First Dialogue: Arguments



Rules of the Game


P= Philonous; H=Hylas


‘Skeptic’ = (A) One who doubts of everything; (B) One who denies the reality and truth or things = (i) One who distrusts the senses; (ii) One who denies the real existence of sensible things; or (iii) One who pretends to know nothing of them.


H and P are most concerned with (ii) and (iii)


Sensible thing = those only which are immediately perceived by the senses (= sensible qualities such as colors, sounds, odors, tastes, feels, etc.).


Immediate perception = without the intervention of others, mediate perception = with the intervention of others.


Material Substance = Senseless being, (extended, solid, moveable, unthinking, inactive, 51), with sensible qualities inhering in it.



Hylas’ Starting Point:


(A) Sensible things are real (The Reality Thesis)

(B) For sensible things to be real is for them to be mind-independent. (The Independence



 Through the arguments of DI, H is led to reject (A). He becomes convinced of

(C) Sensible things are mind-dependent (they are ideas) (The Ideality Thesis)


Because he holds (B), he is led to deny (A). Thus, we moves the man of common-sense, to philosopher (i.e. man who departs from common-sense). The solution, for Berkeley, is to give up (B). The relevant question then becomes to what degree this involves a radical departure from common sense. 


The Pain/Pleasure Argument is suppose to show: (1) Mind-Dependence of Sensible things (pushing against ii above); (2) Refute the existence of Material Substance. H is led to say that sugar is not sweet, etc. because those qualities cannot exist in matter (Error Theory).



The Pleasure/Pain Argument

(1)   A material substance is an unperceiving thing (def’n)

(2)   An unperceiving thing cannot be the subject of pain.

(3)   A material substance cannot be the subject of pain (from 1 and 2)

(4) An intense degree of heat is a pain

(5)   So: A material substance can’t be the subject of an intense degree of heat

(6)   Pain cannot exist without the mind (i.e., unperceived)

(7)   So: An intense degree of heat cannot exist outside the mind (i.e. unperceived)



In order to support Premise (4) of TPA, P uses the following argument:


The Identity Argument


(1)   In placing one’s hand by the fire, one feels a simple, uniform idea.

(2)   The heat is immediately perceived

(3)   The pain is immediately perceived

(4)  So: The intense heat immediately perceived is not distinct from the pain


In order to support (1) of the preceding argument, P uses the following argument


(1) It is impossible to form an idea of sensible pain abstracted from particular sensations of heat, cold, and the like.

(2) A vehement sensation (of heat, cold, etc.) cannot be conceived without pain or


(3) So: Sensible pains are nothing distinct from those sensations in an intense degree


Objection: Why not distinguish between the heat (as it is experienced by us) and the heat as it actually exists in the object (the heat as it really is). While the former might be mind-dependent (and hence unreal), the latter can still be real and exist in the fire?


H draws this type of distinction. And P response to it in various different ways. In order to better understand, we need to consider the context of the new scientific distinction between primary and secondary qualities.



Primary/Secondary Qualities



In the Aristotelian view, the world is how it appears to us. This means that colors and other sensible things (as they appear to us)  really do exist in the world (as accidents inhering substance). The New Science involves a decisive rejection of this claim. In particular, it involves the claim that only primary qualities (such as extension, shape, motion, etc.) exist in the world. Sensations of secondary qualities (such as colors, sounds, odors, etc.) exist only within the mind and are produced by the motions of matter. Thus: The world is NOT how it appears to us. Now there are different ways to make sense of this claim. One way was suggested by Galileo:


Galileo: Colors, sounds, etc. do NOT exist in material objects. We simply have sensations of these things, which are produced in us by motion, etc. In such a view, trees are not really green (and it’s an error the think otherwise). Call this an “error theory”.


Berkeley is hostile to this New Scientific account of the world. He wants to reject the idea that the world is not how it appears to us. In this sense, he is a common-sense realist. His strategy in the First Dialogue is to have Philonous force Hylas into Galileo’s position (i.e. force him into an error theory about sensible things).


The majority of the First Dialogue involves Philonous trying to show Hylas that sensible things ARE mind-dependent (i.e. cannot exist without being perceived by some mind or other). By establishing this, he will force Hylas to deny the reality of sensible things and thereby force him into a kind of skepticism.


Philonous avoids Hylas’ skepticism by refusing to accept the mind-independence condition of real existence. He claims, that despite the fact that sensible things (such as trees, colors, etc.) cannot exist unperceived (by some mind or other) that they are still real and that they continue to exist even when there are no human minds around to perceive them. [i.e. They don’t “poof” out of existence every time I turn my back].


A Closer Look at Philonous’ Arguments(s) for the Mind-Dependence of Sensible Things:


Besides the position of Galileo, we should consider the follow two competing positions:


Malebranche: Secondary-quality terms such as ‘green’, etc. are equivocal. If by ‘green’ one means ‘green as immediately perceived’ then green does NOT exist in the material object. However, if by ‘green’ one simply means the motions in the light which produce the sensation of green, then green does exist in the world. In such a view, whether or not trees are green (etc.) depends on how we are use the term. Call this an “equivocation theory”.


Boyle/Locke: To say that the tree is green is just to say that it has the power or ability to produce the sensation of green in us. In this view, we can look at green in two different ways: (1) as a sensation; (2) as a power to produce the sensation of green. This view has the happy consequence of avoiding both the error and equivocation theories. We can truthfully say that trees are green (and when we do, notably, we are not using ‘green’ in a different sense of the word).



One objection to these arguments involves distinguishing between apparent colors, etc. and actual colors, etc. One can just say this: While apparent color is mind-dependent (and hence not real), actual color is mind-independent (and hence real). Philonous makes two major responses to this. First – he points out that the discussion concerns sensible things (things immediately perceived by the senses). Consequently, any discussion of colors which cannot be perceived  is completely off topic. Second – he makes fun of the idea of real colors that cannot be immediately perceived. Colors that can’t be seen? Sounds that can’t be heard? Odors that can’t be smelled? The problem is that so-called “real” colors aren’t the ones that we perceive. (Here Berkeley is suggesting that the view he is attacking departs from common sense in a crucial way).


Problem: It looks as if Berkeley has a nice response to a Malebranche-style position. According to Malebranche, the motions in the world (which produce our sensations) are NOT immediately perceived (so Philonous’ first response succeeds). Furthermore, it really does seem strange to distinguish between colors (as seen by us) and invisible ones (the real ones).  Yet Berkeley’s response seems to miss out on Locke’s position. 


Locke distinguishes two different ways of looking at sensible things. They can be viewed as sensations. Or they can be viewed as powers to produce sensations.  Locke, however, thought that secondary qualities WERE immediately perceived. Furthermore, he did not think that there were two different senses of “green” (for example). So Berkeley’s response does not seem to apply to Locke.


Solution: For Locke, powers to produce sensations are qualities/modes. As qualities/modes, they are “supported” by a “substratum”. I think that Berkeley responds to Locke by rejecting the very notion of support, thereby preventing Locke from viewing sensible things as “qualities/modes”. They can only be viewed as sensations.