Glenn asked:

How is it possible for George Berkeley to be a subjective idealist yet be considered one of the great
British Empiricists? How can you be both an Empiricist and idealist at the same time? Or, how can an
idealist be an Empiricist?

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Several kinds of Idealism are distinguished in philosophy. Idealism, very basically, is a belief that the
world we see around us is somehow created by our mind.

Berkeleian Idealism (sometimes called Immaterialism) says that what we call a 'material object' is
really just a collection of ideas (in a very broad, non-technical sense of the word 'idea'). Berkeley
would not normally be called a subjective idealist, because he added that the ideas that make up
'material objects' exist permanently in the mind of God — which gives them an existence independent
of perceiving subjects.

Berkeley was arguing against the notion of 'material substance' which John Locke made use of in his
Essay concerning Human Understanding.Influenced by developments in science, Locke claimed that
some qualities of objects (e.g. colour, smell) only exist when we observe them, but that other qualities
(e.g. shape) are really part of the objects, whether anyone is observing them or not. Berkeley reacted
to this by arguing that allqualities can equally be said to arise only when we perceive them. Things
can only be described in terms of our perceptions of them — their texture, smell, sound, taste or
appearance.

Two other kinds of Idealism are commonly distinguished:

*Kant's Transcendental Idealism — the view that the things we perceive as existing in space and time
are appearances shaped by the structure of our sense-organs and brain. This is called subjective
idealism because the perceiving subject influences what is perceived. Kant also claimed there must
be things 'as they are in themselves' (noumena), which are the source of our perceptions — even
though we can never know anything about these.

*Absolute or Objective Idealism — the view of Bradley and Hegel, among others, says that only one
thing really exists; a kind of Universal Mind/ Spirit ('the Absolute').

As for Empiricism; along with Locke and Hume, Berkeley maintains that all our knowledge is
ultimately derived from what we have taken in through our senses. This is true even though he talks
so much about ideas: those 'ideas' includeperceptions (sights, smells, sounds etc.)

Katharine Hunt

This is a good question. Empiricists think that all knowledge comes from sense experiences alone,
experiences called 'ideas' according to Locke and Berkeley or 'impressions' according to Hume. This
gave the empiricists a huge problem, believe it or not, concerning the existence of 'substance' or
'matter'. If all human knowledge proceeds from the 'ideas' received through the senses, then do we
ever sense matter? Here is a postcard version of what Berkeley says in the Principles of Human
Knowledge:

*All we perceive are ideas.

*We perceive objects.

*Therefore, objects are ideas.

Berkeley thinks that the non-existence of material objects is consistent with what we are aware of,
that matter itself would not explain our ideas without a causal account of how they act on our minds.
So Berkeley thought that matter is 'unintelligible' for the reason that trying to imagine matter apart
from the qualitiesthat it possesses (shape, colour, hardness etc) results in you thinking about nothing
at all. Locke — certainly a materialist among the empiricists — held that substance is a 'know not
what' support of the qualities we pick up through perception. Materialists think that matter lacks all
visible qualities; so Berkeley, following ruthless logic, simply says that imagining matter is impossible,
as invisible and propertyless stuffis just too austere and remote from the world of experience.
Berkeley's position is motivated by epistemological considerations, and is surprisingly intended to
defeat skepticism. A full version of his argument can be found in the Principles of Human Knowledge
§18 ff.

*How could you know matter exists?

*It must be by sense or by reason.

*Everyone agrees that it is not by sense, so it must be by reason.

*It is conceivable that we should have the same ideas without the existence of matter.

*Therefore there is no good argument of reason for the existence of matter.

The materialist response is that our ideas are best explained by supposing them to be cause by
material objects. Berkeley replies by saying that materialists have no explanation of how bodies act
on minds, so if there were bodies, it is impossible that we should know it.

This argument illustrates one of the skeptical conclusions of empiricism, that if all our knowledge is
via the senses and there is no sensory impression of matter, it must be true that we know nothing
about matter. It follows furthermore, that it must be imaginary that there is such a thing as matter, and
it must also be superfluous when we try to make sense of the world. This is common sense, Berkeley
argues. Why suppose that something you don't know anything about is the best explanation for way
things seem. Berkeley's position, most interestingly of all, is an attempt to avoid the skepticism about
the world in which the logic of empiricism results. Talking about that would be the answer to another
question, but see if you can begin to think through why Berkeley claimed his position avoids the
skeptical results of full throttled empiricism!

Adam Gatward