Egdeworth on hedonimetry at p. 98 of Peter Newman's edition of
mathematical psychics

Notes on social measurement : historical and critical / Otis Dudley
Duncan, New York : Russell Sage Foundation , c1984


See also Plato's Protagoras (reference found in Otis Dudley
Duncan)copy-paste from Perseus project

356b] That is the only distinction. Like a practised weigher, put pleasant
things and painful in the scales, and with them the nearness and the
remoteness, and tell me which count for more. For if you weigh pleasant
things against pleasant, the greater and the more are always to be
preferred: if painful against painful, then always the fewer and smaller.
If you weigh pleasant against painful, and find that the painful are
outbalanced by the pleasant—whether the near by the remote or the remote
by the near—you must take that course of action to which the pleasant are
attached;
356c] but not that course if the pleasant are outweighed by the painful.
Can the case be otherwise, I should ask, than thus, my friends? I am
certain they could state no alternative.

To this he too assented.

Since that is the case, then, I shall say, please answer me this: Does not
the same size appear larger to your sight when near, and smaller when
distant? They will admit this. And it is the same with thickness and
number? And sounds of equal strength are greater when near, and smaller
when distant?

356d] They would agree to this. Now if our welfare consisted in doing and
choosing things of large dimensions, and avoiding and not doing those of
small, what would be our salvation in life? Would it be the art of
measurement, or the power of appearance? Is it not the latter that leads
us astray, as we saw, and many a time causes us to take things topsy-turvy
and to have to change our minds both in our conduct and in our choice of
great or small? Whereas the art of measurement would have made this
appearance ineffective,

[356e] and by showing us the truth would have brought our soul into the
repose of abiding by the truth, and so would have saved our life. Would
men acknowledge, in view of all this, that the art which saves our life is
measurement [metre^tike^, a term also used by edgeworth NJT], or some
other?
It is measurement, he agreed.

Well now, if the saving of our life depended on the choice of odd or even,
and on knowing when to make a right choice of the greater and when of the
less—taking each by itself or comparing it with the other, and whether
near

[357a] or distant—what would save our life? Would it not be knowledge; a
knowledge of measurement, since the art here is concerned with excess and
defect, and of numeration, as it has to do with odd and even? People would
admit this, would they not?
Protagoras agreed that they would.

Well then, my friends, since we have found that the salvation of our life
depends on making a right choice of pleasure and pain—of the more and the
fewer,
[357b] the greater and the smaller, and the nearer and the remoter—is it
not evident, in the first place, that measurement is a study of their
excess and defect and equality in relation to each other?
This must needs be so.

And being measurement, I presume it must be an art or science?

They will assent to this.

Well, the nature of this art or science we shall consider some other time;
but the mere fact of its being a science will suffice for the proof which
Protagoras and I [357c] are required to give in answer to the question you
have put to us

Nicholas Theocarakis