Is the world all there is?

Emma asked:

Hiya, I’m Emma.

Well basically at school, we’re doing about philosophy, and I’ve got to study some people’s views on the world? I was wondering if someone could give me their response in answer to the question, ‘Is this world all there is?’

I just want your opinion, that’s all. If you could help me it would be great.

Thanks, Emma

Answer by Jürgen Lawrenz

Unwittingly, it seems to me, you’ve come up with a question that has exercised thinkers ever since there has been philosophy. But I will answer your question as simply as you wish.

You have to start with a subsidiary question: ‘What is the world?’

When you’ve done this, you can resolve it easily by taking note of some features of the world that can be weighed and measured, like all the objects of science and technology. This would include your shoes, the rain, the trees in the forests, the stars and galaxies, and the atoms and particles of physics. It is the material world.

Many people hold the opinion that this is all there is, and they would describe such other contents of the world as God, angels, saints, spirits, demons, ghosts etc. as figments of the imagination. Of course one could always contradict this opinion by saying: They exist in people’s mind, so they are definitely contents of the universe. Accordingly this is described by many people as the spiritual world.

The people who believe exclusively in one or the other very often do not understand each other. Mainly because the spiritual seems not to actually exist. But this might boil down to the basic problem that ideas cannot be weighed or measured. Yet even those materialists who deny their existence have ideas, so perhaps they are living in self-contradiction?

There are many more things in the universe. Perhaps only on earth? I’m not sure. But where human beings live, there are colors and sensations like pain and pleasure. There are feelings like grief and happiness. The are concepts like beauty and justice. And so on. All these definitely exist. You know it and I know it.

So what you should understand by this is that the most intelligent people who have thought about this problem, have not found an answer. So the answer to your question is: No-one knows; there are only opinions. And none of these opinions can be proved or disproved.

To say the word ‘world’ is to take a guess from what we know, about what we don’t know. In a word, we extrapolate the known on the unknown. But this is not something on which anyone in their right mind could be absolutely certain.


Knowing when an act is done from duty

Ashley asked:

Why is it difficult to show that a person has acted from duty?

Answer by Peter Jones

It would be impossible, not just difficult, to show that a person has acted from any particular motive, or indeed from any motive at all. All we see is what they do. The rest we have to guess, or we might simply believe what they tell us. Either way we cannot show that a person is acting consciously, so other people’s motives must be imputed and never known for certain.

Sometimes when we act it is difficult even for us to tell why we did so. Did we give that Christmas present out of duty, or was it pure generosity?

In short, the reason why it would be impossible to show that a person has acted from any motive is the ‘other minds’ problem. There would be no way to show that they have one.


Answer by Geoffrey Klempner

In the Groundwork for the Metaphysic of Morals Kant argued that the only morally worthy action is one done from duty. But he added the caveat that it can be difficult or impossible to determine with certainty whether a person’s action is genuinely motivated by the thought of duty (the thought of the Categorical Imperative) or some mere ‘inclination’, i.e. non-ethical desire.

If I say to you, ‘I did what I promised because I believe that one ought to keep one’s promises,’ you might still be left wondering whether this really was my motivation, or whether, on the contrary, what motivated me was the thought of the unpleasant consequences that would follow if you, or others, concluded that I am the kind of person who does not keep his promises.

The problem is that there are all sorts of very good prudential reasons for acting ethically, so in a sense an ethical act is often over-determined. It was my duty to do X (e.g. keep my promise) but it was also in my own best interests to do so.

In formulating his theory of the Categorical Imperative, Kant was keenly aware that there are theories according to which the only reason for acting morally is prudential. We do what is right because it is ultimately in our best interests, or the best way to be happy, etc. The problem is, as Kant argued, any such ‘contingent’ motivation cannot be relied on.

The movie The Godfather is a good example: ‘I’ll make him an offer he can’t refuse.’ The fear of death by torture would, for many persons, trump any moral considerations.

Hence, the search for an ‘a priori’ prinicple that doesn’t depend in any way on the beneficial consequences for the agent. The truth of such a principle doesn’t require that we be able to determine whether it is motivationally effective in any given case.

However, if someone does the ethically right thing despite the threat of death by torture, that’s pretty good evidence that what motivated them was the thought of Kantian duty.


Descartes’ method of doubt

Robin asked:

What is the common sense reply to Descartes method of doubt?

Reply by Peter Jones

Descartes’ method of doubt is just that, a method. In order to discover what we know and what we don’t know we identify which of our beliefs we can doubt and which we cannot. As Solipsism is unfalsifiable there is very little that we cannot doubt. If the external world can be doubted, then whatever it is that we cannot doubt can only be a knowledge of ourselves, of our own awareness and identity. In this case any reliable world-theory must be derived from an axiom stating self-knowledge.

This is not an optional method. Nor is It is a new discovery of Descartes’. Aristotle has in mind the possibility of doubt when he writes ‘True knowledge is identical with its object’. If there is no identity, then there is the possibility of doubt. There is therefore no common sense reply to Descartes’ method, we can only choose to use it or not. Common sense would say that we must.

In order to build a systematic theory of the world from the ground up on sound logical principles we must begin with an axiom. This may be an assumption or conjecture, but ideally it would be a certain fact. But what is a certain fact? Cogito was Descartes’ answer, the fact that he was aware he was thinking.

It may be possible to doubt that cogito is a certain fact, since it may be a false reification of a distinct ‘I’ that is thinking, but it is not possible to fault Descartes’ initial approach and method. If we do not take the trouble to establish what can be doubted, then we cannot be sure what we know and what we don’t, and this is obviously not a sound basis for building a world-theory.


Answer by Geoffrey Klempner

Probably the most famous example of the ‘common sense’ reply to Descartes is in the paper, ‘Proof of An External World’ by the British Philosopher G.E. Moore

“I can prove now, for instance, that two human hands exist. How? By holding up my two hands, and saying, as I make a certain gesture with the right hand, ‘Here is one hand’, and adding, as I make a certain gesture with the left, ‘and here is another’. And if, by doing this, I have proved ipse facto the existence of external things, you will all see that I can also do it now in numbers of other ways: there is no need to multiply examples.”

I discuss this ‘proof’ in my YouTube video, ‘Why am I here?’ To me, this looks like a prime example of a philosopher ‘reciting a magic spell’.

There was a time (which is not now) when the idea that you could base philosophy on ‘plain common sense’ seemed to be a viable option. In fact, the idea has appeared more than once in the history of philosophy. The problem is that, although we ultlimately want to defend common sense (there really is a world out there) the way to do it requires more than simply asserting, ‘This is what I believe and I refuse to consider the possibility that I might be wrong’.


Thinking before you speak

Alex asked:

Hi. I’ve been thinking about how we as humans speak and communicate. ‘Always think before you speak.’ a famous quote, but is it really applied to reality.


Do you think while you speak? If so, how?

When speaking, do you think in whole sentences before you speak, meaning you think the whole sentence in your head, and then proceed to utter the thought, OR do you talk and single words/ single thoughts gradually pops into your head Example: You say: ‘There’s a problem’ and you say ‘There’s’ and then ‘a’ pops into your mind, and then you say ‘a’, and then at last you hear ‘problem’ in your mind and say it.

If you’re to present something or to hold a speech to an audience, is it different from what you might do in everyday conversations?

Or maybe your thoughts aren’t said in your mind to a full extent? As for instance when you’re speed-reading. You kind of get glimpse of the word, but still might understand it without verbally saying the whole word inside your head.

Do you even think 3 sentences ahead?


If you’re reading to understand, perhaps a factual book, do you pronounce the words you read verbally in your mind, or do you just look at the words?

Furthermore, do you fixate on one to two words at a time, or do you somehow manage to fixate your eyes and gather 45 words (or even more) per fixation? (peripheral vision).


When listening to other people talk, how does your mind react? Does your mind gradually repeat instantly the words you hear? If you close your eyes when listening, do you still think/hear the words in your mind, as if they were your own? Or do you not repeat the words inside your head, but just listen in another kind of way?

I’ve been looking for answers for years. I’m truly grateful, thank you!

Answer by Geoffrey Klempner

In a way, you have answered your own question. The saying, ‘Think before you speak’ is good advice, but not intended as a philosophical theory about the nature of thought and speech.

If a police officer stops you and asks why you are speeding, it is probably best not to say the first thought that comes into your head, but rather whatever will give you the chance of getting off with a caution. A contrite apology looks like the least worst option.

As a philosophical theory, the notion that we anticipate every statement that we speak out loud with a mental equivalent is a non-starter. And yet, there is a certain way of viewing the mind that makes this theory seem inevitable. This is typical of philosophy, that a simple and accurate account of the facts requires that we resist various philosophical temptations that lead us to veer into nonsense.

For example, on a strict reading of Cartesian dualism, an action of the body (vibrating one’s vocal chords) is preceded by a mental action (thinking the thought). This leads to the idea that, somehow, one does ‘think the thought’ prior to articulating it in speech, but it ‘happens too quickly’ for us to observe it. What a wonder!

This is a good example of the kind of question that Wittgenstein considered in his Philosophical Investigations. We are confused about ‘logic’ or ‘grammar’ of our own language, and led to form all sorts of false or nonsensical theories in order to explain what we do, when we speak, or read, or etc.

So my advice would be: read Wittgenstein!


Gödel’s Incompleteness theorem

Elias asked:

A question similar to this one has already been asked by someone else, however it was in my opinion not answered in the original spirit of the question.

Gödel’s incompleteness theorems as far as I understood them showed that no system of human logic can prove its own consistency.

This is also obvious to common sense because every logic accessible to mankind requires a reason for everything it postulates. Therefore it also needs a reason for its own laws to be true, which cannot be given based on those laws, since those laws have to be established, i.e. reasoned to be true and existing, first.

So it seems to me that when one tries to explain reality by human logic one must conclude that there is at least one ‘Something’ (in the broadest sense of the word) which is illogical in the sense that it is not bound by the laws of human logic and therefore does not require a cause or a reason for it to be. Since this ‘Something’ is illogical and humans have only logic and empirical observation to describe reality (or guess on reality) no description of this ‘Something’ is possible for us (unless we observe it empirically).

This would show that human logic can never explain reality, i.e. answer the question ‘Why is there Something?’ and that either (A)we conclude that there is ‘Something’ transcending logic, which would not be far away from the concept of god or (B) that human logic is initially flawed (since it is not consistent) and we therefore can not know anything. Is this reasoning correct?

Answer by Shaun Williamson

Elias you have the wrong idea about all of this. Logic is not meant to explain explain the world, it simply acts as an explanation of our concept of a logically valid argument.

The theorem you are talking about is called ‘Gödel’s Incompleteness Theorem’, it is not called ‘Gödel’s Inconsistency Theorem’. The Incompleteness Theorem does NOT apply to our system of logic. The Incompleteness theorem applies to our system of mathematics. Our systems of logic can easily be proved to be both consistent and complete.

The problem in mathematics arises because our language allows us to make self referential statements. So for example the sentence ‘This sentence contains five words’ is both a true mathematical statement and a sentence that talks about itself. Gödel was able to use this idea to show that no axiomatic system of mathematics could be proved to be complete and we need an axiomatic system in order to prove the consistency of our system of mathematics. Logic doesn’t suffer from the same problem.

An alternative proof of the incompleteness theorem is contained in Alan Turing’s Theory of Computable Numbers. The American logician Alonzo Church also found an alternative proof of the same thing.

Hope this isn’t too confusing the main points to keep in mind are 1. Logic isn’t meant to explain reality. 2. Our systems of logic are provably consistent and complete 3. We can never prove that our system of mathematics is both consistent and complete unless we restrict it in some way e.g by not allowing self referential statements in mathematics. 4. We can know lots of things given the ordinary meaning of the word ‘know’. However we can also ask questions that we don’t know how to answer and that may not even make sense. It is humans who ask questions and if you ask a question you must be prepared to explain in detail why the question makes sense and what sort of answer you would accept. I am not sure that the question ‘Why is there something?’ makes any sense.


Answer by Peter Jones

I find your reasoning mostly correct. By a similar process of reasoning Kant and Hegel are led to the idea that both the extended universe and human consciousness require an original phenomenon that is not an instance of a category. The categories of thought cannot reach all the way down for the reasons that you give, and so cannot be fundamental. Hegel calls your logically necessary ultimate phenomenon a ‘spiritual unity’. Here the term ‘unity’ would indicate that in no case is it ‘this’ or ‘that’, and it is therefore beyond the reach of logic and the intellect.

However, it would not be ‘illogical’. It would transcend the ordinary world of duality where everything is always ‘this’ or ‘that’, but it would be sound logic that leads us to this conclusion. The importance placed on an understanding of dialectic logic in the Buddhist universities can be explained by the ability of logic not only to refute false views but also to betray its own incompleteness. If we cannot accept your reasoning, and thus the limits of bivalent logic, then we cannot make a systematic theory of the world fundamental. We would always have to leave something out for exactly the reasons you give. This is Russell’s paradox, the reason why he could not axiomatise set-theory. The attempt to make any bivalent logic fundamental leads to intractable problems of self-reference.

The question of whether we can acquire certain knowledge by the use of logic is easy. Logic produces only relative truths and falsities. This need not be a pessimistic view of knowledge, however, for it is possible to know things without any dependence on logic. You might know you are in pain, for instance. For the third time today I’ll quote Aristotle’s crucial observation that ‘true knowledge is identical with its object.’ No mention of logic.

As you say, this analysis of the limits of logic leads us to the idea of something that seems rather like God. But it can be seen that where philosophers undertake this analysis they usually call this phenomenon by a different name such as Tao, Nirvana, Ultimate Reality, Unity, Godhead, Bliss, the Authentic, the Undifferentiated, the First or Original. Plotinus uses the term ‘Simplex’, which indicates its lack of conceptual complexity, the idea that it lies beyond the categories of thought, or, in the words of one Christian mystic, ‘beyond the coincidence of contradictories’.

But this would not mean we cannot know it. We can know it intimately if we are it, and we must be if, as logic suggests, Reality is unified at an ultimate level. For this view we need not abandon logic, but we would need a logic of contradictory complementarity. Hegel’s idea of ‘sublation’ is important here. If you are mathematically-minded then for an example of how such a logic would work you might like to read George Spencer Brown, who solved Russell’s Paradox in his book ‘Laws of Form’.

Your final question asks whether human logic is flawed because it is not consistent. I would say not. It can be consistent just as long as we do not imagine it is complete. It is only when we imagine (in either ontology or epistemology) that the duality required by the functioning of our intellect reaches all the way down that our logic becomes inconsistent and flawed. This was Russell’s problem. He did not know (or want to know) religion well, so did not have the principle of ‘nonduality’ at his disposal and could not transcend dualism for his philosophy or mathematics. If, however, we accept that the universe is not the set of all sets, which would be a paradoxical idea, but something Kantian that is entirely beyond sets, then our system of logic can be consistent from the ground up, as is demonstrated by Brown with his ‘calculus of indications’.

If you wish to pursue these issues then a directly relevant experimental essay is ‘Exploring Connections: Music, Cosmology and Mathematics’ at


Denying the consequent

Meg asked:

If you pass the test, then you’ll get an A for the course.
You didn’t get an A for this course.
Therefore you didn’t pass the test.

In this argument, we are ______ the consequent.

Answer by Craig Skinner

We are DENYING the consequent.

We are dealing here with a Conditional (If X then Y: expressed in symbolic logic as X–>Y).


Conditionals yield 4 arguments in classical logic, two valid and 2 invalid (fallacies):

X is the case
Hence Y is the case

Y is the case
Hence X is the case
Invalid (Fallacy of Affirming the Consequent)

X is not the case
Hence Y is not the case
Invalid (Fallacy of Denying the Antecedent)

Y is not the case
Hence X is not the case

Running through each using your example.

1. You pass the test, so, as the conditional says, you’ll get an A.

2. You get an A, but this could be due to other good results even though you failed the test, so it doesn’t follow you passed the test. There are other ways of getting an A, passing the test is just one of them.

3. Same as 2. You fail the test. Fine, there are other ways to get an A.

4. Same as 1. If you pass the test you get an A. But you haven’t got an A. So you can’t have passed the test.

The Principle that Denying the Consequent entails Denying the Antecedent (your example, and 4. above) has the Latin name ‘Modus Tollens’ meaning ‘Way that Denies’.

The Principle that Affirming the Antecedent entails Affirming the Consequent (1. above) has the Latin name ‘Modus Ponens’ meaning ‘Way that Affirms’.

These Principles were, I think, first explicitly stated by the Stoics.