Does Perception Affect Reality? - Berkeley's Idealism - Dialogue 1 from "Three Dialogues Between Hylas and Philonous"

In these excerpts from Berkeley's work "Three Dialogues Between Hylas and Philonous" we are able to see the philosophical Idealism of Berkeley. It is clear that his characters are following the axioms of Cartesian Rationalism, with truth beginning in the mind rather than in things. Given this, the two of them argue back and forth over the possibility of knowing a world outside the mind. The conclusion that is reached is that all one can know are perceptions generated by the mind and ideas, or "archetypes," which exist in the mind. All that can be known to exist then is that which is being perceived by minds, leading to the idea that "to be is to be perceived," for one cannot know the continued existence of what one is not currently perceiving (again, for a Rationalist...). Berkeley, like Descartes, will have to throw a lifeline to God to be the one who guarantees the veracity of experience, as the individual mind cannot do this on its own. Clearly one can see where accepting the premises of Rationalism is going to lead, to solipsism ... and ultimately to the philosophical skepticism and anti-rationalism in the 19th Century. 

Another point that is brought up is over the nature of what "matter" is. It seems clear that Berkeley is clearly drawing upon the paradoxes of Zeno in order to put into question the reality of what "stands under" perceptions. If our perceptions of material things can continually be subdivided into smaller units, on to infinity, does anything really lay at the foundation of matter? Aristotle will answer this through the necessity of immaterial forms existing at the core of material being, but since Berkeley starts from the position of the mind, it doesn't seem possible to reach "things-in-themselves." 

Excerpts from Three Dialogues Between Hylas and Philonous

What is "Matter?"

The dialogue is between two men, Hylas and Philonous, regarding the nature of matter ... or the lack thereof. Beginning, Philonous makes the bold claim that there is no material world which exists in itself. 1 Hylas makes the point that such a claim just goes against common sense, and so why should he hold such a view? Philonous responds that it is actually Hylas, and those who belief in the existence of "matter," that are the skeptics and act against common sense. Thus, the impetus for their dialogue sets them into conversation. 

In their discussion Hylas admits that he is beginning from the premises of Rationalism in that he is a "thinking thing" which is experiencing sensations of things, but is hard for him to accept that there is not some type of material substratum of being which is at the core of what he perceives. Philonous challenges him regarding this, asking if he really perceives a material substratum, or only its "modes and qualities?" Is it not the rational mind which understands the idea of the identity of the thing? Hylas responds that, true, he may only sense the accidents of the thing, but don't they have to exist in some material substance? But, if that is true, then doesn't it mean that we only have an idea of the thing based on its changing accidents? And what would be the relation then between the accidents and the substance of things? 2 

Philonous makes the point that to "stand under" the accidents is to be at the same time distinct from the accidents, and yet be the cause of the existence and spreading of those accidents? Therefore the material substratum must itself have some extension distinct from the extension we are currently talking about. But this would have to go on to infinity as one breaks down one thing into something more fundamental to get at its material substance, but then break that down to something more fundamental, and so on and so on. 3 "Philonous: Consequently, every corporeal substance, being the substratum of extension, must have in itself another extension, by which it is qualified to be a substratum: and so on to infinity. And I ask whether this be not absurd in itself, and repugnant to what you granted just now, to wit, that the substratum was something distinct from and exclusive of extension?" 4

Philonous Asks If We Even Know Things Outside Perception? 

Philonous jumps on Hylas, then, and points out that Hylas doesn't actually know what "matter" is at all. All that one can know are the accidents that one senses, not what, if any, substratum exists beneath them. Rather, Philonous claims that these perceived accidents depend for their existence on the mind of the perceiver, not on some inherent substance. Indeed all our perceptions of the world are through "secondary qualities" which seem to depend on the mind, such as the perception of color, temperature, movement, etc. 5 "... I am content to put the whole upon this issue. If you can conceive it possible for any mixture or combination of qualities, or any sensible object whatever, to exist without the mind, then I will grant it actually to be so."

But, Hylas continues, isn't it common sense that things exist on their own, independently of our seeing them? While this may seem obvious, Philonous points out that we don't actually know that, as if they are not seen, then they are not seen. We only know they exist by the perceptions we experience in our mind. Whether things are near or far, clear or unclear in terms of sight, 7 it is still true that it is the mind which understands what's there in the perceptions. Even if distance is involved, things are still what they are. In fact, even distance itself in a type of idea understood by the mind. 8 "But, allowing that distance was truly and immediately perceived by the mind, yet it would not thence follow it existed out of the mind. For, whatever is immediately perceived is an idea: and can any idea exist out of the mind?" 9 Regardless, everything perceived is either a perception generated by the mind or an idea recognized by the mind. 

They continue along the same lines about a statue of Caesar, Hylas claiming that in seeing the statue he also sees something then beyond the perception of the statue. Philonous fires back saying that this is not the case. One can see the physical appearance of Caesar and see a picture of Julius Caesar and have the same perceptions equally. Everything that is known of him is either perceived, or thought about as an idea, or retained in memory. There is nothing about him beyond the experience of perceptions which one knows. 10 

The only exception that Philonous admits is that we begin to form memories and connections of sense perceptions such that we may expect one to follow another, which may not actually be the case in reality, but this doesn't contradict his beliefs. Hylas eventually gets back into a corner and simply says that as long as there is a possibility that material things exist of their own accord outside the mind, then he will believe it. This gives excuse for Philonous to go on the attack and to show that there is not even a possibility. 11

Philonous Claims That All That is Known Are Ideas and Perceptions

Philonous says that if our ideas are based on realities outside of ourselves, then how is it that we arrive at these unchanging identities in things when all we know of them are their ever changing perceptions which we sense? Don't our changing senses of them change and alter the idea itself? What then is the source of the "unchanging" nature of it? 12 "... how shall we be able to distinguish the true copy from all the false ones?" 13 

Continuing, he says that if we never get to know the material thing in itself, but only our perceptions and the ideas we have of it in our mind, then the material world is secondary to the ideas in our mind through which we interact with it. We can know our ideas, we cannot know material things-in-themselves. 14 "Properly and immediately nothing can be perceived but ideas. All material things, therefore, are in themselves insensible, and to be perceived only by our ideas." 15 If this is the case, though, why should we posit a material substratum at all? If it is something that I cannot know, and all I can really know are the ideas which belong to my mind and the perceptions generated by the mind, then isn't that the only reality there is? 16 "You are therefore, by your principles, forced to deny the reality of sensible things; since you made it to consist in an absolute existence exterior to the mind." 17


1 - Fieser, James and Emanuel Stumpf. Philosophy: A Historical Survey With Essential Readings. George Berkeley. Three Dialogues Between Hylas and Philonous". Excerpts. Pg 202.

2 - 203

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