Theory of knowledge

Knowledge may also be said to consist of such observations and conclusions that many persons openly investigate, revise, alter and maybe agree about. This type of knowledge is an adaptation to that "eternal truth" cannot be shown to exist.

For this knowledge to be trustworthy, it is important how it is spread and revised:

•  What type of arguments can be used?
•  How can revisions be encouraged?

From the answers to such questions, something that reminds about what we today call scientific method will probably be created.

As discussed above, the term "knowledge" is not easy to define, and within philosophy this invites to speculation.

A question discussed since the Greek antiquity is whether "knowledge" should be based by observations or if we may reach "knowledge" using only logical reasoning, independent of observations.

Plato discussed that our observations cannot be proven to represent some kind of reality and Aristotle stressed the importance of observation together with logical reasoning (deduction). They both actually had about the same opinions.

And so it has continued through history of philosophy.

During the Enlightenment the concepts became more defined and e.g. David Hume called the two groups, from which our reasoning are built, for "matter of fact" and "relations of ideas".

Reasoning based on "matter of fact" was called probability arguments. Western philosophers today agree about that our experience about the world is ultimately based on such arguments.

It is generally agreed that tautologies ("analytic arguments") represent reasoning a priori. But does arguments in addition to these ("synthetic arguments") exist that also can be said to be a priori?

That is: Does arguments a priori about our experienced reality exist? Without such arguments, the relevance of pure analytic philosophy (armchair philosophy) concerning the world can be seriously questioned.

Kant enters the scene

Without defining his use of the term "knowledge", Immanuel Kant discussed these topics in terms of "a priori" ("knowledge" that can be justified without referring to observations) and "a posteriori" ("knowledge" that requires observations for justification). What he claimed to be a priori arguments is at this website called "absolute knowledge"

Immanuel Kant (public domain)

Kant wished that abstract philosophy should be justified, and with the help of diffuse definitions he claimed existence of "synthetic a priori arguments".

He hence claimed existence of statements about the world that are not ultimately based on experiences or, differently expressed, that combination of "absolute knowledge" about the world is possible.

A quick conclusion learns that in case we cannot claim existence of any "absolute knowledge" about our world, it is of course impossible to claim existence about combinations of such knowledge. Philosophes, however, dislike quick conclusions. Below three example of longer texts with a similar final conclusion:

• Boghossian P, Peacocke C - New Essays on the A Priori, Clarendon Press (2000).

• Kitcher P, "A priori", Ch. 1 in Guyer P (Ed) - Kant and Modern Philosophy, Cambridge Univ. Press (2006).

• Andersson, H - Apriorisk kunskap, en analys av definitioner, C-uppsats, Lunds Univ. (2007).

Definition of induction:

The process of inferring a general law from the observation of particular instances

Oxford English Dictionary

Short version: Inferring from particulars to generals.

A philosophic attitude that argues for the use of induction is called empiricism.

Induction implies that repeated similar observations create expectations of that additional similar observations under similar conditions will yield similar results, and that they therefore represent something general.

Or in everyday language: When we note something several times, we believe that it is true.

We use induction every day, possibly in every conscious moment. Every morning, we expect the world to look similar to what is was in the evening before - induction! We drink a glass of water and expect it to quench our thirst - induction! We drop a heavy stone and expect it to fall - induction!

We believe that we should look approximately the same and that the floor remains. Induction is the base for all our experience.

Another example of induction is that we believe that every human someday, sooner or later, will die.

Neither induction nor any other method will give rise to "absolute knowledge". Regardless of how many observations we have performed that support a hypothesis, we cannot be certain about that the hypothesis is "absolutely true". This was discussed e.g. by Sextus Empiricus about 200 AD and by Isaac Newton 1730:

It is easy, I think, to reject the method of induction.

For since by way of it they want to make universals convincing on the basis of particulars, they will do this by surveying either all the particulars, or some of them. But

- if some, the induction will be infirm, it being possible that some of the particulars omitted in the induction should be contrary to the universal, and

- if all, they will labour at an impossible task, since the particulars are infinite and indeterminate.

Thus in either case it results, I think, that induction totters.

Annas (Ed.) (2007) - Outlines of Scepticism, Book 2, part XV

As Sextus Empiricus was an advocate of empiricism, it is likely that the term "induction totters" for him implied a rejection of that induction could give rise to "absolute knowledge".

And although the arguing from Experiments and Observations by Induction be no Demonstration of general Conclusions; yet it is the best way of arguing which the Nature of Things admits of, and may be looked upon as so much the stronger, by how much the Induction is more general.

Isaac Newton (1730) - Opticks, 4Ed, p.380

An illustration of the problem with induction was given by Bertrand Russell:

There was once upon a time a census officer who had to record the names of all householders in a certain Welsh village. The first that he questioned was called William Williams; so were the second, third, fourth, ...

At last he said to himself: "This is tedious; evidently they are all called William Williams. I shall put them down so and take a holiday."

But he was wrong; there was just one whose name was John Jones. This shows that we may go astray if we trust too implicitly in induction by simple enumeration.

Russell (1945) - History of Western Philosophy, in the section about Francis Bacon

Scientific methodology decreases the insecurity inherent in induction. A scientific treatment of Russell´s illustration may look like this:

• The census officer publishes that all were named William Williams and how he reached this conclusion.

• Somebody reads this and notes that the work is not complete. She checks the church books and finds one John Jones. She reports this, how she arrived to this result and also describes the earlier work by the census officer.

• A person in the village reads this second report and knows that the neighbour, a recent immigrant, is called Sven Svensson. This is reported as a "letter" to a journal. This "letter" also contains references to the two previous reports.

In this manner will, by and by, through induction, verification, falsification and publication, a more refined description of the householders in the village be developed.

Definition of deduction:

The process of drawing a conclusion from a principle already known or assumed

Oxford English Dictionary

Short version: Inferring from generals to particulars.

A philosophic attitude that argues for the use of deduction is called rationalism. It is popular within philosophy and is sometimes called "armchair philosophy"

A problem with rationalism is that strict deduction, without references to observations, cannot give anything of interest regarding our perceived reality.

Or differently expressed: Arguments that are synthetic a priori have not been demonstrated to exist. This was discussed in detail by David Hume already at the eighteenth century.

A form of rationalism that is possible to apply while describing our perceived reality therefore must include empiricism.

A more illuminating definition about deductive arguments concerning our perceived world accordingly read:

Deductive arguments concerning our perceived reality create relations between conclusions (ultimately based on perceptions) and perceptions, or between conclusions (ultimately based on perceptions) and conclusions (ultimately based on perceptions).

The link to the definition in Oxford English Dictionary is provided by that "a principle known or assumed" is ultimately based on perceptions.

The logical impossibility of strict rationalism was also discussed by Bertrand Russell:

German philosophers, from Kant to Hegel, had not assimilated Hume's arguments.

I say this deliberately, in spite of the belief which many philosophers share with Kant, that his "Critique of Pure Reason" answered Hume.

In fact, these philosophers, at least Kant and Hegel, represent a pre-Humian type of rationalism, and can be refuted by Humian arguments.

Russell (1945) - History of Western Philosophy", in section about David Hume

• Do we know anything?
- Probably.

• Can we prove that we know anything?
- No, not if the term "know" is taken to mean "absolute knowledge" (but this does not imply that we do not know anything).

• Can we live with that we cannot prove that that we know anything?
- Obviously.

After having written this summary, I became aware of that David Hume formulated the last point in a far more poetic manner:

...who must act and reason and believe; though they are not able, by their most diligent enquiry, to satisfy themselves concerning the foundation of these operations, or to remove the objections, which may be raised against them.

Hume (1777) - Enquiry, p.160