(3)
Some of the reasons Berkeley uses to defend his ideas of idealism are the tree falling in the forest bit. Berkeley claims if a tree falls in a forest and there are ears to hear the falling tree, the falling tree doesnt utter a sound. In the same vein Berkeley believed if one was observing say a table, the table ceases to exist. In order to get around what most would consider wack thinking on his part, he uses GOD (the all percieving) to explain away why the table doest pop in and out of existence. How convenient!
Berkeley criticizes Locke's distinction between primary and secondary qualities by stating there is no distinction between the two. That primary qualities are as subjective to our perceptions as secondary qualities.
Berkeley tells us that sensory ideas are derived from a universal mind (God). Which for him explains how different people can basically percieve the world similarly despite the subjectivity created through the lens of primary and secondary qualities.
I dont agree with Berkely's perceptions when those perceptions are challenged he default to the God position which explains and justifies nothing. I can easily imagine Berkeley were he alive today on the forefront of the ID (intelligent design) movement.
(4)
Hume's origin of idea's says that ideas are nothing more than copies of impressions. According to Hume all our thoughts are ideas or impressions. Impressions are sensations, and ideas are memories or imaginings. All of our ideas come to us from previous impressions we've had. Ideas are dim and blurred, but impressions are vivid.
One of the ways Hume distinguished between impressions and ideas was by claiming impressions can be innate, while ideas cannot. He also claimed we can distinguish between the two by the difference of the intensity between both. Such as ideas of memory are more vivid than those of the imagination.
The Copy Principle basically says that every idea is a copy of some prior impression and every impression is copied by some idea is something we can observe. Hume defends this assertion saying that the fact that the impression comes first decides the issue: its the cause and the idea is the effect. One reason for the causal dependence of an idea on impression is that people without the use of one of their senses can never have an idea to that sense. Someone who cant see cant form an idea of red, for example. The belief that impressions cause the existence of ideas was taken by Hume to be central to his treatment of the understanding. "The full examination of this question is the subject of the present treatise" (Book I, Part 1, Section 1).
The missing shade of blue was a story created by Hume to illustrate that its possible for the mind to create an idea without first being exposed to direct sensory experience. If we have a group of colors with a shade missing Hume believes we can form an idea of the missing color by the ideas we already of of the existing colors.
The missing shade of blue is more or less a couter example to Hume's copy principle because in the copy principle if ideas are arsing from impressions, and we have no impression of say the missing shade of blue, how can we fill in that missing shade?
I would agree that Hume's shade of blue is a fair counter example. Our own life experiences informs us that it is possible to fill in that missing shade. We regularly in our daily lives draw conclusions from what we know first hand and then make accurate assumptions about that which we do not seemingly have any knowledge/experience of. If I have worked in a computer related job for a dozen years, then leave that job for a new job still in the computer field, I may not know EXACTLY what that job will entail, but juxtaposing it with my previous experience, I'll have a pretty good IDEA!
