6,064
edits
No edit summary |
No edit summary |
||
Line 57: | Line 57: | ||
N.B. "x" can't be the name of this actual scratch y, because this isn't a thing: but it can be the name of ''a thing;'' and we must understand that what we are doing is to explain what would be meant by saying of an ideal symbol, which did actually consist in one ''thing's'' being to the left of another, that in it a ''thing'' symbolized. | N.B. "x" can't be the name of this actual scratch y, because this isn't a thing: but it can be the name of ''a thing;'' and we must understand that what we are doing is to explain what would be meant by saying of an ideal symbol, which did actually consist in one ''thing's'' being to the left of another, that in it a ''thing'' symbolized. | ||
(N.B. In [the] expression (∃y). φ''y,'' one ''is'' apt to say this means "There is a ''thing'' such that...". But in fact we should say "There is a y, such that..."; the fact that the y symbolizes expressing what we mean.) | |||
In general: When such propositions are analysed, while the words "thing", "fact", etc. will disappear, there will appear instead of them a new symbol, of the same form as the one of which we are speaking; and hence it will be at once obvious that we ''cannot'' get the one kind of proposition from the other by substitution. | |||
In our language names are ''not things'': we don't know what they are: all we know is that they are of a different type from relations, etc. etc. The type of a symbol of a relation is partly fixed by [the] type of [a] symbol of [a] thing, since a symbol of [the] latter type must occur in it. | |||
N.B. In any ordinary proposition, e.g., "Moore good", this ''shews'' and does not say that "''Moore''" is to the left of "good"; and ''here what'' is shewn can be ''said'' by another proposition. But this only applies to that ''part'' of what is shewn which is arbitrary. The ''logical'' properties which it shews are not arbitrary, and that it has these cannot be said in any proposition. | |||
When we say of a proposition of [the] form "aRb" that what symbolizes is that "R" is between "a" and "b", it must be remembered that in fact the proposition is capable of further analysis because a, R, and b are not ''simples.'' But what seems certain is that when we have analysed it we shall in the end come to propositions of the same form in respect of the fact that they do consist in one thing being between two others. | |||
How can we talk of the general form of a proposition, without knowing any unanalysable propositions in which particular names and relations occur? What justifies us in doing this is that though we don't know any unanalysable propositions of this kind, yet we can understand what is meant by a proposition of the form (∃x, y, R) . xRy (which is unanalysable), even though we know no proposition of the form xRy. | |||
If you had any unanalysable proposition in which particular names and relations occurred (and ''unanalysable'' proposition = one in which only fundamental symbols = ones not capable of ''definition'', occur) then you can always form from it a proposition of the form (∃x, y, R). xRy, which though it contains no particular names and relations, is unanalysable. | |||
(2) The point can here be brought out as follows. Take φa and φA: |