Amadea asked:

Can we ever be said to know anything?

and Sheilla asked:

What are the sources of knowledge?

============

If the answer to Amadea's question is no, then Sheilla's question is immediately spurious. In everyday
terms it would seem rather odd to deny that we could ever know anything. With the assistance of
what we call memory, we are able to identify objects and events made available to us by way of the
senses. Recognition of objects and events can be referred to as knowledge. From this point of view
the source of knowledge is simply the senses. Philosophers who subscribe to such a view are called
'empiricists'.

Some empiricists claim that if there is a deeper source of knowledge beyond the senses, then we can
know nothing about it, because we cannot get beyond the relay system of senses. In other words, we
have no facility to probe beyond the senses to what some imagine to be the 'real' world. The great
German philosopher, Kant, called suspected objects and events in this contemplated real world,
"things in themselves". The best we can hope for with regard to knowledge from this world view are
the representations of the real world made available by the senses, i.e. sense data.

Information given to us by the senses may be understood as 'percepts', things perceived by the
senses. Within this sphere of understanding it is considered that percepts are assembled by the mind
into 'concepts'. These may be regarded as packages of knowledge subsequently stored in the part of
the mind we call memory. Those subscribing to this view consider the total knowledge of each
individual to be made up of concepts.

Materialist philosophers, including scientists, believe that we are in direct contact with the real world.
They also are empiricists who depend upon the senses for information, but the senses in this case
are reflecting the world as it really is. Knowledge from this view is of the real world, not sense
representations. However, such materialists would probably support the notion that knowledge is
made up of concepts derived from percepts.

Knowledge is linked to understanding, the better our understanding the more valid are our concepts.
A three or four year old child asked to draw a tree would be commended for drawing a brown stick
with a green blob on top, this represents his/her concept of a tree. However, a twelve year old
presenting the same image might be rebuked for not trying harder, the general notion being that a
twelve year old should have a more advanced concept of a tree, a better understanding of what is
meant by a tree. Our knowledge can be said to increase by adding more information to our concepts,
expanding them in other words by increasing our understanding of the subject matter of each
concept. Considering knowledge from this point of view, it seems that neglected concepts can fade or
deteriorate, interpreted in everyday language as memory loss owing to lack of interest. The
psychological view is that interest is the bedrock of memory. No interest, no learning. Put another
way, no accumulation of knowledge, no adding to concepts.

Knowledge is associated with truth, we refer to 'true knowledge'. This is compared with belief, which
is a sort of dodgy knowledge, it could be true, but then again it may be false. Theories and
hypotheses are listed under the latter. True knowledge, on the other hand, has access to proof,
concepts or judgements based on true facts is real knowledge. Some philosophers put it another way,
and state that for a proposition to be true it must correspond to a proven fact. Hence propositions may
be true or false. Personally, I do not subscribe to the notion that knowledge is true belief. From my
point of view knowledge is one concept and belief is another, as described above, there is a
distinction between the two. In my opinion 'knowledge is true belief' is a contradiction in terms, and
misuse of language. Admitted there are beliefs which can eventually prove to be true, but we are here
dealing with a different concept.

As you will appreciate, the philosophy of knowledge (epistemology)is a very large and diverse
subject, which has taxed the minds of some of the greatest thinkers. Another philosopher would
probably answer your questions in a quite different way, and possibly disagree with some, or even all,
of my views. Some might answer from an 'Idealist' point of view. Idealists disagree with the notion of a
material world. their world is somehow in the mind in the form of 'ideas'. Such ideas are not to be
confused with the everyday concept of the term, they are far more complex and beyond anything we
can enter into here. However, it follows that Idealists have a different approach to the debate on
knowledge than do materialists and fundamental empiricists.

Then there are the 'Rationalists' who believe that knowledge is available by pure reason. Kant
proposed that our minds are endowed with knowledge which we contribute to our perceived concept
of the world. In a complicated way sense data (percepts) cannot stand alone as knowledge.

I suggest you read A.J Ayer's Philosophy in the Twentieth Century, Unwin: and Bertrand Russell's
The Problems of Philosophy, Oxford University Press.

John Brandon