What is truth?  How do we, or can we, as human beings, really know what is true, or not true? 

Or what is knowledge?  How do we, or can we, as human beings, really claim to know anything at all?

And if something is known to be true today, how can we know if it will still be true tomorrow?  Was it always true in the past?  How can we know this?

These questions of the nature of truth and knowledge are intimately related to each other.  The study of these questions is called epistemology (from the Greek, 'episteme' means 'knowledge').  It is a notoriously challenging and tricky issue that transcends almost all other issues or questions in the field of philosophy.  It is critical importance to the field of modern science as well as the issue that essentially defines 'religion' as distinct from 'philosophy'.

I shall undertake in this thread to give a basic outline of the essential principles and key elements of this issue. 

Warning: Please fasten your seatbelts and put away all dangerous objects.  In this thread you are likely to encounter the old 'tree falling in the forest question' as well as Schrödinger's cat, Bishop Berkeley, solipsism, Descartes' radical doubt, Kant's first principle, Hume's rational (and extreme) skepticism and a whole whack of other stuff that may cause brain damage, headaches, frustration or other side effects.

* * *

Cogito ergo sum.  I think, therefore I am.

That's the beginning and that's all any given human being can really and truly know.  That's it, that's all.  Due credit goes to Descartes for this brilliant and elegant statement.  Beyond this point, anything and everything can be reasonably and rationally doubted - but the one thing "I" truly know is that "I exist" - as for anything else, I'm not so sure.

I am some conscious thinking being - seeming to float or reside inside a human-type body.  That's all I know.  I have lots of sensations coming at 'me' from my eyes, my ears, my nose, my imagination, my fantasies, my mind's eye or whatever you will, but what does all this stuff mean?  It is all real?  If I see other human shapes out there, are they other beings like me or are they just figments of my imagination?  Maybe some are and some aren't?  How can I know the difference?

Solipsism

Maybe, all those sensations that "I sense" are all just figments of my imagination?  Maybe, I'm the only conscious being in the whole universe and there is some super omnipotent God out there that is creating this grand delusion in my dreams and imagination?  It is possible that nothing outside my own conscious being is real.  Absolutely nothing except the omni-God doing the grand delusion thing.  Anything is possible, or nothing.

This is one school of thought in the field of epistemology.  As a logical argument, it cannot be generally refuted.  I draw attention to it here as a 'lesson' or reminder about the tenuous intellectual ground we presume to stand on when we presume to speak about 'knowledge' in any serious or philosophical way. 

Faith

Bishop Berkeley famously uses the solipsist argument to argue that one rationally has no choice in the matter but to put trust or faith in God's essential goodness.  Ultimately, Descartes own argument leads in this same direction - a need to trust God in order to make sense of everything.  Both of these are essentially just acts of pure faith.  Under this model, truth or knowledge is, by definition, God's will.  This logically means that as a human being, my faith in God is the absolute definition of what is true and/or what can be known.

First Principles

Immanuel Kant, in his study of these questions asserted an alternative to 'pure faith in God's goodness' as a rational basis for knowledge.  Kant postulates a belief in the reality of a time-space continuum existing independently outside of his own conscious being.  This is Kant's First Principle.  It is an act of faith no different than that of 'faith in God's goodness'.  However, it does provide an objective standard against which one's own senses, perceptions, thoughts and imaginations can be measured against or compared to, as a method of making sense of the world (independent of pure faith in God's goodness).   

It is important to note here that Kant's First Principle is necessarily a unique event.  This act of faith is justified because it a necessary act of faith if one seeks a rational basis for claiming knowledge (the only alternatives are solipsism or blind faith in God's goodness).  No additional act of faith is justified here by the establishment of this First Principle.

On this basis, humans can and do make claims of knowledge.  That which can be physically shown to be consistent with the measured facts of the time-space continuum are held to be 'true' and those that are not consistent to the measured facts of the time-space continuum are held to be 'not-true'. 

Modern Science

Scottish philosopher David Hume famously argued that one cannot know that the sun will rise again tomorrow, one can only assume it will, based the historical track record that the sun has risen every day in the past.  One could use telescopes and calculations to show that it is extremely likely that the sun will rise again tomorrow, but the bottom line is still that one cannot absolutely prove that it will.  The sun could possibly blow up between now and then. 

The key point here is that our modern science is cognizant of this issue of epistemology - it is integral to the enterprise.  Our scientists never say they have the answer to anything.  They only say "to the best of our knowledge, at this time, according to this data, we believe this to be true".  It is a fundamental principle of modern science that they have no absolute answer to anything - only a tentative understanding that is temporal and subject to change as new data becomes available.  This is why gravity is still held to be a 'theory'.  It stands as a 'dominant' theory until it becomes disproven.

So that's my brief survey/introduction to epistemology.  There is no single answer to the question.  But most of modern philosophy, and all of modern science, follows from Kant's first principle.  All existing religions, by definition, ultimately fall under the rubric of 'pure faith'.  This tends to divide religion from the rest of philosophy and science.

I can and will go on to show how all this impacts the issue of truth and the infamous problem with 'facts' and trees falling in forests, but I'll wait to see if anyone is interested to proceed or if any of what I've said so far needs further explication. 

That may well be true for the field of mathematics generally or probability science particularly, but that's beyond my expertise.  I'm not a math-guy.

(Btw, although I started off as a bit of a precocious 'math whiz' in grade school, I most certainly did not like it - I've always preferred to study people rather than numbers) 


I am impressed that you are doing homework "on this". 

Anyway, I'm not aware that anti-inductive reasoning is anything but a 'thought-example' used as a possible counter-argument to Hume's reasonings about the nature of inductive reasoning.

Besides, it is one of those things (like solipscism) that seems just too clever by half (and tends to give academic philosophy a bad reputation).  But intellectual discipline does require one to consider the merits and these ideas certainly are very difficult to rationally refute or reject.  That is what philosophy really is all about - coming to grips with all of these ideas - there really is no right or wrong answer to anything, as long as it is well reasoned, it must be considered 'possible'.

As I noted in some other threads, from the perspective of pure rationalism, or for the study of philosophy, the question of the (non-)existance of God is mostly irrelevant in those particular terms. 

All that is generally of concern to philosophy is the human profession of (non-)belief in the existence of God.  Humans are a valid topic of reasoned philosophic study - Gods are generally not.  One's belief in God is something that can be discussed, or addressed, or is meaningful - questions of God's actual theoretical existence are much less so. 

This thread is meant to demonstrate the reality of philosophic questions that do indeed take philosophical 'primacy' above the religious concern for God's theoretical existence.
 

No, and I never said they were.

I suppose I'm being pedantic, but that's a common thing in philosophy.

The question of God's existence is irrelevant since God (or Gods), if they exist, are outside the realm of human knowledge.  Its not that this question isn't important, it is that this question cannot be rationally answered either way.  As such, the question is just a religious battle for converts (or pure speculation).  That has nothing to do with philosophy and everything to do with religion.

Dormouse-

Your brief introduction into the history of epistemology demonstrates to me that we take a lot of things based on faith whether it's the existence of God or sensual correspondence with reality.  The only PURELY logical position is solipsism.  Cogito ergo sum and nothing else because it is all I know.  It requires no faith.

And yet, I think that anyone who considers himself a solipsist to be off his rocker.  G.K. Chesteron once wrote "The madman is not the man who has lost his reason. The madman is the man who has lost everything except his reason." 

Both Descartes and Kant took a step beyond pure reason in their faith-based assertions.  The logic can only take us so far.  An answer to the question of Gods existence must be asserted once the foundation of epistemology has been layed.   Without an answer to this fundamental question, we do not have the necessary framework for contingent philosophies (i.e. morality, origin of the mind, etc.). 

There are several other "religious-themed" threads in this sub-forum that are begging for one's religious opinions regarding God's existence.  This isn't one of them.

If you follow Kant's reasoning, God's existence stands entirely outside the realm of human knoweldge (by definition).  Ergo, questions about God's existence have no place in philosophy.

The term "atheist" originates (in usage) as a slur favored by religious types to use against their political enemies (circa 16th century).

According to Wiki (or the OED) it is not until the 18th century before any 'positive' usage/affirmation of the term is found.  Until that time, the term existed as a religious slur alone. 

Indeed, the 'positive' usage of this term is almost entirely identical to the way homosexuals have co-opted the term "fag" and Afro-Americans have co-opted the term "nigger" - turning these slurs into a badge they choose to be proud of.

Philosophy is NOT the search for truth. 

If that were true, then we'd be talking about 'aletheisophy' instead of 'philosophy' as that would be the proper term for the study or search for truth. 

As I've noted previously and repeatedly, philosophy is a search (or love) of wisdom.  It is a religious conceit to just assume that "wisdom" means "God" by definition.  It might, or it might not. 

According to the reasonings of epistemology, God's existence (or not) is a matter that categorically resides entirely outside the realm of human knowledge.  Philosophy is properly concerned with human-based knowledge - it is human subjective by definition.  Ergo, God's existence is not a relevant question of analysis in philosophy because the existence of God(s) are not subject to any consistent rule of human reasoning, human rationality or human logic.

The search for (or love of) truth is essentially the practical definition of religion (holding that truth is synonymous with God's truth).