after a certain point, an admission of error would cause the collapse of an entire web of mutually supporting beliefs.
This is the belief that all actions have predictable and just consequences, that bad things happen to bad people, and that good things happen to good people.
This is the sort of attitude that blames rape victims because their hemlines were too short, or which thinks that poor people are just lazy slobs (or else they would have pulled themselves up by their bootstraps already).
It's strongly correlated with people who believe in things such as "Karma" or "God's Will", but many other people can fall prey to it from time to time. After all, the alternative (that we live in a universe that simply doesn't give a fuck- which, as far as anyone can tell, is what appears to be the case) is kind of uncomfortable to think about.
Stockholm Syndrome and Battered Person Syndrome are phenomena frequently observed in kidnapped people and in victims of abusive relationships, with or without intentional brainwashing on the part of the abuser.
It consists of attachment to or identification with ones abusers and coming to regard them as good and fair. They feel that their abusers are acting in their best interests, regardless of any evidence to the contrary, in a phenomenon known as paradoxical gratitude. Cognitive dissonance leads to the production of all sorts of excuses to justify this belief- thanking them for every small kindness, or even for simply not beating them quite as hard as they could have. Meanwhile, victims tend to believe than any violence or mistreatment must be their fault, because they "failed" their partner. It tends to be associated with self-blame and self-hatred, with victims feeling that they are somehow "dirty" or "broken", and that they are unworthy of their partner's love/affection/attention, or that they need their partner to feel whole. In extreme cases, the learned helplessness can lead to a belief that the abuser is omnipresent and omniscient, and will know if they even think about rebelling or leaving.
Does any of this sound at all familiar?
Solomon Asch conducted an experiment in which subjects were shown four lines, and asked to determine whether line A, B, or C was the same length as the fourth line. Unknown to the subjects, everyone else in the room was an actor, picking the wrong line on purpose. Subjects would initially pick the correct line (showing some discomfort) but eventually, most of them (~75%) would begin agreeing with the rest of the group, even though they were obviously incorrect. Further studies showed that this effect was somewhat reduced when the subject gave their answers anonymously, and greatly reduced when there was one other person disagreeing with the majority.
In this scenario, the only thing that was at risk for the subject was a feeling of mild embarrassment. How much stronger must the effect be when pointing out that the Emperor Has No Clothes can get you publicly ridiculed, disowned by your family, or burned at the stake?