Thread: Is Alan Chalmers contradicting himself?

I have the fourth edition of "What Is This Thing Called Science?" and I've noticed something peculiar.

In chapter 5, on page 61, the following two laws are noted:

(a) Mars moves in an ellipse around the sun.
(b) All planets move in ellipses around their sun.

Chalmers writes that (b) tells us more than (a) => (b) is more falsifiable than (a) => (b) is the preferable law.

However, on pages 63/64 I find these two laws:

(1) Planets move in ellipses around the sun.
(2) Planets move in closed loops around the sun.

Chalmers then writes that (1) is more precise than (2) => (1) is more falsifiable than (2) => (1) is the preferable law.

Is Chalmers contradicting himself here or am I missing something?

Other than the use of =>, which is too easy to confuse greater and equal with therefore...

There's no contradiction at all.

If it helps line all three up:

(a) Mars moves in an ellipse around the sun.
(b) All planets move in ellipses around their sun.
(c) Planets move in closed loops around the sun.

Then compare based on the two criteria: falsifiability and precision.
As Chalmer's did, you'll end with different order for each criteria. Quite often the more falsifiable is not the most precise and visa versa.

To expand the discussion as well, often the most precise is the most parsimonious (an ellipse is pretty simple compared to the range of all possible mathematical "loops") used as the platform for furthering deeper hypothesis.

Thanks for your response. The only similarity I see between the two choices is that the one doesn't affect the other.

The falsification of (b) wouldn't affect the falsification of (a), while the reverse would be true.
Likewise, falsifying (1) wouldn't falsify (2), while the reverse would.

When I compare two hypotheses, can I assume that the one that doesnt affect the other, is more falsifiable?

Originally Posted by Deeyennay

Thanks for your response. The only similarity I see between the two choices is that the one doesn't affect the other.

Not sure what you are missing. They are related to one another.

Consider the statements:
1) This apple is sweet.
2) All apples are sweet.
3) All fruits are sweet.

Which are the most useful if you trying to create a "law?"

Which is the most precise?
1) is very precise but too specific to a single example to become a "law"
2) is more precise than 3) because it points to a specific type of fruit.

Which are the easiest to falsify?
Obviously even a single example of a bitter apple would falsify 2), while any bitter fruit (say a cranberry) would falsify 3).

Note you might be able to easily falsify 3) which isnt' very precise but it might be more difficult to falsify the more precise 2)

That is what confuses me. I see how in your last post, 3) is more easily falsified than 2).Chalmers however claims the opposite in the original post ( (1) more falsifiable than (2) ). What is so different about the two comparisons that makes this true?

Originally Posted by Deeyennay

That is what confuses me. I see how in your last post, 3) is more easily falsified than 2).

Because it is general and thus easier to find counter examples....all you need is one to falsify the "law"

Chalmers however claims the opposite in the original post ( (1) more falsifiable than (2) ).

Not really sure which you are referring to.

--

(once you understand the differences, I hope Chalmers takes the time to explain that just about all the "laws" have exceptions and are under idealized assumptions that are good to a first approximation, but break down in nearly every case when compared to precise actual observations.

Originally Posted by Lynx_Fox

Not really sure which you are referring to.

I'll try to clarify some:

---------------------------------------------------------

Originally Posted by Deeyennay

The only similarity I see between the two choices is that the one doesn't affect the other.

The falsification of (b) wouldn't affect the falsification of (a), while the reverse would be true.
Likewise, falsifying (1) wouldn't falsify (2), while the reverse would.

When I compare two hypotheses, can I assume that the one that doesnt affect the other, is more falsifiable?

Here, I am referring to these two:

Originally Posted by Deeyennay

(a) Mars moves in an ellipse around the sun.
(b) All planets move in ellipses around their sun.

Originally Posted by Deeyennay

(1) Planets move in ellipses around the sun.
(2) Planets move in closed loops around the sun.

---------------------------------------------------------

Originally Posted by Deeyennay

That is what confuses me. I see how in your last post, 3) is more easily falsified than 2).Chalmers however claims the opposite in the original post ( (1) more falsifiable than (2) ). What is so different about the two comparisons that makes this true?

Here, the bold references refer to:

Originally Posted by Lynx_Fox

1) This apple is sweet.
2) All apples are sweet.
3) All fruits are sweet.

And the italicised references refer to:

Originally Posted by Deeyennay

(1) Planets move in ellipses around the sun.
(2) Planets move in closed loops around the sun.

Perhaps I should repeat my question now, having offered clearer references.

When I compare two hypotheses, can I (in every case) assume that the one that doesnt affect the other, is more falsifiable?

I think you're confusing the same item with difference hypothetical characteristics, with different object sets. Set objects such as "Mars," aren't appropriate to a law because we can't develop a generalized rule from them. It takes a set (e.g., planets, cats, animals etc) to develop a falsifiable hypothesis.

Originally Posted by Deeyennay

Perhaps I should repeat my question now, having offered clearer references.

When I compare two hypotheses, can I (in every case) assume that the one that doesnt affect the other, is more falsifiable?

Not sure what you mean? If there's only two, than they either effect one another....or they don't.