Greg Detre
Wednesday, 17 January, 2001
Lucy Allais, History of Philosophy I
What is Locke�s distinction between primary and
secondary qualities? Can the distinction be maintained?
Why is the distinction important to Locke�s philosophy?
Are secondary properties real properties of objects?
J. Locke, Essay concerning Human Understanding ([1960], ed. P. Nidditch, OUP, abridgement by J. Yolton, Everyman - II viii, xxi 73, xxiii 7-12, xxx 2, xxxii 14, IV ii 11-12, iii 11-14
Berkeley, Principles part 1 secs 9-15
Mackie, Problems from Locke, ch 1
Dancy, Berkeley, ch 2
C. McGinn, The Subjective View, ch 1, 2, 6, 7, 8
P. Strawson, Perception and its
Objects, in J Dancy (ed) Perceptual Knowledge
G. Evans, Things Without the Mind, in his Collected Papers, especially part III
J. Bennett, Locke, Berkeley, Hume
W. H. Walsh, Reason and experience, OUP
A. J. Kenny, Rationalism, Empiricism, Idealism, OUP
representive??? theory of perception
mentions what Bennett, xxx and xxx have said about it all
attempts to describe what Locke tried/intended/ought to have said in modern language about the whole business of the material world, the primary and secondary qualities of matter, what it is and how matter impinges on our minds
He distinguished the primary qualities of things (e.g., extension, solidity, number) from the secondary qualities (e.g., color, smell, sound), which he held to be produced by the direct impact of the world on the sense organs. The primary qualities affect the sense organs mechanically, providing ideas that faithfully reflect reality; thus science is possible. Later empiricists such as Hume and George Berkeley based their systems largely on Locke's theory of knowledge.
When thinking about these matters, it is important not to confuse two sets of questions:
However, the theory of distinction between primary and secondary qualities is perfectly adequate for the 17th century view of the world, and everyday life today. Even though some of Locke�s ideas had been in error, and some of the examples he gave were not the best examples, I hope I have established that it is possible to detect a tenable difference between primary and secondary qualities in relation to real-life physical objects, the best test being to as yourself, �can I imagine having this idea without an object being there?� If you can find one, or a pair of adjectives which describe the idea without the object, the quality in question is secondary.
�utterly inseparable from the Body, in what estate soever it be; such as in all the alterations and changes it suffers, all the force can be used upon it, it constantly keeps... and the Mind finds inseparable from every particle of Matter� - [1] Locke, J., Nidditch P.H. (ed.), 1975. An Essay concerning Human Understanding, II, viii, �8 (pp.134~135), Oxford University Press, Oxford.
not �, but �
Locke
held that the mind �perceives nothing but its own ideas� (IV.iv.3): the mind
has �no other immediate object but its own ideas, which it alone does or can
contemplate� (IV.i.1).
Secondary
qualities are �nothing in the objects themselvces, but opwer to produce various
sensations in us by their primary qualities, i.e. by the blulk, figure, texture
and motion of their insensible parts� (II. viii. 10.)
Locke was an adherent of psychologism, which in its stronger form believes that advances can be made in epistemology
What�s the difference between �powers�, �grounds� and �bases� in objects?
What are the �powers� in objects � what are the secondary
qualities?
Is it simply that the primary qualities of the object are such that their shape bangs into our eyes (like keys in a lock) in a distinctive way that causes us to see them as colour?
What does Mackie mean
when he talks about misreadings of the �nothing �, but �� sentence? What are
the two alternatives, and which is right?
How does the
experiential content arise in a world composed ultimately of primary qualities?
Do secondary qualities exist in the mind alone, i.e. are they ontologically separate and co-existent with primary qualities, i.e. do they inhere in the objects too, or are they purely properties of our experiental content that arise systematically out of the causal primary properties?
berkeley: took Locke as saying that 2props are in the midn, and argued that primary qualities must be there as well � see the dialogue quoted by Mackie
sarah???: but mackie thinks that the 2props are NOT in the mind
greg???: but are properties that emerge from the primary qualities inherent in the object???
secondary qualities affect other objects of all types, not merely our bodies/perceptual mechanisms/perceptions, e.g. heat from a candle melting wax
draw up my list of primary qualities � continuous position (including size, shape, absolute + relative position) over time, charge � quarks
is there any point to this with quantum theory???
am I an adherent of psychologism??? if I think that the PQ/SQ problem could be solved with the hard problem of consciousness
how much did they know about atoms etc.??? see Britannica. He�s quite prescient about heat and sound as being reducible effectively to molecular kinetic energy patterns in a medium
what�s the difference between powers and the grounds of powers??? example???
does he explain the fact that we make mistakes??? is it relevant to the discussion???
does it work to say (as Mackie does) that primary qualities = the grounds of powers � of what???
grounds of power = PQ on macro scale???
no, it�s more complicated, see Mackie diagram 1
is texture a SQ deriving from minute parts??? yes
where do pain and richness fit in???
are they not SQ that are affecting us (as other objects are affected by SQ) but our bodies not our direct sense/perceptual organs, i.e. by their efffects on our bodies which we register through senses in the stomatch etc. mind you, pain is sort of somatosensory � but not in a tactual(???) sense
�the ideas of PQs resemble the grounds of the powers to produce them while the ideas of SQs do not� � eh???
ah yes � our ideas of PQs, e.g. shape, arise pretty directly out of the objects� actual shape, whereas its colour arises from a systematic relation too, but one whose resulting experiential content (i.e. the idea of the SQ) bears little resemblance to the (power of that???) SQ
what are the major philosophical objections to the PQ/SQ divide and representation???
theory of perception
his argument about PQ vs SQ � those qualities that remain with the body no matter what you do to it, even if you chop it up smaller than we can see � circular, because you only ascribe it microscopic size + shape etc. but not colour due to preconceptions
binding problem
is Locke�s material world a plenum???
don't we need a PQ glue, associating atoms together to form larger objects, which would give rise to solidity, boundaries and texture???
principles of atomic interactivity � emergent properties
can Locke accommodate charge + mass etc.??? do they help???
what�s so wrong with solidity??? how is it different to impenetrability???
can we not replace it with yieldingness/viscosity, though we�re back to glue (see above)
y, but do we have experiences specifically resembling glueyness???
do PQs also have to give rise to experiential correspondent??? why???
apparently so, because the Berkeley/Hume objection seems to require a reformulation
2 qualities of PQ � pg 25+
good explanation � top of pg 28
Descartes � PQs are innate, geometrical, quantifiable, immutable???
isn't the distinction then (pg 28) being made between PQ and SQ that PQs scale up (i.e. our perception of PQ resembles their actual qualities???) whereas not so with SQ???
what is the point of all this in the 20th century???
do we trust microscopes � why are shape + size more fundamental???
more mathematical???
sight + touch = common senses
why is the representative theory untenable???
men who read without being able to see before = answer to Molyneux� problem
Bennett�s distinciton: motion-blindness as a very important maladaptive sensory deficiency
analytic-causal as very important distinction � how???
Platonic veil of appearances; extreme nominalism; innate knowledge
ramifications for the rest of Locke�s philosophy??? innate ideas, ontology/metaphysics, theory of MIND
Locke�s idea of the distinction between PQ and SQ in matter, though he cannot really be credited with its conception(???), remains amongst his most contentious