'Does reality really exist?'

“Let's take my apple example. I can see it, feel it, taste it and smell it. But if I'm dreaming or under hypnosis or drug induced, the apple then isn't real. And being awake may not matter if the apple is an illusion or if my senses are altered to create that apple.

“So does reality really exist? When can we trust our senses with 100% reassurance?” - Philosophy Explorer

You can say that instead of the question 

"Does reality really exist?"

the question should be: 

How do I know that I'm not dreaming, etc.? 

After all, such scenarios (as is often the case) seem to be written into questions such as "Does reality really exist?" In other words, the sceptic is, in a way, begging the question or at least assuming some preliminary questions and answers.

The question is, then, about knowledge: 

How do I know that reality exists? 
How do I know I'm not dreaming? 
How do I know that this apple isn't a Ford Escort?

If you miss out the word "know" from the question, then you're certainly feeling, tasting and smelling something that you think is an apple. Those experiences are real even if dreamed. Those experiences are real even if simulations of the real thing.

I personally wouldn't ask a question like "Does reality exist?". I'd stick to something traditional like: 

"How do you know your hand in front of you exists?"

Science’s Communal Spirit & Philosophy

An essential part of science is what various commentators have called its “community spirit”. That is, scientific truths aren’t confirmed, justified or accepted (rather than simply “discovered”) intuitively, in isolation or through meditation. (This isn’t to discount independent scientific theories, original speculations and the reality of scientific genius.) Scientists don’t pluck out truths from the air above their heads. (One can philosophically dispute the use of the word “truth” in science; though this isn’t the place to do so.) As Bertrand Russell once put it:

“A body of individually probable opinions, if they are mutually coherent, become more probable than any one of them would be individually. It is in this way that many scientific hypotheses acquire their probability. They first fit into a coherent system of probable opinions, and thus become more probable than they would be in isolation.” 

Perhaps the prime distinction (at least traditionally)between science and both philosophy and religion is that scientists deal with what’s called “probable opinions”; whereas philosophers and religious thinkers/leaders deal with truths. In that sense, an individual scientist wouldn’t think that he has found a/the truth in a situation of “splendid isolation”. However, if there were a general consensus within the/a scientific community on his probable opinion, then perhaps the honorific “truth” could then be applied to his opinion.

And just as a philosophical coherentist compares an individual belief with all the other beliefs within the given system it is part of, so a scientist needs to place his probable opinion within his own scientific community. In addition, just as the individual scientist relies on his own scientific community, so too does a particular scientific community rely on other scientific communities (i.e., those which may be focussing on different areas of research or investigation).

And what Ludwig Wittgenstein argued about “private knowledge” can now be applied to the situation of the lone scientist. Indeed the term “lone scientist” is almost a misnomer when taking into account the history of science and how science is actually practiced. That is, there can’t really be genuinely lone scientists; just as Wittgenstein argued that there couldn’t really be lone epistemologists or people with private truths of private knowledge. Sure, there have been many highly original and sometimes unacknowledged scientists. However, their work only became acceptable science when legitimated by the scientific community (or communities in the plural) as a whole. (A good contemporary example of this is the physicist Julian Barbour who works outside the academic system of physics and who yet still influences that system.)

The scientific approach is antithetical to the philosophical or religious/spiritual approach. In many instances philosophers and religious thinkers/leaders worked in complete isolation. Indeed there’s a sense that because of the nature of philosophy (loosely, its — as it were — a priori method), then clearly philosophers don’t need to cooperate in the way that scientists cooperate. Indeed that almost solipsistic attitude was challenged — by a philosopher — in the 19th century. 

Take the 19th century American philosopher C.S. Peirce. He believed that philosophers should learn as much as they can from science and scientists. (This was primarily because of Peirce’s penchant for science and his many years in the laboratory.) He even thought that philosophers should actually use scientific methods. (Peirce also believed that philosophers and even logicians should study the way scientists reason.) According to Peirce, the idea that a single individual could arrive at the truth entirely on his own is a complete mistake. Yet although philosophers obviously read and analyse the works of other philosophers, they’re still doing so (arguably) within the context of their own intellectual autonomy.

Having said all that, it’s nonetheless argued that the “analytic tradition” of philosophy has (to some extent at least) been a cooperative endeavour in which philosophers not only learn from each other; but, in many instances, they actually work with each other too. (Think here of the Vienna Circle or W.V.O. Quine writing a paper alongside Nelson Goodman — see here.) Of course what really makes analytic philosophy a cooperative effort is the shared vocabulary and set of technical tools/terms — i.e., the shared philosophical and logical toolsterms that are utilised in all areas of analytic philosophy and research. And because of that, both analytic realists and analytic anti-realists, analytic dualists and analytic anti-dualists, for example, use the same tools and belong to the same philosophical tradition. Of course there will be peripheral disputes on terms and definitions (as well as on the reality of that tradition); though such disputes usually still occur within the context of a generally cooperative environment.

Perhaps we could say here that if philosophers don’t even share a vocabulary, then the conversation couldn’t even get started. Philosophers would be debating at cross-purposes. Indeed isn’t that what actually happens when, say, a analytical logical empiricist debates with a Parisian deconstructor? And that is a lesson that philosophers should (or must) learn from science.

Against the Science of Mind

"The reality of the external world to which science points has no psychic depth, no depth of being. It is a plastic mass of events. When scientists study Man, they want to prove that the mind, the psyche, the being of Man, is the effect of bodily existence and thus an effect of matter. They conclude that if the mind is caused by matter, then it is basically unreal, secondary, not a primary reality." - Granth

I'm not sure if there is such a consensus in science on the mind. Even in the limited domain of 'materialist' philosophy of mind I don't think that there is such a consensus.

Granth refers to "no psychic depth, no depth of being" of science. These technical terms seem to be taken from a specific philosophical tradition so it will be hard for people unfamiliar with that tradition to know what such locutions mean.

Granth also says that scientists (all of them?)

 

"want to prove that the mind, the psyche, the being of Man, is the effect of bodily existence and thus an effect of matter. They conclude that if the mind is caused by matter, then it is basically unreal, secondary, not a primary reality".

 

It doesn't follow that if a scientists argues (or shows) that "the mind is caused by matter" that he also believes that it's "unreal, secondary". A forest fire can be caused by a discarded cigarette; though the fire is still real even if it has causes. The mind and brain can even be acceptably different domains, according to scientists, and it still be the case that the brain (or something larger) is the "cause" of the mind. Scientists, on the whole, are no longer interested in erasing mind or consciousness from the equation. In fact only a few scientists ever were completely that way inclined.

As for "the Being of man" - that seems to be the technical language of a specific philosophical tradition which, presumably, not all people will be aware of even if they know much philosophy. What is "the Being of man"?

Karl Popper on the Infinite Variety of Facts

It is because there is an ‘infinite variety of facts’, and each one of this infinite variety has itself an ‘infinite variety of aspects’, which we have to approach the world of facts with presuppositions. It may be an ideology, a ‘scientific theory’, a prejudice, or whatever.


The ‘theory’ itself makes the choices in science. The ideology makes the choices in historical research and political knowledge.

So these theories, or even prejudices, act in a similar manner to the un-argued premises or axioms in arguments or logical/mathematical systems. That is, because of the infinite amount of facts that are possible candidates for comment and research, something prior is required to get the ball rolling; just as the sceptical doubt in the very act of doubting must presuppose certain things that are beyond doubt (at least within specific contexts). The theory, or prejudice, then, allows the theorist to do some ‘proper ignoring’ of certain facts or possible facts, as David Lewis put it (“within the context” of epistemology). The theory, in a certain sense, selects what facts should be concentrated upon and which should be ignored. It therefore determines the scope of the investigation and research. Without an a prior theory or prejudice, as it were, the theorist would be faced with a manifold of possible facts. Such a bombardment would serve no purpose in either science or philosophy.  As Popper puts it:

“… a science is not merely a ‘body of facts’. It is, at the very least, a collection, and as such it is dependent upon the collector’s interests, upon a point of view. In science, this point of view is usually determined by a scientific theory; that is to say, we select from the infinite variety of facts, and from the infinite variety of aspects of facts, those facts and those aspects which are interesting because they are connected with some more or less preconceived scientific theory.” (259)

The scientist must have ‘interests’ and ‘points of view’. More than that: his interests and points of view help determine the direction in which his investigations go. Indeed without such interests and perspectives, the scientist would not in effect go in any direction in his investigations. He would be in a continual state of cognising more and more facts, without a hope of connecting them or making sense of them. This is also some kind of selection process. Not all possible facts are open to investigation or analysis. Many must be disregarded and the rest are selected. Without such selection, the scientific project itself would not even begin. The facts that will be selected, therefore, are ones that help legitimise the theory which itself is responsible for determining the selection process. It could be said, therefore, that there is a certain circularity involved here. That is, the theory selects the facts to investigate, and those very facts may help to legitimise the theory that is doing the selection.

The above could easily be rewritten in this way:

In politics and history, our point of view is often determined by an ideology. That is to say, we select from the infinite variety of political and historical facts, and from the infinite variety of aspects of these political and historical facts, those facts and those aspects which are useful because they backup and are connected with our preconceived ideologies.

So just as in science, so too in politics and even everyday life, we must in a sense select the facts and bits of information that will help us make sense of the world around us. We cannot be open to the manifold or the infinite. And even if we were, such a state wouldn’t get us anywhere. It would result in some kind of endless list and description of an indefinite amount of facts and bits of information. But what point would that serve? It was just be a glorified list with no practical or theoretical purpose; just as the ‘accumulation of facts’ theory of science is a complete parody of actual science. Something needs to guide us, whether a theory, an ideology, a prejudice, an interest, a bias, or mixture of these.

In the end, we build up a securer and securer ideological edifice. The problem is, of course, that the foundation of this ideological edifice may be insecure because it is based on prejudice and/or falsehoods.

The Laws of Logic

Logical Tautologies

Arthur Pap

Let's look at logical arguments which logicians have called tautologies.


Take


            If q, and (if p, then q), then p.


That is saying that if q were the case, and if p entailed or implied q, then p would have to be the case too. That is, if q then p (in short-hand). In order for q to be the case, p would need to be the case whether or not q is actually the case.


However, we can split the compound


          If q, and (if p, then q), then p.


into parts.


It may well be the case that this implication is correct (or, in its shorter version, that p implies q) even if p (the antecedent) is false. That is, a false proposition can still imply things. It still has implications. After all, the compound formula begins with the locution “If q” and also contains “if p”. In other words, it's an implicational conditional. It tells us what is implied by what even if both p and q are false.

That could also mean that if the antecedent, p, is false, then the entire implication (or conditional) must also be false. That is, if p is false, even though it implies q, then the whole conditional implication must be false.... but wait. In addition, the entire conditional above may be false, and p is false, yet the implied q may still be true!

Clearly it's useful here to distinguish truth from correctness. That is,

      If q, and (if p, then q), then p.

is a correct implicational conditional; though it's not a true one. It's false because p is false, and p implies q. Indeed the conditional is correct (the inference pattern is correct); thought false (one or more propositions are false) even if the consequent, q, is true (when taken on its own).

However, logicians also say that the conditional itself is true (as Arthur Pap does) and not simply correct. Here the notions of truth and correctness are fused. That means that that the overall conditional is deemed true, despite one of its propositions being false. It's the inference pattern that's true. Not necessarily one or all of its propositions.

Here's another tautology:

      If not-q and (if p, then q), then not-p

It's not the case that q is the case. Therefore q is false. However, p implies q. Yet q, as we've said, isn't the case. Thus if p implies something that's not the case (q), then p implies q. Therefore p mustn't be the case either. That is, if p were true, it would imply q. Yet it has already been stated that q is false or not-q. Thus not-q itself implies not-p (though only in conjunction with the parenthesized conditional (i.e., “if p, then q”).

Inferences Involving Classes

Instead of using p's and q's (propositions) in logic, logicians sometimes think in terms of classes instead, as with the Aristotelian syllogism. Take this example:

       i) For all classes AM, BS, and A:
      ii) if all AM are BS
     iii) and some A are AM
     iv) then some A are BS.

Or:

     i) If all African-Americans (AM) have black skin (BS)
    ii) and some Americans (A) are African-Americans (AM)
    iii) then some Americans (A) have black skin (BS).

Illicit Conversion

However, don't make the mistake of illicit conversion. That is, from

     All AM are BS

it doesn't follow that

    All BS are AM.

It doesn't follow that because

      All African-Americans (AM) have black skin (BS)

that

     All those who have black skin (BS) are African-Americans (AM).

Clearly, there are many people who have black skin who aren't also American.

Illicit conversations can happen when logical matters are discussed as well.

For example, it's often said that

     i) All tautologies are formal truths, hence logical truths.

However, that doesn't mean that

     ii) All logical truths are tautologies.

The inversion of “All tautologies are logical/formal truths” is “All logical/formal truths are tautologies” is illegitimate for the simple reason that not all logical/formal truths are tautologies. There is more to logic than tautologies (as against the position advanced in Wittgenstein’s Tractatus).

It other words, it must be said that some logical truths, or inferences (as with mathematics), supply us with additional information (though not facts). Indeed with additional truths.

Here's another example of illicit conversion. Take the statement
 

All logical truths are true by sole virtue of the meanings of their constituent terms (in particular, their logical constants).

It doesn't follow from that
 

All statements that are true just by virtue of the meanings of the terms (hence, that don't require empirical verification and that can't be falsified) are logical truths.

You can't invert “All logical truths are true by sole virtue of the meanings of their constituent terms” and get “All statements that are true by virtue of their meanings alone are also only logical truths”.

For example, the well-known example of


         All bachelors are unmarried.

This is indeed true because the interpretations of its constituent meanings make it true. Nonetheless, the words “bachelors” and “unmarried” are hardly logical in nature. And if they aren't logical in nature, then “All bachelors are unmarried” can't simply be true because of logic (or it can't solely be a logical truth).

Nonetheless, as Quine made very clear, “All bachelors are unmarried” can be made logical; or it can be translated into a logically true statement, simply by writing

       All unmarried men are unmarried.

You don't need to understand what “married”, and therefore “unmarried”, means. All you need to understand are the strictly logical terms: “all” and “not” (or “un”). (Though “are” is not strictly speaking a logical word... then again, in a certain sense, neither is “all”.)

And just as it was said that not all logical, or formal, truths are tautologies, it can also be said that not all necessary, or a priori, truths are strictly analytic. (Of course analytic truths have been seen as tautological too; though this this was largely discounted earlier on.)

Basically, the argument is that some truths are necessary, or can be known a priori, because of the way the world is; or, on some accounts, because of the way all (human) minds work.

Take this example from Arthur Pap:

       No event precedes itself.

This isn't true because of its “constituent meanings” and it's not a tautology (as such). However, it is about world; though it can also be said that one need not consult the world in order to know that it's true. Though surely if that's the case, then how can it be about the world at all? Perhaps the best that can be said that once one gets to know the world (as it were), and one gets to understand and use the words contained in the statement, then one knows that it's necessarily true and that it can be known a priori. That is, it requires previous experience of the world and of language. Yet once that experience and knowledge is in, you don't need to check to see that it's true – indeed that it's necessarily true.

Despite saying all that, the “meanings of the constituent words” can still be said to make it true. After all, once we understand the word “precede”, then it will become clear that an event cannot preceded itself or that x cannot precede x. However, meanings are still important (as they are to most logical truths). Nonetheless, as said earlier, the word “precede” isn't logical in nature.

Defining the Logical Constants

Wittgenstein once said that “some things can only be seen, not said”. This is true of the logical constants. When you define the logical constants, you do so by using other logical constants.

For example,

       All things have property P.

That can be defined as:

      Not-(some things don't have P).

Strictly speaking, “all things” is a use of the universal quantifier (which isn't a logical constant). Anyway, this universal quantifier too is defined by using the logical constant known as negation (or “not-” in this case).

Now take:

       p and q

This is a propositional conjunction which uses the logical constant “and”. It can be defined in this way:

      Not-(not-p or not-q).

To say that both p and q are true is also to say that it's not the case that both p and q are false. Or that “not-p or not-q” is false because both p and q are true. So here a compound proposition which uses the logical constant “and” is defined in terms of the logical constant of negation ( or “not-” in this case).

Finally we have:

      p or q

This is a compound proposition which uses the logical constant of disjunction (or “or” in this case). That in turn is defined in this way:

    If not-p, then q

Here again the constant of negation is used to define another constant. That is, if either p or q is true (though not both), and p is false (or “not-p” in this case), then q must be true because the compound proposition (“p or q”) says that either p or q is true. So if p is false, then q must be true.