From Pavel Tichy, "Constructions,"
Philosophy of Science, 53 (1986), pp. 514-534:
Failure to distinguish clearly between entities and different ways of constructing them is an inexhaustible source of philosophical confusion and doubletalk. The notion of proposition is a case in point. There is an almost universal tendency to impute the structure of propositional constructions to propositions themselves. Although few would maintain that the numbers nine and two and the subtraction function are ingredients of the number denoted by '9 - 2', few will hesitate to regard Tom, Sam, and the taller-than relation as ingredients of the proposition, or state of affairs, denoted by 'Tom is taller than Sam'. Yet the situation is completely parallel. The number seven does not contain the minus function because if it did, it would also have to contain the plus function, since seven is not only nine minus two but also three plus four. Likewise, the fact that Tom is taller than Sam does not contain the taller-than relation, for if it did, it would also have to contain the shorter-than relation, for Tom being taller than Sam and Sam being shorter than Tom are surely and the same fact.
He goes on to say, "A sentence is not a picture of the proposition it denotes but of a particular construction of that proposition."
Tichy's point may be obscured by the tendency of people to play fast and loose with the term 'proposition', using it now to indicate a sentence, now to indicate a state of affairs, now to indicate something not quite either. The way to think of it is this (what follows is partly Tichy, partly me, and so any errors should not necessarily be attributed to Tichy). '9 - 2' is a phrase that tells how to construct a number; another phrase that does this is '3 + 4'. However, while '9 - 2' constructs the same number as '3 + 4', it does not do so in the same way. They differ by construction: 9 - 2 is one way to construct seven; 3 + 4 is a different way to construct seven; 7 is an entirely different way to construct seven (namely, by starting with seven rather than with anything else). 9, 2, and the subtraction operation are elements of the construction of seven; it is absurd, however, to say that they are elements of seven, when they are not even elements of seven as constructed with the elements 3, 4, and the addition operation. If we did say that, of course, we would be committed to saying that every number is is an element of every other number, which is a claim that begins to look, at best, a little murky. The need to insist on this becomes especially clear if we take constructions like 9/0. 9/0 is a construction, and one that arises sometimes in math problems; but there is nothing it constructs, and so there is no number with the elements nine, zero, and the division function as put together in the construction 9/0. '9/0' names a construction that is abortive. It does not name a number, but a construction that fails to construct a number; and likewise, we cannot say that '9 - 2' names a number, but only that it names a construction (one that does succeed in constructing a number). The expressions '9 - 2' and '3 + 4' are said to be equal or equivalent because they name constructions that reach the same number, not because they are names of that number; they are equivalent because they are itineraries with the same destination, not because they are that destination. Think of it in terms of mathematical education. If Joe understands that 12/3 = 4, what he understands is that 12/3 and 4 give you the same number, even though they have different elements. This goes beyond merely having Joe learn the operations involved in the construction (like an imperfect pocket calculator, Tichy says dismissively in another article), to seeing how one constructs numbers using those elements.
Now, consider the sentence 'Tom is taller than Sam'. The sentence has the elements Tom, Sam, and the taller-than relation; but it would be absurd to say that what it names (the 'state of affairs' or 'fact') has these elements, and for exactly the same reason it is absurd to say that the number seven has the elements 9,2, and -. Rather, 'Tom is taller than Sam' is one way of constructing a given state of affairs or fact. You can construct the very same state of affairs or fact in a completely different way, namely, with the elements Sam, Tom, and the shorter-than relation. 'Tom is taller than Sam' is not a state of affairs or fact; it is a way of formulating a state of affairs or a fact; you can formulate that fact in a different way with different elements. The point remains the same whether you talk about facts or properties. 'Tom's being taller than Sam' does not name a different 'property' from 'Sam's being shorter than Tom'; they do not name properties at all. Rather, they name different constructions of the same property. A physicist, a mechanic, and an ordinary Joe might look at the same car and decompose it intellectually in different ways -- into a complex interaction of molecules and forces, or into a combination of functional auto parts, or into this single thing, the car. But it's still the same car. There's nothing controversial about this; the different intellectual constructions of the car by our three different spectators are different ways of constructing one and the same car, or, if you prefer, constructing a formula that yields the car as a terminus for the mind's contemplation. They are different itineraries that culminate in the same destination.
So 'Tom is taller than Sam' does not name the fact that Tom is taller than Sam; it is a way of taking the elements, Tom, taller than, and Sam, and constructing either the true or the false. In other words, the expression 'Tom is taller than Sam' is a way your mind gets either to truth or to something that's not truth. If by 'proposition' you mean what you can think about, come to believe things about, etc. (a destination of thought), then it constructs a proposition (it is an itinerary to get you to that destination). But the sentence is not the proposition it constructs; nor is the sentence a name for that proposition. Rather, the sentence just tells you one way to get that proposition in mind. When I am thinking about 'Tom is taller than Sam' I am taking that construction or path as itself an object of thought, just as I do when I am thinking about '9 - 2 = 7'. Likewise, 'Today is sunny' does not name a state of affairs; it names a construction, a procedure for finding a state of affairs. It is, I would suppose, an incomplete construction, since it constructs different things depending on what today is. But it is quite common to think that we can get away with treating something like 'Today is sunny' as a label for a fact, rather than a way for the discursive intellect to get to a fact.