Exercise your brain!

Several Thought Experiments



William James’ squirrel:


SOME YEARS AGO, being with a camping party in the mountains, I returned from a solitary ramble to find every one engaged in a ferocious metaphysical dispute. The corpus of the dispute was a squirrel – a live squirrel supposed to be clinging to one side of a tree-trunk; while over against the tree’s opposite side a human being was imagined to stand. This human witness tries to get sight of the squirrel by moving rapidly round the tree, but no matter how fast he goes, the squirrel moves as fast in the opposite direction, and always keeps the tree between himself and the man, so that never a glimpse of him is caught. The resultant metaphysical problem now is this: Does the man go round the squirrel or not? He goes round the tree, sure enough, and the squirrel is on the tree; but does he go round the squirrel? [Stop for discussion] In the unlimited leisure of the wilderness, discussion had been worn threadbare. Every one had taken sides, and was obstinate; and the numbers on both sides were even. Each side, when I appeared therefore appealed to me to make it a majority. Mindful of the scholastic adage that whenever you meet a contradiction you must make a distinction, I immediately sought and found one, as follows: “Which party is right,” I said, “depends on what you practically mean by ‘going round’ the squirrel. If you mean passing from the north of him to the east, then to the south, then to the west, and then to the north of him again, obviously the man does go round him, for he occupies these successive positions. But if on the contrary you mean being first in front of him, then on the right of him, then behind him, then on his left, and finally in front again, it is quite as obvious that the man fails to go round him, for by the compensating movements the squirrel makes, he keeps his belly turned towards the man all the time, and his back turned away. Make the distinction, and there is no occasion for any farther dispute. You are both right and both wrong according as you conceive the verb ‘to go round’ in one practical fashion or the other.”

“What is pragmatism?” 1904 lecture [1]

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S’s Sermon: NOT by chalk and talk

Stained glass at St John the Baptist's Anglica...
Stained glass at St John the Baptist’s Anglican Church http://www.stjohnsashfield.org.au, Ashfield, New South Wales. Illustrates Jesus’ description of himself “I am the Good Shepherd” (from the Gospel of John, chapter 10, verse 11). This version of the image shows the detail of his face. The memorial window is also captioned: “To the Glory of God and in Loving Memory of William Wright. Died 6th November, 1932. Aged 70 Yrs.” (Photo credit: Wikipedia)

The Philosophical Society of England has advocated both the use of philosophical material, and perhaps more importantly, philosophical methods in schools, a prominent strand in its history since the 1930s. We reprint from the archives Bernard Youngman’s 1952 assessment of the task of a philosophical education, a task he bases on Bible study and describes as part of leading the young untutored mind towards love of wisdom and knowledge. The teacher, he warns, “must value freedom of thought and revere independence of mind; he must at all times be as Plato so succinctly put it – midwife to his pupils’ thoughts.”

How Mr Youngman combined this duty with his other one, also hinted at, of bringing the young to the realisation that Christianity is the ‘highest’ form of philosophy is part of the challenge. And there are other responsibilities too, of course. 

In Ecclesiastes  there is bitterness and cynicism enough to challenge any adolescent; there is clearly an attitude of sheer materialism, and the writer is devastatingly frank in his statements God, he says, is far away, and not interested in the world or the people in it; He allows evil to flourish all is vanity! Man is just the victim of chance and time. But, he adds, have a good time while the going is good. Here is an almost modern pessimism, and a small dose of this philosophy is probably quite sufficient for the average adolescent.  (Most ‘Agreed Syllabuses’ recommend chapters xi and xii as being enough.)

But the great thing to remember, he concludes, “is that the work must be theirs – by search, preparation, explanation, drama, brains trust, question and answer, project, exploration, study – NOT the teacher’s, by chalk and talk!”  – Source


God = Nature

The claim that God = Nature is interesting.

But it looks a lot like this claim: the morning star is the evening star. And the truth of that claim is a matter of science (observation). What observations support the God = nature claim? Or, is it simply a renaming?

The Morning Star and The Evening Star

The ancient Greeks, looking at the dark sky above them, noticed two very bright stars. One came up shortly after the sun went down in the evening, and was brighter than any other star around it; the other star came up shortly before the sun came up in the morning and was similarly bright. They named these two stars: “The Morning Star” and “The Evening Star”.

It turns out that these two stars were actually the same object: Venus. (Of course, not even a star after all, but a brightly reflective planet.) So here’s the referential picture the ancient Greeks had:

Morning Star / Evening Star Greeks

A few centuries later, astronomers gave us this picture instead:

Reference Venus

Now, if reference is all there is to meaning, then these two sentences would have the same meaning:

“The Morning Star is the Morning Star.”

“The Morning Star is the Evening Star.”

Because by just considering reference those two sentences translate to this one sentence:

“Venus is Venus.”

Reference Sentences

But clearly these sentences have very different meanings — the first sentence is obvious to anyone, even those without any knowledge of astronomy; the second sentence is something that one would only know by virtue of synthesizing some significant piece of astronomical knowledge, namely that “The Morning Star” and “The Evening Star” both refer to the same heavenly body: Venus.

Frege’s Solution

So hopefully you’ll agree that reference can’t be all there is to meaning.

Frege’s idea was that while reference is important to meaning, there is another important dimension to meaning as well, which he called sense. He called the sense of a term the “mode of presentation” of the referent. So while “the Morning Star” and “the Evening Star” both refer to the same thing, they have different senses: the sense of “the Morning Star” is something like “the bright star that rises in the early morning”, while the sense of “the Evening Star” is something like “the bright star that rises in the early evening”. Same reference; different sense.

On this scheme, when we say “the Morning Star is the Evening Star”, we’re comparing senses, not references, and this is why it’s a statement of new knowledge (synthetic, a la Kant) and not just an obvious truth (analytic, a la Kant). “The Morning Star is the Morning Star” is comparing two things that not only have the same references, but the same senses. And this is semantically not interesting.