One might imagine that Berkeley believes in a Universe containing objects which only spring into existence the instant a consciousness sweeps over them, and then, once the perceiving consciousness has passed, they disappear again. Or perhaps, one could assume that Berkeley believes that all objects continue their existence because, you know, God is always watching. But what Berkeley is contending about the Universe is actually something more complex…
Berkeley states that all the objects we think we see in the world are our own Ideas projected outward. He asserts that the most fundamental aspects of what we think of as Reality– things such as Extension, Figure, and Motion– exist only in the mind as “Ideas.”
For example, consider the our perceptions of Extension and Figure. With adequate perception and tools, the extension of any object can be halved, and halved again, and on and on. Berkeley contends that if our senses were rendered more and more acute, we would be able to see a greater and greater number of parts in whatever object is under observation, until it “shall seem infinite.” Therefore, every object would necessarily contain within it an infinity. And if every object is an infinity, it is “consequently void of all Shape or Figure” (since Shape/Figure is only created by the presence of a containing boundary). Therefore, it seems clear to Berkeley that it is the mind that frames all objects, and gifts them with Figure and Extension (a.k.a, Shape and Size).
We can see how this would also mean that Motion can have no objective reality since velocity is dependent upon distance-covered, and Berkeley has now led us to abandon the idea of objective Extension. Furthermore, it is arguable whether another component of Motion, “Direction,” means much in a Universe filled with infinities.
Extension is also intricately bound-up with Number, as Extension, to be measured, must be denominated in units of some form or another. However, says Berkeley, the same body “bears a different denomination of Number as the mind views it with different respects.” For example, “the same extension is one, or three, or thirty-six– according as the mind considers it with reference to a yard, a foot, or an inch.”
“Number,” declares Berkeley, “is so visibly relative, and dependent on men’s understanding, that it is strange to think how anyone should give it an absolute existence without the mind.”
Compound Ideas And The Conception Of The Abstract
So much for the Simple Ideas of: Extension, Figure, Motion, and Number. The mind, however, does not deal only with Simple Ideas, but with mixed or concurrent Ideas which Berkeley calls “Compound Ideas.” For instance, when we believe we perceive an object with shape, size, and color… we are experiencing a Compound Idea.
The Human Soul or Spirit not only experiences Compound Ideas as “perceptions” but through the imagination. Berkeley contends that, as a human being… “I have a faculty of imagining, or representing to myself, the ideas of those particular things I have perceived, and of variously compounding and dividing them. I can imagine a man with two heads, or the upper parts of a man joined to the body of a horse. I can consider the hand, the eye, the nose, each by itself abstracted, or separated from the rest of the body.”
This ability to entertain Compound Ideas via the imagination leads directly to the Human Spirit’s ability, or purported ability, to entertain “Abstract Ideas” arrived-at by “retaining only what is common to all” within a certain category or type. For example, it is maintained by some that we can speak of “Man” in the abstract without having in mind any particular man.
However, Berkeley does not believe that the Human Mind is capable of truly imagining the Abstract. For example, we cannot imagine some Man-in-the-Abstract without imagining him with attributes typically common to Man, such as hands and eyes. “But,” writes Berkeley, “whatever hand or eye I imagine, it must have some particular Shape and Color.” Likewise, if we attempt to think abstractly of a Color, we find that we cannot conceive of it without Extension of some degree. The same goes for any attempt to think of some abstract idea of Motion. We cannot conceive, writes Berkeley, of “an idea of Motion without a body moved, or any determinate Direction or Velocity.” Similarly, he states that we cannot conceive of “an abstract general idea of Extension, which is neither line, surface, nor solid, neither great nor small, black white, nor red, nor of any other determinate color.”
“I desire anyone to reflect and try whether he can, by an abstraction of thought, conceive the Extension and Motion of a body without all other sensible qualities. For my own part, I see evidently that it is not in my power to frame an idea of a body extended and moving, but I must withal give it some color or other sensible quality” […] “In short… extension, figure, and motion –abstracted from all other qualities– are inconceivable”
Berkeley cites for an example one of the simplest of all abstract ideas, the triangle… We can easily enough define the triangle as “a plane surface comprehended by three right lines”-– but, states Berkeley, we still don’t know “whether the sides are long or short, equal or unequal, nor with what angles they are inclined to each other.”
It is not that Berkeley believes that we can’t think in general terms. Only that — since it is impossible to consider objects without giving them Extension, Color, etc– it is therefore impossible for us to imagine Abstractions (once an object takes on a specific physical characteristic, it is no longer Abstract, as Berkeley is using the term). “I do not deny absolutely that there are general ideas,” he writes, “but only that there are any abstract general ideas.”
Personally, I don’t feel that Berkeley differentiates enough between “abstract” and “general” ideas. However, what I came away with from Berkeley here is a renewed conviction that we must be extremely wary philosophers– or an politicians or anyone else– starts talking in abstractions or generalities. For instance, when things are claimed to be bad or good for “Society”– we must remember that Society is a mushy term, that– as an abstraction or generality– it both exists and does not exist… We all have an idea what is meant by “Society”– but there is not precisely defining or measuring it, and those who argue that: there is no Society, there are only individuals– there is some truth to what they are saying. As a general rule, any statement using an abstraction or generality is to be considered weaker and more suspect than statements based upon specifics.