Atheism: Definitions and Arguments
What is atheism?
Atheism is, as the name suggests, the denial or rejection of theism. For present purposes I will take theism to be the belief that the God of sophisticated monotheistic religions exists. The God of monotheism is an entity that plays a role in explaining certain features of the observable world e.g., the existence of the physical universe, why the universe is ordered rather than chaotic, why humans exist.
The standard formulation of atheism comes in two varieties depending on whether it stresses the affirmation of the non-existence of God or the denial or rejection of the existence of God.
The entry on atheism in the Rutledge Encyclopedia of Philosophy begins with the stress on the affirmation of the non-existence of God.
Atheism is the position that affirms the nonexistence of God. It proposes positive belief rather than mere suspension of disbelief.
However, sometimes atheism is characterized in terms of the proposition that is rejected. For instance, the American Rutledge Encyclopedia entry on atheism defines atheism in terms of the rejection of belief in God, or someone who thinks that the proposition “God exists” expresses a false state of affairs.
Someone may reject the claim that God exists on grounds that it is incoherent, and contains logical contradictions, e.g., they may reject the claim that God is three persons in one, because it is part of our concept of a person that no person can be identical with any other person, and so it is incoherent to claim that God is identical to three person (or person like entities). Similarly they may reject the claim that God is perfect when coupled with the claim that God needs to be worshipped since a need suggests a lack of something whilst perfection suggests that the entity is lacking in nothing. Hence someone may reject the claim that God exists when talking about the typical characterization of the God of monotheism. In rejecting this claim they are claiming that the proposition expressed by “God exists” is false or cannot be true.
Atheists may also reject the claim that God exists indirectly, by embracing the attitude of naturalism that is reflected in the current scientific world view - the view that events in the natural world have natural explanations, and that supernatural explanations have no room to play in explaining the physical universe. Science has not always adopted the attitude of naturalism. In the past supernatural causes were accepted as playing a role in the observable world e.g. the motion of the planets and there is no essential feature of science that makes it adopt the attitude of naturalism. It has adopted this attitude because of the past success of natural causes and the failure of supernatural causes in explaining features of the observable world.
Since the God of monotheism is an entity that plays a role in explaining certain features of the observable world e.g., the existence of the physical universe, why the universe is ordered rather than chaotic, why humans exist, (as well as the more outrageous claims such as atheists are responsible for global warming) then someone who adopted the attitude that such events were explained by natural rather than supernatural causes would be indirectly rejecting the existence of the God of monotheism. However even though someone who adopted the attitude of naturalism would believe that all natural events have a natural explanation they may not draw the conclusion that God does not exist if they do not see the connections between such beliefs.
The person who believes that the events in the observable world will have a natural explanation rather than a supernatural explanation but fails to draw the conclusion that the God of monotheistic religions does not exist is like someone who believes that all men are animals, and all animals are mortal, but does not draw the conclusion that all men are mortal.
With the above qualifications in mind, we get something very close to the starting definition:
Atheism is the position that affirms the nonexistence of God, or any view which entails the non-existence of God or gods. It proposes positive belief, rather than mere suspension of disbelief.
Agnosticism – Lack of knowledge.
Atheism is distinct from agnosticism although the two overlap. Agnosticism is the view that denotes lack of knowledge on the existence of God (or more widely on any topic), in contrast with Gnosticism, which denotes knowledge of God. It is often coupled with the distinct view that, since God’s existence cannot be proved or disproved, the rational position to take on this topic is simply non-belief, or the suspension of judgment. Agnosticism has traditionally been used to mark a midway point between atheism and theism, which gives the following table.
1 Gnostic Theist: Believes that God exists and claims to know that God exists.
2 Agnostic Theism: Believes that God exists but does not know that God exists.
3 Agnostic Simpliciter: Neither believes nor disbelieves. Does not know God exists or does not.
4 Agnostic Atheist: Believes that God does not exist but does not know God does not exist.
5 Gnostic Atheist: Believes that God does not exist and claims to know that God does not exist.
Atheism as Non-Belief.
However, there is a widespread popular use of 'atheism' that exists amongst many (if not most) atheists that defines atheism as simply the lack of belief in God. This view is so widespread that it may now be the dominant view in popular culture. As a contributor for The Guardian, Peter Thompson writes that atheism,
…as atheists are keen to point out, says nothing about the atheist's beliefs. It is simply the absence of a belief in something and does not constitute a belief in its own right.
This view has its own intellectual history going back to the 1800’s. It is shared by some philosophers who have written on atheism, such as Michael Martin. On this view, the difference between atheism and agnosticism is not in terms of lack of belief, since both views share that characteristic. Instead it has been proposed by J.C.C.Smart that if someone estimates the various probabilities of theism being true, on the evidence available to him, then one can rank theism and atheism depending on how likely they think it is that God exists or does not exist.
On this view, we have the following categories, where more than lack of belief is required in order to be an atheist, the person must also think that, on the balance of probabilities, it is unlikely that God exists.
1 Gnostic Theist: Believes that God exists, is certain that God exists (probability of 1).
2 Agnostic Theism: Believes that God exists, thinks it highly likely, but is not certain.
3 Agnostic Simpliciter: Neither believes nor disbelieves, and takes it as equally likely that God exists or does not.
4 Agnostic Atheist: Is skeptical that God exists, thinks it highly unlikely that God exists, but is not certain.
5 Gnostic Atheist Is skeptical that God exists, is certain that God does not exist – probability of 0.
Notably in the above definitions of atheism the requirement of believing that God does not exist is absent. From the above we can see that atheism includes both definitions.
1: The belief that God doe not exist (or what entails this).
2: The lack of belief in God.
The first claim has been called “positive atheism” or “strong atheism”, and the second has been called “negative atheism” or “weak atheism”. The first of the above claims is the stronger of the two, since it entails the latter. That is to say, if you believe that there are no gods, you should also lack a belief in any god; otherwise you will have contradictory beliefs. The second does not entail having any belief about the non-existence of gods.
This second view is probably best not construed as a claim that cats, dogs, and infants are atheists, or that those completely ignorant of religion are atheists even though these creatures lack the belief in God. This is because such creatures are not making any judgment about the probability of whether God exists or not and this latter feature is required for distinguishing atheism from agnosticism simpliciter (the view that God’s existence and non-existence is equally likely).
What the two views have in common and what marks them out as distinct from agnosticism simpliciter is that both share the view that the God of monotheism is perceived as being an improbable thing to exist. The core dispute between the two views is over whether the perceived improbability of such a God existing entails that the person should believe that such an entity does not exist or whether the perceived improbability of such a God existing entails that one should simply doubt that such a God existed and suspend belief on the matter.
Given that the central dispute between atheists over the definition of atheism involves whether a person should believe God does not exist or suspend belief on the matter it will be worth sketching out an outline of what beliefs are. In so doing we may belay some confusion.
What are Beliefs?
Since the definitions of atheism involve the term ‘belief’, it will be useful to clarify some central notions that surround the concept of belief. The term "belief" is used in philosophy to refer to the attitude we have whenever we take something to be the case. In this sense, the term is used very widely and covers what we may call ‘G. E. Moore beliefs’. These are the things that we take for granted and feel pretty certain about during our everyday interaction with the world, such as “I have hands”, “this is a table,” and so forth. The term is also used to cover the more speculative aspects, such as “God exists”, “Intelligent life on other planets exists”, and so forth.
Attitude and Content
It is important to distinguish the psychological attitude of belief from the content of what is believed. The psychological attitude of belief is an autobiographical statement; it tells you about some particular person’s psychological state. It is typically reported by someone saying “I believe that God exists”. In contrast, the content of belief is what the person takes to be true; it is about an actual or possible state of affairs in the world, e.g., “God exists”. To illustrate this distinction, consider a world in which no God exists, and a person who asserts the following:
I believe that God exists.
If we are focusing on the content of what the person believes, then we would be focusing on the proposition that God exists. Since, for the sake argument, we are in a world without God, the claim is false. If this were a world in which God existed, the proposition would be true. However, if we are considering the statement as an autobiographical remark about what the person believes then, so long as the person is speaking clearly, the claim is true, since that statement reflects what they believe. Confusion can arise when people use the above form of expression as ellipsis for the proposition “God exists”, only expressed with some degree of doubt, rather than as an autobiographical remark.
It is important to get clear on the distinction between belief as attitude and belief as content, because some atheists can mistakenly think that, if they reject the claim (belief as content) that God exists, they have said nothing about whether they believe that God does not exist. They have, since to reject the claim God exists is to represent the world as if God did not exist. Consider someone who rejects the claim that his son is alive. Someone who rejects this claim is representing his son as being dead, since there is no intermittent state of being between being alive and dead. This is why the phrase,
I don’t believe that God exists
Is not a good indicator of whether the person rejects the claims of the theist or not. Strictly speaking, this tells us nothing about whether the person rejects what the person, who asserts that God exists, claims to be true. The one lacks a belief that the other one has. The problem is further confounded by such phrases as “I don’t believe” being elliptical for “I think that is false”.
Consider the scenario whereby someone believes that Elvis is not dead and they ask you whether you believe that Elvis is still alive. You may reply that
I don’t believe Elvis is still alive
If we take this literally it indicates that you lack the belief that Elvis is still alive but does not indicate that you think Elvis is dead or that the person who thinks Elvis is still alive has a false belief. However, I think that many people treat the above expression as an ellipsis for the thought that Elvis is dead in the same way that many people ay treat the expression “I don’t believe that God exists” as ellipsis for “I believe that God does not exist.”
It is important to note that if you construe the claim “I believe that God exists” as an autobiographical remark, then it is impossible to reject this claim (think that it is false), without thinking that the person is mistaken about what they believe. You cannot reject someone else’s autobiographical remark by citing an autobiographical remark of your own, just as you cannot reject my claim that I ate marmalade on toast this morning by citing your skipping breakfast. Similarly to reject the claim that God exists is not to lack a belief on the matter (which tells us nothing about whether you believe God exists or not) but to think that God does not exist.
However, there is another sense of reject, which is to reject an invitation to share the belief that someone else has, without making any kind of judgment about whether the belief is true or false. Consider being asked whether a defendant in court is guilty of a certain crime. We may be invited to consider that the defendent is guilty by the prosecution but reject this invitation. We may also reject the invitation to view the defendent as not guilty. In this sense of reject, we simply reject what we are being invited to believe. However, in such cases we naturally refuse to believe the defendent is guilty or not guilty when there is insufficient evidence either way so the defendent has an equal chance of being either. This is not the case with atheism - the atheist does not think that God is as equally likely to exist as not exist even on the atheism as a lack of belief model.
The use of "I don't believe that" is often unclear.
The use of "I don't believe that" is often unclear.
These two senses of reject are often confused.
The Arguments for Atheism
As mentioned, agnostics have tended to distance themselves from atheists on the grounds that agnostics treat religious claims as being plausible claims that could equally be true or false, like betting on a coin that could land heads or tails, whereas many atheists tend to denigrate agnostics and, in so doing, reveal their belief that the existence of God is highly unlikely rather then equiprobable. There clearly is a difference between someone who regards the existence of God as plausible but is undecided on the matter (and who does not see themselves as being an atheist), and someone who regards the existence of God as utterly implausible and thinks that people should not believe this.
The Tea Pot Analogy
If atheists focus only on perceptible evidence as reasons for belief or disbelief, then they may be led into an uncomfortable position whereby there are no reasons to believe God exists, or to believe that God does not exist. If there is no reason to believe or disbelieve then atheism will look indistinguishable from agnosticism. On the other hand if atheism is to be distinct from agnosticism some reason is required for claiming that the existence of God is improbable (more likely to not exist than exist).
An oft used analogy to reject such impartiality, with regards to belief in God, is the tea pot analogy - the idea that belief in God is analogous to the hypothesis that there is a tea pot that is in orbit between Earth and Mars. If the hypothesis is careful to state that tea pot is so small as to avoid detection by even our most powerful telescopes then the hypothesis would not be able to be falsified. However even though the assertion could not be disproved this should not lead us to suspend judgment on the matter. Instead we should doubt whether there is such a tea pot in orbit.
That is to say, given two hypothesis:
A: There is a tea pot in orbit around the Sun.
B: There is no tea pot in orbit around the Sun.
The latter (B) is vastly more probable than the former and, as such, we should doubt whether A is true. However in doubting whether A is true we need not affirm that B is true. We may doubt both but not to the same degree which is just to say that we think one hypothesis is more likely than the other.
Further, since there is no more evidence for there being a tea pot in orbit around the Sun, than there is for there being a God, we should similarly doubt the hypothesis that God exists. We may also go on and accept the hypothesis that there is no such God if we are strong atheists.
There are important disanalogies between the tea pot and God – namely that the tea pot is open to potential verification and does not play a role in explaining anything of significance in the universe. The God of theism, by contrast, is posited as an explanation of the physical universe and why it has the form it has, including containing humans. Since the God of theism is posited as an explanation for certain features of the natural world these features are said to constitute evidence for the existence of the God of theism. In contrast there is no evidence for the existence of the tea pot since the tea pot does not explain any features of the natural world.
However, despite these differences the basic principle remains the same: given two hypothesis, we should reject the most implausible and accept the most plausible one. That is to say between the competing hypothesis:
A: The features of the natural world x,y,z are best explained by a supernatural God.
B: The features of the natural world x,y,z are best explained by natural properties.
We should doubt A far more than we should doubt B because B is far more probable than A. That is to say we should all be atheists in the weak sense of the term. Of course if we go on to think that B is true then we will be entitled to think that A is false with the same degree of certainty (unless we are in some degree of doubt about the entailment relation) that we think B is true since the truth of B entails the falsity of A. That is to say we will be strong atheists.
From the above we can see that the strength of atheism increases as does the extent of scientific explanations of the universe.
How Not to Argue for atheism as Non-Belief
Many atheists claim to simply lack a belief in God rather than actively disbelieve in the existence of God. This is a legitimate position to take when considering a hypothesis that we regard as possible to be true but unlikely to be true. However those most vocal in arguing that atheism is a position of non-belief also simultaneously claim that the existence of God is an outlandish thing to believe in, as outlandish as belief in fairies or other mythical creatures.
Here is the write Paula Kirby describing such a view:
Atheism is not in itself a belief. Few atheists would be so bold as to declare the existence of any god at all utterly impossible. Atheism is, quite simply, the position that it is absurd to believe in, much less worship, a deity for which no valid evidence has been presented.
Paula Kirby defends the ‘atheism is not a belief argument’ on the grounds that:
A: If she cannot be certain that there are no gods, then she should not deny, disbelieve, that any such gods exist.
Whilst elsewhere, like many atheists, she thinks that:
B: It is as absurd to believe that any gods exist as it is to believe in unicorns.
1: These two claim, the suspension of belief, and the belief that something is outlandish or ridiculous to believe in do not sit comfortably together. As Julian Baggini observes, if we take some claim to be outlandish and incredible, we naturally disbelieve such a thing (think that such a claim is false), rather than suspend belief:
Who seriously claims we should say 'I neither believe nor disbelieve that the Pope is a robot', or 'As to whether or not eating this piece of chocolate will turn me into an elephant I am completely agnostic'. In the absence of any good reasons to believe these outlandish claims, we rightly disbelieve them, we don't just suspend judgement. (Baggini very short introduction to atheism p.35)
There are good reasons for thinking that the suspension of belief is not something that can be brought under the will or conscious control, but instead belief formation is largely an automatic process, i.e., try believing that there is an elephant in the room, or that other people do not exist, or that there are invisible people living in your coat pocket. We may entertain these ideas, but we do not affirm them as true, and such ideas do not guide our lives. If so then belief formation is not something we choose; it is a largely automatic process that depends on what we take to be the case. If something is highly likely, we believe it to be true and, if it is extremely unlikely, as in the example of the Pope being a robot, we believe it to be false.
There is no reason to think that the author, Paula Kirby, or anyone else is capable of suspending judgment on things that they are not absolutely certain of, e.g., that people read The Hibernia Times or Washington Post then we have reason to believe that people can be mistaken about the principles that guide how they acquire their beliefs. This means that they have the belief that their beliefs are guided by a principle (described in A) when their beliefs are not in fact guided by any such principle.
2: Many atheists represent religious belief as analogous to belief in fictional entities, for which there is no evidence of their existence. However, the attitude that most people have towards fictional entities is, as the name suggests, one of disbelief or belief in their non-existence. There is evidence to suggest that the attitudes we have to things is influenced by association such that, if we associate religion with fictional entities, we will think that religion consists of fictional entities, i.e., entities that do not exist. So, far from suspending belief on the matter, such atheists are likely to believe such entities do not exist.
This raises the question:
How can atheists, or anyone else for that matter, be deceived or mistaken, so that they deny having the (negative) beliefs that they actually have?
When we search for information about the world or ourselves, our preferences for what we want the world or ourselves to be like influence where our attention is focused. People tend to be more critical about what they do not want to believe, and more accepting of information that fits what they want to believe. Given that there are a host of advantages to portraying oneself as lacking in belief, it is not surprising that many atheists like to represent themselves as holding this position, even when there is good evidence available that this position does not capture what they believe.
1: Avoidance of common characteristics
Atheism has grown in popularity in recent years and, as it has done so, it has taken on something of a group identity that sets itself as opposed to theism. Whilst it is true to say that atheism is opposed to theism in the strict logical sense – theism is the belief that God exists, whereas atheism denies this or asserts its opposite - modern atheism seems to have opposed itself to a host of traits that are associated with religious belief, but which do not form any essential part of an atheistic world view.
Theists typically believe in an objective morality that isbound up with God, believe in souls, and that revelation is a way of knowing about the world. Such a view is common to the Abrahamic religions. In contrast, atheists are often accused of lacking a belief in objective morality, only believing in physical things, and that science is the only way to know about the world. These things do not logically follow from atheism, and there seems little reason why atheists should have these other beliefs, although it appears that, among the folk, many do endorse the opposite set of traits from theists. It may be that, in wanting to distance themselves from theists, atheists are more likely to endorse the opposite set of traits that theists endorse.
Two attributes that are commonly associated with religion are "belief" and "faith". If atheists want to distance themselves from theists, they may be motivated to avoid admitting that their position is associated with belief, or any element of faith. One way of maintaining a distinct identity from theists is to deny that they have any of the same characteristics, including denying that they have a belief on the question of God’s existence.
2 Avoidance of the burden of proof
There are conversational norms whereby a person who asserts some claim, whether it be that God exists, or whether it is the opposite claim that God does not exist, has accepted the burden of proof to explain and justify their position. If atheists can pretend that they lack a belief or lack a position on the topic, then they can avoid the burden of proof. Since atheism is a popular movement, many atheists are likely to be unfamiliar and unskilled in justifying their position. Hence, once would expect them to be motivated to avoid adopting the burden of proof. The problem with pretending to have no position on this topic is that our behavior often reveals what we really think, more than our explicit denial of having any beliefs on the topic.
3: Fear of being seen as dogmatic.
Atheists may not want to assert that God or gods do not exist, or report to others their belief that there are no gods, because they fear that they will be seen as dogmatic or mistaken. After all, if you assert that there is no monster under the bed and there turns out to be one after all, you will have been mistaken. However, there is no reason why someone who believes that monsters do not exist, given the lack of evidence to date, should be seen as dogmatic if they are willing to change their mind at a later date, when the evidence changes. Not wanting to assert that you believe there are no gods is compatible with believing that there are no gods.
There is a legitimate distinction between atheism as the belief that God does not exist and the lack of belief in God.
In order for this distinction to capture what atheists actually believe underpins their lack of belief in God it needs to make it clear that atheism is accompanied by the belief that the existence of God less likely than its existence rather than equiprobable in order to distinguish this from the more neutral agnostic (or agnostic simpliciter) position.
Some atheists who perhaps ironically most vigorously defend the atheism as non-belief position may see theism as being so implausible that they actively disbelief rather than suspend judgment. That is to say they have the beliefs that they deny having. Further they may also have mistaken beliefs about the way that they acquire and reject beliefs.
There seems little reason for atheists to suspend belief on matters they see as vastly implausible, as contrasted with rejecting such claims as false or mistaken. However, one can reject such claims in a non-dogmatic way. To adopt a non-dogmatic position, all one needs to do is believe that God does not exist, coupled with the willingness to change your mind should the evidence change, or with the acceptance that your belief could be mistaken.
 What is Theism?
Since atheists reject or suspend judgment on the claims of theists, it will be useful to quickly outline theistic positions with regards to God. Theism is the view that a personal God that transcends the natural world exists, or exists apart from the natural world. God of the monotheistic religions is commonly characterized as a type of immaterial being, who is the creator of the physical universe and everything in it, along with a host of other attributes: powerful, good, loving, just etc. This is distinct from pantheism, which is sometimes taken as an attitude of awe or reverence for nature (and so indistinguishable from) atheism and, at other times, taken to be the attributing of mind-like properties to nature as a whole, e.g., a consciousness of the biosphere which is a view that I shall not discuss here.
Philosophers who defend theism often claim that the attributes of God are used in a metaphorical, analogical, symbolic or non-literal sense. In contrast, non-philosophers tend to view these attributes of God in literal terms, often being described as believing in an anthropomorphic God. There are also differences in terms of how creation is understood, for instance, creation can be understood in a temporal sense in which God is supposed to have made the universe, before which it did not exist, and a non-temporal sense in which the universe is supposedly dependent on God sustaining it, and molding its form, so that it is suitable for intelligent life. These two views are often combined, but the latter view is sufficient to avoid the claim that theism is false if matter existed for eternity. However, central to the God of monotheism is the belief that a supernatural deity exists and explains (in the sense of is causally responsible for) some features of the world, e.g., the existence (or continued existence) of the physical universe, the fine tuning of the cosmological constants, and human existence.
 The proposition “God exists is false” has the same truth conditions as the proposition “God does not exist”. Whether these two propositions express the same thought depends on how thoughts are to be carved up i.e., whether they are carved up objectively in terms of the state of affairs they denote or whether they are carved up subjectively in terms of the attitude that the speaker has towards them. Depending on which view one takes, one will say that these express the same thought in different ways, or that these express different thoughts about the same state of affairs.
 What is natural is defined in terms of whatever properties pull their weight in the empirical (natural) sciences. They are the properties that belong to the natural sciences and belong there because of their role in explaining features of the observable universe but they need not themselves be observable.
Atheism and Etymology
It is sometimes argued by atheists that the etymology of atheism is from the Greek meaning “without God”. Since the theist believes that God exists, the atheist is someone who is without the belief that God exists. This argument has two problems.
The first is that it commits the fallacy of etymology, which is a genetic fallacy that describes someone who claims, erroneously, that the historical meaning of a word or phrase tells us what its actual present-day meaning is or ought to be. This is a linguistic misconception that confuses the origins of the term’s meaning with its current meaning. For instance, if all we knew about the term was its etymology, we would be very confused as to what someone who ordered Tagliatelle was ordering (little cut ones).
The second is that, we are meant to take the origin of a term as a guide to its current meaning, and so conclude that atheism means the lack of belief. However we cannot take the term as a guide to its current meaning without knowing how the current term is used and whether such usage is accurate. As I have argued above, those most vocal in arguing that atheism is non-belief actually have the beliefs they deny having so this actually undermines the argument that atheism is the position of non-belief. Nevertheless a case can be made for atheism as the position of non-belief so long as it is coupled by the claim that the existence of God is less likely than Gods existence and does not stray over into making the existence of God into something manifestly implausible.
The You Cannot prove a Negative Argument
There is a popular view that a person cannot prove a negative, by which is meant that you cannot prove that something does not exist. You can only prove what exists. This claim does not stand up to a moment’s scrutiny. For instance, consider someone telling you that you cannot prove that an elephant is not on your head. Clearly they have lost their marbles. The reason you can prove a negative, i.e., prove something does not exist, is because the existence of things leaves a trace in the world, e.g., the reason that an elephant has not stepped in my butter is because the butter is still intact. If an elephant had stepped in my butter, or snuck into my living room, the world would be altered in a certain way.
However, the non-existence of God may be thought of as more difficult to prove and it is, for here there is plenty of evidence of non-existence, but not the same kind of certainty regarding elephants walking in your butter. The claims are analogous only in that the existence of elephants, like the existence of God, is expected to leave certain imprints on the world. If God created the world so that humans could come into existence, then we would expect that we would be here pretty much straightaway (after all, an omnipotent being cannot fail to bring about what it intends). However, unbeknown to people who were wondering what the origins of the universe and humans were two thousand years ago, the universe is actually very old, and human life is comparatively recent. So the evidence suggests that the universe was not made by an omnipotent being who intended us to come about. And it gets worse; we now know that the sun's energy is expanding, so that life on earth will eventually be destroyed and this looks like a natural process that all inhabitable planets go through. So, far from the universe appearing made fit for intelligent life, it looks incredibly hostile to any prolonged existence. This is the footprint in the butter that gives us reason to say that the universe was not designed by any omnipotent God for the purpose of intelligent life. It is not a proof but it is a good reason for rejecting belief in God.
Assumptions and Beliefs