CHAPTER XII.

_CONCERNING THE SELECTIONS AND THE DECISIONS OF ASSEMBLIES._

The probability of the decisions of an assembly depends upon the

plurality of votes, the intelligence and the impartiality of the members

who compose it. So many passions and particular interests so often add

their influence that it is impossible to submit this probability to

calculus. There are, however, some general results dictated by simple

common sense and confirmed by calculus. If, for example, the assembly is

poorly informed about the subject submitted to its decision, if this

subject requires delicate considerations, or if the truth on this point

is contrary to established prejudices, so that it would be a bet of more

than one against one that each voter will err; then the decision of the

majority will be probably wrong, and the fear of it will be the better

based as the assembly is more numerous. It is important then, in public

affairs, that assemblies should have to pass upon subjects within reach

of the greatest number; it is important for them that information be

generally diffused and that good works founded upon reason and

experience should enlighten those who are called to decide the lot of

their fellows or to govern them, and should forewarn them against false

ideas and the prejudices of ignorance. Scholars have had frequent

occasion to remark that first conceptions often deceive and that the

truth is not always probable.

It is difficult to understand and to define the desire of an assembly in

the midst of a variety of opinions of its members. Let us attempt to

give some rules in regard to this matter by considering the two most

ordinary cases: the election among several candidates, and that among

several propositions relative to the same subject.

When an assembly has to choose among several candidates who present

themselves for one or for several places of the same kind, that which

appears simplest is to have each voter write upon a ticket the names of

all the candidates according to the order of merit that he attributes to

them. Supposing that he classifies them in good faith, the inspection of

these tickets will give the results of the elections in such a manner

that the candidates may be compared among themselves; so that new

elections can give nothing more in this regard. It is a question now to

conclude the order of preference which the tickets establish among the

candidates. Let us imagine that one gives to each voter an urn which

contains an infinity of balls by means of which he is able to shade all

the degrees of merit of the candidates; let us conceive again that he

draws from his urn a number of balls proportional to the merit of each

candidate, and let us suppose this number written upon a ticket at the

side of the name of the candidate. It is clear that by making a sum of

all the numbers relative to each candidate upon each ticket, that one of

all the candidates who shall have the largest sum will be the candidate

whom the assembly prefers; and that in general the order of preference

of the candidates will be that of the sums relative to each of them. But

the tickets do not mark at all the number of balls which each voter

gives to the candidates; they indicate solely that the first has more of

them than the second, the second more than the third, and so on. In

supposing then at first upon a given ticket a certain number of balls

all the combinations of the inferior numbers which fulfil the preceding

conditions are equally admissible; and one will have the number of balls

relative to each candidate by making a sum of all the numbers which each

combination gives him and dividing it by the entire number of

combinations. A very simple analysis shows that the numbers which must

be written upon each ticket at the side of the last name, of the one

before the last, etc., are proportional to the terms of the arithmetical

progression 1, 2, 3, etc. Writing then thus upon each ticket the terms

of this progression, and adding the terms relative to each candidate

upon these tickets, the divers sums will indicate by their magnitude the

order of their preference which ought to be established among the

candidates. Such is the mode of election which The Theory of

Probabilities indicates. Without doubt it would be better if each voter

should write upon his ticket the names of the candidates in the order of

merit which he attributes to them. But particular interests and many

strange considerations of merit would affect this order and place

sometimes in the last rank the candidate most formidable to that one

whom one prefers, which gives too great an advantage to the candidates

of mediocre merit. Likewise experience has caused the abandonment of

this mode of election in the societies which had adopted it.

The election by the absolute majority of the suffrages unites to the

certainty of not admitting any one of the candidates whom this majority

rejects, the advantage of expressing most often the desire of the

assembly. It always coincides with the preceding mode when there are

only two candidates. Indeed it exposes an assembly to the inconvenience

of rendering elections interminable. But experience has shown that this

inconvenience is nil, and that the general desire to put an end to

elections soon unites the majority of the suffrages upon one of the

candidates.

The choice among several propositions relative to the same object ought

to be subjected, seemingly, to the same rules as the election among

several candidates. But there exists between the two cases this

difference, namely, that the merit of a candidate does not exclude that

of his competitors; but if it is necessary to choose among propositions

which are contrary, the truth of the one excludes the truth of the

others. Let us see how one ought then to view this question.

Let us give to each voter an urn which contains an infinite number of

balls, and let us suppose that he distributes them upon the divers

propositions according to the respective probabilities which he

attributes to them. It is clear that the total number of balls

expressing certainty, and the voter being by the hypothesis assured that

one of the propositions ought to be true, he will distribute this number

at length upon the propositions. The problem is reduced then to this,

namely, to determine the combinations in which the balls will be

distributed in such a manner that there may be more of them upon the

first proposition of the ticket than upon the second, more upon the

second than upon the third, etc.; to make the sums of all the numbers of

balls relative to each proposition in the divers combinations, and to

divide this sum by the number of combinations; the quotients will be the

numbers of balls that one ought to attribute to the propositions upon a

certain ticket. One finds by analysis that in going from the last

proposition these quotients are among themselves as the following

quantities: first, unity divided by the number of propositions; second,

the preceding quantity, augmented by unity, divided by the number of

propositions less one; third, this second quantity, augmented by unity,

divided by the number of propositions less two, and so on for the

others. One will write then upon each ticket these quantities at the

side of the corresponding propositions, and adding the relative

quantities to each proposition upon the divers tickets the sums will

indicate by their magnitude the order of preference which the assembly

gives to these propositions.

Let us speak a word about the manner of renewing assemblies which should

change in totality in a definite number of years. Ought the renewal to

be made at one time, or is it advantageous to divide it among these

years? According to the last method the assembly would be formed under

the influence of the divers opinions dominant during the time of its

renewal; the opinion which obtained then would be probably the mean of

all these opinions. The assembly would receive thus at the time the same

advantage that is given to it by the extension of the elections of its

members to all parts of the territory which it represents. Now if one

considers what experience has only too clearly taught, namely, that

elections are always directed in the greatest degree by dominant

opinions, one will feel how useful it is to temper these opinions, the

ones by the others, by means of a partial renewal.

A Philosophical Essay on Probabilities · 第 8 / 14 章