March 28, 2014

## Direct vs. representational perception — the discussion

In prior posts (here and here), I have illustrated representational methods and direct methods.  The illustrations were from science, because that is more public so easier to demonstrate the contrast.  I believe that they illustrate well enough, the distinction between direct and indirect perception.  Both aim to provide the same sort of information about the world.  The method is different, though perhaps the differences are small enough to be confusing.

The primary distinction here is that direct perception is simpler and more direct, and does not rely on computation or inference.  This is why I see direct perception as more likely to be what has evolved, and thus a more likely candidate for explaining human perception.

### Double categorization

One way of seeing the distinction is to look at it in terms of categorization.  Here, I use “categorization” to refer to the dividing up of the world into parts (or categories).  This comes from the old idea (from Plato?) of carving the world at its seams, though the seams might actually be man-made.

March 28, 2014

## Direct measurement of temperature

In an earlier post, I described the representation measurement of temperature.  In this post, I describe the direct method.  The contrast is intended to illustrate the distinction between representational theories of perception and direct theories of perception.  By using an example from science (or perception written big), we illustrate in a way that is easier to see.

### The design of the instrument

The design is almost the same as described in the earlier post.  There is one addition.  The mercury column in the capillary tube is directly calibrated in temperature.  That is to say, there are graduation markings on the thermometer, from which we can directly read off the temperature.

March 27, 2014

## Representational measurement of temperature

As indicated in the previous post, I plan to use the measurement of temperature to illustrate some ideas about perception.  This post will give a representationalist account of measurement, as an illustration of indirect perception.

The apparatus to be used is very similar to a mercury thermometer.  I shall assume that the reader is reasonably familiar with traditional analog thermometers, and how they are used.

### The design of the instrument

The thermometer uses a glass tube.  At the bottom of the tube, there is a largish bulb which can be filled with mercury.  Above the bulb, the glass tube contains only a very narrow tube of small diameter, sometimes called a capillary.

The bulb is initially filled with mercury, and the mercury extends to part way up the capillary tube.  Above the mercury, the tube is empty.  The air is pumped out, though it need not be a perfect vacuum.

March 27, 2014

## Contrasting direct and representationalist (indirect) perception

In a discussion at another site, I am noticing some misunderstanding of what is meant by direct perception.  I’m seeing comments similar to “vision uses photons, so is indirect.”  Those who favor direct perception have never denied that vision uses photons, retinal receptors and neurons.  The usually prefer saying that visual perception is mediated by photons, neurons, etc.  What they disagree with, is the idea that first a representation is formed inside the head, and then we perceive that representation.

Apparently this distinction is confusing.  So I plan a short series of posts where I contrast direct perception and representationalist perception.  This post is the introduction to that series.  The subsequent posts in this series are:

Illustrating with science

It is sometimes said that scientific discovery is learning written big, and scientific data acquisition is perception written big.  The problems that science must solve to acquire useful data are similar to the problems that a perceptual system must solve to gather information about the world.  I shall use that analogy between perception and science, to illustrate what is meant by direct perception.

My next post in this series will give a representationalist account of getting temperature data.  I’ll follow that with a post on a direct way of getting temperature data.  And then, in one more post, I will attempt to point out the important distinctions.

March 23, 2014

## On vjtorley on ways of knowing

Recently, in a post at the Uncommon Descent blog, vjtorley made a post critical of Jason Rosenhouse:

Here, I shall comment on part of vjtorley’s post.

I’m actually a bit puzzled by the whole post.  I read Jason’s blog often enough to doubt that he is claiming that science is the only way of knowing.  I guess I’m also a bit troubled by the expression “ways of knowing” which seems a bit too vague.

Torley begins with:

People who hold the view that “there is a non-scientific source of knowledge about the natural world, such as divine revelation or the historical teachings of a church, that trumps all other claims to knowledge,” are a menace to science. That’s the claim made by mathematician Jason Rosenhouse, in his latest post over at his Evolution Blog.

As I see it, the significant part is “that trumps all other claims to knowledge.”  I don’t see Jason as saying that science is the only way of knowing about the the natural world.  I only see him as denying that what comes from religion can trump science.

March 19, 2014

## An intentionality discussion

A quick note, and a link.

There’s a discussion of intentionality at a site where I participate:

I did not start the topic, but I am one of the participants.

March 15, 2014

## The abortion flap

There has been some recent discussion of abortion, following a statement by Dave Silverman about the secular case against abortion.

My current inclination is to agree with Libby Anne, who points out the secular argument against abortion is just the argument against abortion.  There is nothing especially secular about it.  Perhaps the catholics have a specifically theistic argument, based on declarations from the papacy.  But evangelicals do not.  If anything, their holy book seems to approve abortion in at least some circumstances.

So what am I to make of the post by Massimo Pigliucci:

In that post, Massimo writes:

Of course there are logical, science-based, and rational arguments against abortion.

The argument against abortion is a moral argument.  I’ll grant Massimo that there are rational arguments, because we do reason about moral questions.  But I fail to see that there are logical arguments.  Morality does not emerge from the use of logic.  When we apply logical reasoning, the moral points can be found in the premises, not in the logic.

I really wonder about his comment on a science-based argument against abortion.  Is this the same Massimo as the one who disagreed with Sam Harris’s claim that there is a scientific basis for morality?

### My own position

So what’s my position on abortion?  I personally am opposed, except for special cases such as whether the mother’s health is threatened.  But, frankly, this is a cheap position for me, as a male, to hold.  The decision on abortion should be made by the pregnant woman.  Nobody else is entitled to make her moral judgments.  So call me pro-choice.  The best way to deal with abortion is to avoid unwanted pregnancy.  So call me pro-birth-control.

In summary, I’m not sure what the flap is all about, other than politics.  The abortion issue has received far more discussion than it warrants.

March 9, 2014

## Identity theory skepticism

Identity theory or, in full, mind-brain identity theory, is the philosophical thesis that the mind can be identified with the brain.  This is often stated in the form “mental states are identical to brain states.”

I find the thesis puzzling.  Perhaps that’s partly because it doesn’t make sense to me.  That’s because I have trouble making sense of “mental state” and of “brain state”.  I find it far from clear what either of those means.  So I am puzzled that people want to say that there is an identity between two confusing things.

Presumably, part of the motivation for identity theory, is to have an answer for proponents of dualism.  But we surely don’t need identity theory for that.  It should suffice to claim that activity normally attributed to the mind is the result of what is happening in the brain.

### A music analogy

Here’s a somewhat analogous situation.  We often discuss music in terms of the pitch (or note) being played, or the combination of notes in a chord.  We might perhaps talk of that as the harmonic state of the music.  If the music is being played on a piano, we could also talk of the physical state of the piano.