What is Berkeley's Immaterialism? What are its problems?
Berkeley's Immaterialism or 'idealism' can be examined by first looking at his aims in creating this theory of metaphysics, then by proceeding through the arguments, and finally finding and investigating any problems that may arise. The primary aim of Berkley is to discover a way in which metaphysics can be explained in such a way as to be consistent with the views of a 'plain man'. The main way in which he does this is to deny the idea of 'abstraction', which he feels is distasteful to the 'plain man'. In doing so, however, Berkeley's immaterialism creates a world that is arguably very different to the ordinary, 'vulgar' views of the 'plain man'. The result of immaterialism is that the idea of 'matter' and the external physical world is denied, and our entire worldly experience exists only within our mind. Also, the most famous result of Berkeley's philosophy is the conclusion that 'to be is to be perceived'. The way in which Berkley arrives at this is shown below, and any problems that are found are dealt with as they arise.
Berkeley starts his philosophy with an examination of the senses. He argues that the only things we can be aware of, are 'sensible objects', those objects which can be immediately perceived by the senses. This means that when one looks at a blue chair, then what is perceived is the blue light striking the eye in a certain pattern. Assuming for the moment that there is a material external world, the sense-object that we perceive, is not the extended, solid, blue chair. The structure of this external chair has no 'blueness', the blueness is a state of the consciousness which has been caused by the mind's perception of the chair. Berkeley concludes that the 'proper objects' of the senses can only be of the mind, with no exceptions. Following from this, if the 'sensible objects' that we perceive are of the mind, then we can not claim that there is an external world.
It can be seen that this argument is not a disproof of the external world of matter, it simply claims that the hypothesis of a material world is not reasonably grounded on anything knowable. Berkeley, however, does go on to attempt to actually disprove the material world, by investigating the idea of 'matter', and finding that it is not possible for matter, as it is commonly known, to cause sensation. As matter is fixed, passive, and not 'immediately sensible' - it has already been discovered that 'immediately sensible' things are the 'proper objects' of the senses, and only exist in the mind - and it is inconsistent for a fixed, passive unknowable thing to create ideas in the mind, then matter does not exist as we know it. Berkeley would state it in such a way as to define matter as we know it unperceivable, and for matter to exist is not consistent with the existence/perception conclusion mentioned above.
After he concludes that matter does not exist - we exist in a universe of spirit - we are left to investigate the problem of ideas, and their relation to the mind. To begin with, it must be stressed that by the term idea, Berkeley is not referring to an abstract idea, such as a 'form' or 'essence'. This type of idea cannot exist with in Berkeley's universe, as it is impossible to form such ideas. For example, an abstract idea or 'form' of the table before me is based upon many different sensory impressions, which are somehow distilled and refined to create a supposedly accurate 'idea' of the true nature of the table. In Berkeley's world, there is no way to distinguish between the different views of the table, in order to decide the true nature of the table; Berkeley claims the true nature of the table is the sense-data which is perceived by the mind. This move by Berkeley has important consequences, as by removing abstract ideas, a question arises in how we can make sense of the world around us - if all we have for ideas are fleeting, and non-permanent, how is it that we can have knowledge that seems connected or continuous. This problem is answered at a later point in the essay, when the concepts of the role of God and causation are examined.
Much has been discussed about the relationship between the mind and ideas in Berkeley's philosophy. In his writing, Berkeley states both that the mind and its ideas are distinct, and that the perceiving of and idea is indistinct from the idea perceived. Commentators have found that it is possible to find a contradiction in these two statements, as for both to be consistent, it must be agreed that the mind does not perceive ideas. This, however, is absurd, and so it is the other two statements that must somehow be reconciled in order for Berkeley's philosophy to stand. The difficulty in doing this stems from the fact that the perceiving of an idea is an act of the mind, and in order for the two statements to be compatible then it must be agreed that and act of the mind is distinct from the mind itself. In order to do this, the 'distinctness' that Berkeley claims is between the mind and its ideas is of the rather weak form, such as a swimmer is 'distinct' from his breaststroke. The first of the two statements above, therefore, must be read in a weaker sense than is immediately obvious.
Another question that is raised by Berkeley's concept of ideas is the question of whether or not it is possible for two people (or minds) to have the same idea. As Berkeley claims that all our ideas are the sensory perceptions, and it is impossible for two people to have the same set of sensory perceptions, then it is equally impossible for two minds to have the same idea. This seems to be difficult, as it is seeming to imply that two people sitting on opposite side of a room see different chairs, although there is only one chair between them.
Similar to this problem is the question of whether or not a thing still exists when it has stopped being perceived. From the arguments which have been heard so far, the answer would seem to be that since we have no immediate sensory perception of an unperceived object, then there is no reason to suggest that it remains in existence. This is a common criticism of Immaterialism - that it is arguably possible for an unperceived object to exist. Berkeley's reply to this objection starts with the assertion that it is impossible to give any example of an unperceived object, for to do so, one must conceive of it in one's own mind. If it is conceived in one's own mind, then it is the perception of this object which is being conceived, therefore making the unperceived imagined object perceived. In simpler terms, In trying to state an example of an unperceived object, one must imagine oneself perceiving the object in order to comprehend it. Also, the denial of anything abstract promptly disallows any theoretical unperceived object. It is still felt, however, that this is not a very satisfactory answer to the question of existence under Berkeley's Immaterialism.
It is at this point Berkeley introduces his theories of the role of God. He claims that it is evident that ideas do have some form of consistency and continuity, and therefore there must be an eternal, omnipresent being that is all-perceiving. Berkeley uses God to explain many a problem with his philosophy. For an idea-object to exist it must be perceived by God. The only necessary requirement for existence in Berkeley's philosophy seems to be that the object is perceived by God. The role of God is a very important one, and without it, many of his assertions can not be made. Curios, then, that he only brushes over attempting to prove the existence of God. Without this proof, all of Berkeley's philosophy takes on a very circular property. Before examining this circularity, the tasks that Berkeley's God undertakes shall be investigated.
Not only does God ensure the existence of all things when not being perceived by one's own mind, God also makes it possible for two minds to have the 'same' idea. This is due to God's role in causation. It can be seen that the ideas we have are simply a state of consciousness, and we can have no awareness of anything that is outside of our mind, then it is impossible that either the idea, or our own, passive, mind to cause the 'same' idea in any other mind. It can be seen, however, with the existence of an all-perceiving God causing the ideas in our mind, that the same cause could produce a similar idea in another mind. This looser sense of the word 'same' makes it possible to refer in everyday language to two people having the same idea, which is necessary in order for humans to understand each other.
It can be seen, then that Berkeley's philosophy relies heavily on there being an omnipresent, all-perceiver. If there is not, then it is difficult for him to make the claim for the continued existence of the continued existence of unperceivable objects, or the claim that two people could have the 'same' idea. Indeed and more importantly, without Berkeley's God, there is no reason for the world not to be thrown into chaos, and is his this God which ensures the laws of nature are obeyed. Furthermore, without a solid proof of the existence of God, Berkeley's argument seems circular. Gods existence can be seen from the non-chaotic nature of the universe, and the non-chaotic nature of the universe is due to God's existence. This seems to be the underlying flaw in Berkeley's Immaterialism, the inability to properly show either the existence of God, or the non-existence of matter without requiring God's existence.