Primary and Secondary Qualities

Locke placed the qualities of objects into two categories: primary and secondary. Secondary qualities are things like colour, taste, and the ability to induce pain. They are only the ability of an object to engender a certain perception in us; the perception does not resemble the object. Primary qualities are things like shape, motion, and number. The perceptions within us that these objects engender are actual representations of the objects 'out there in the real world'.

Do you think this is a real distinction?

On some level it is, though I think any mental creation representing the qualities of an object is secondary perception, and primary perception does not attach any sort of qualities beyond the perception itself.

I think "primary" qualities are becoming increasing blurred mostly due to quantum mechanics. Things like the Heisenberg Uncertainty Principle and wave-particle duality could certainly bring number and motion into question. Even shape may be dependent upon our perception if we are viewing higher dimensional objects from a lower dimensional perspective.

I think the interaction of consciousness with reality is crucial and it is possible that there are only what Locke would call secondary qualities.

I guess I would say there isn't a real distinction. I think shape would be perceptually dependent. If you could look at the object closer you would see a bunch of little particles jiggling around not really defining any real shape. Motion is perceptually dependent of course, according to the principle of relativity. Most interestingly though, I think all objects themselves are perceptually dependent on our experience of time unless eternally absolute particles exist.

Clearly it's true that continuity is in a sense a secondary quality; in reality objects are not extended. But I don't think that addresses the issue; we still think that, for instance, our perception of distances between two points (particles for instance) is in some sense a 'true representation' of that which we are experiencing, unlike the subjective quality of colour. Although I would suspect that the distinction is superficial, at any rate it's a strong impression which requires explanation.

I'm also in the "all qualities are secondary" camp. Objectivity is just larger-scale subjectivity, relying upon our shared delusion that we are forms operating in time.

You'll have to explain that further and define the terms you're using, I don't understand what you mean.

I feel that this grouping breaks down at anything more than a superficial glance. I'll use the secondary examples given:

Pain: the type of pain induced, localization, etc. can give you information on an object's state, from it's shape (e.g. a bladed weapon), temperature (cryogenic or thermal burns), and so on.

Colour: most obviously it does tell you something about the object, even if the most you can deduce it that it's covered in a coating that reflects or transmits certain energies of photons. It can indicate temperature (e.g. black body radiation), or a chemical state.

Taste: based on chemical reactions it allows certain deductions about objects to be made.

So, unless I'm misunderstanding what you've written, it would seem rather trivial to disprove. I can't think of any sensation that doesn't correspond to some real world piece of information. After all, that is the entire point of the sensory system...

Yeah, it seems to me like you've misunderstood... the distinction is not about senses actually corresponding to something in the real world, clearly all of them do. The distinction is that, for primary qualities, the correspondence is in some sense a resemblance of the object, whereas for secondary qualities this is not so. An example: taste and isomers. There is nothing actually in food that is 'like' sweetness or bitterness; these subjective sensations inhere only within our brains and not within the substance itself, and are arbitrarily tied to different stimuli so that we may recognise them. There are in fact enantiomers where one of the isomers is sweet and the other bitter; the physical basis is essentially identical, and yet the perceptions are very different. It follows that we can't actually deduce anything about the real substance from the quality of the perception, either. So it's a secondary quality. When we perceive three point particles in space arranged in an equilateral triangle however, we believe that this subjective impression is in fact in some way a true representation of the physical object which is causing it. So it's primary.

It is very interesting, and I only note it now, that we seem to be able to do abstract science precisely with primary qualities but not with secondary ones.

Absolutely. There's no such thing as green outside of human perception. There's electromagnetic waves with a wavelength around 250 nanometers.

Thanks for the clarification.

I'm not entirely sold on the idea because for all we know the internal model that we use to represent shapes, motion, and number could well be arbitrary, and there could be species out there that process the information in such a way that it would be completely alien to us.

Our own models tend to break down at large or small scales, but they work well in the environment we evolved in, and which we normally find ourselves in. It would certainly be possible for models that were 'wrong' to evolve, as long as they were accurate enough that they provided some benefit.

Synesthesia also demonstrates that 'objective' aspects of reality such as numbers and shapes can be tied to arbitrary labels. I wouldn't be surprised if there were animals that counted in what we would call colour, for example.

Quote:

---

Originally Posted by Xei

You'll have to explain that further and define the terms you're using, I don't understand what you mean.

---

Objects have no objective qualities. I had something in particular to explain this with but a spider crawled on my foot and induced a reaction that caused me to lose my focus.

I guess the idea is that "existence comes before essence." Any label or quality you attach to an object is conceptual. It does not accurately represent the object, it only translates or symbolizes the object.

All you are saying is 'there is not a distinction', in oblique ways. I doubt there is an ontological distinction too, but what is required is an argument for your position and an explanation of where the illusion of a problem originates.

Quote:

---

Originally Posted by Xei

we still think that, for instance, our perception of distances between two points (particles for instance) is in some sense a 'true representation' of that which we are experiencing

---

This is an interesting point which I've been thinking a lot about. Considering the continuity of space, distances have been seeming more and more subjective to me, or at least a more mysterious quality than I've thought before. If an infinite amount of points exist in any given amount of space, how would it be possible and what would it even mean for two lines to have the same length, as in an equilateral triangle? Each line would have an infinite amount of points, so how would discrete units of measurement truly describe them, especially considering that those seemingly discrete units would be made of an infinite amount of points? Zooming into the dimensions of the triangle more and more accurately, what's stopping the particles at each point deviating from the equilateral representation with any given unit of measurement considering the continuity of this process? It all seems to really lead to our intuition. What seems to be a more assured quality is something like "the distance between particles x and y is less than the distance between particles x and z" which I wonder is also an arbitrary intuitive quality.