LOGIC. 
3© 
Expofition and Deficr'iption. 
105. Conceptions do not ail admit of being defined, 
nor is it neceflary that they all fhould. There are, how¬ 
ever, approximations to definitions of certain conceptions, 
which are either Expeditions or Defcriptions. The Expofi¬ 
tion of a Conception confifts in the lucceffive reprefenta- 
tions of its marks fo far as they are difcoverable by Ana¬ 
lyfis. Defcription is the expoiition of a certain concep¬ 
tion fo far as it is precife. 
Remark (1.) We can give an expofition either of a 
Conception, or of Experience it (elf, which is an intuition 
joined to a conception. The former takes place by Ana- 
lyjis, the latter by Synthejis. 
(2.) Expofition takes place only in given Conceptions, 
■which are thereby rendered perfpicuous; this muft be dif- 
tinguifhed from Declaration, which is a perfpicuous repre¬ 
sentation of produced Conceptions. As it is not always 
poffible to render Analyfis complete, an incomplete expo- 
.(ition, as a partial definition, is neverthelefs a true and 
lifeful representation of a Conception. Definition here 
is only the Idea of a logical perfection, which we mult 
always endeavour to attain. 
(3.) Defcription takes place only in empiric ally-given 
Conceptions. It has no determinate rules ; and only 
contains the materials for Definition. 
Nominal and Real Definitions. 
106. By merely nominal definitions are to be under¬ 
stood thofe, which arbitrarily give a meaning to a certain 
name ; and which therefore only denote the logical Cha- 
rafterilkc of their object; or iefve to diltinguilh it from 
other objects. Real definitions are fuch as are fufficient 
to a knowledge of the obje£t from its internal determina¬ 
tions, as they fliow the pofiibility of the object from in¬ 
ternal marks. 
Remark (1.) When a conception is internally fufficient 
to diftinguifh the thing, it is alfo externally fufficient. 
But it may be internally infuffeient, and yet externally 
fufficient. However, abfolute external fufficiency is impol- 
iible without the internal . 
(a.) ObjeCts of Experience admit only of nominal De¬ 
finitions. Logical Nominal Definitions of given Concep¬ 
tions of underltanding, are derived from Attributee. 
Real Definitions are taken from the efence of the thing 
itfelf; that is, from the firfl grounds of pofiibility. The 
latter therefore contain what always applies to the thing, 
that is, to its real elfence. Merely negative Definitions 
cannot be termed. Real Definitions ; for, though negative 
marks ferve to diftinguifh one thing from another, as 
well as affirmative marks ; yet they do not give any in¬ 
formation as to the internal pofiibility of the thing itfelf. 
In moral fubjeCts, we muft always endeavour to obtain 
real definitions. The Mathematics abound in real defi¬ 
nitions ; for the definition of an arbitrary conception is 
always a real one. 
(3.) A Generic definition is that which produces a con¬ 
ception, whofe objeCi: may be reprefented a priori in the 
concrete. All mathematical definitions are of this clafs. 
Chief Reqaiftes of a Definition. 
107. The eflential and univerfal requifites for^erfeCHng 
Definition in general may beconfidered under the four heads 
of Quantity, Quality, Relation, and Modality. 
1. According to E^uantity, namely, what concerns the 
fphere of a definition, the definition and the thing defined 
muft be reciprocal conceptions, and confequently the one 
nek her wider nor narrower than the other. 
2. According to Quality, the definition muft be an am¬ 
ple and yet a precife conception ; that is, it muft be an 
adequate one. 
3. According to Relation, the definition muft not be 
tautological ; that is, the marks of the definition as the 
ground muft be different from the thing defined ; and laftly, 
4. According to Modality, the marks muft be necejfiary ; 
confequently not fuch as are obtained from experience. 
Remark. The condition, that the Generic conception 
and the conception of the Specific difference are to confti- 
tute the definition, takes place only in nominal definition* 
by compavifon, and not in real definitions by derivation. 
Rules for Proving Definitions. 
108. In order to prove definitions four things are to be 
attended to : we have to examine whether the definition, 
1. Confidered as a Propofitiou, be true ; whether it, 
2. Confidered as a Conception, be perfpicuous ; whether it, 
3. Confidered as a perfpicuous Conception, be alio ample ; 
and iaftiy, whether it be, 
4. Confidere'd as an ample Conception, at the fame time 
determined ■, i. e. adequate to the thing itfelf. 
Rules for Forming Definitions. 
109. The very fame things that are required for prov¬ 
ing definitions are to be attended to in forming them. 
With this view we muft fearch for, x, True pofitions; 2, 
Such where the predicate does not already prefuppofe the 
conception of the thing; 3, Collect more of them, and 
compare them with the conception of the thing itfelf, to 
determine whether they be adequate; and, 4, whether 
one mark does not lie in another, or is not fubordinate 
to it. 
Remark (1.) It may indeed eafily be o'oferved, that, 
as thefe rules apply only to Analytical Definitions, and as 
vve never can be certain that the thing has been completely 
analyzed, we muft ftili confider the definition only as an 
attempt, and not ufe it as a definition. Under this limi¬ 
tation we may confider it as a true and perfpicuous 
conception, and draw from it corollaries. For we may 
here obferve, that what applies to the conception of the 
thing defined, applies alfo to the definition; but indeed 
not converfely, fince the definition does not embrace the 
whole of the thing defined. 
(2.) To employ the conception of the thing defined in 
the definition, or to lay the thing defined as a ground for 
the definition, is to define in a circle. 
II. Advancement of the Perfections of Knowledge by the Lo¬ 
gical Divifion of Conceptions. 
Conception of a Logical Divifion. 
1x0. Every conception contains a variety under it; fo 
far they all agree; but in this alfo they differ; for, the de¬ 
termination of a conception in refpebt to all poffible parts 
contained under it, in as much as they are oppofed to one 
another, that is, differ from each other, is termed the logical 
divifion of a conception. The fuperior conception is called 
the divided conception-, and the inferior conceptions, the 
members of divifion. 
Remark. To part a conception is not to divide it. In 
the partition of a conception we perceive what is con¬ 
tained in it (by Analyfis.) In the divifion we confider 
what is claffed under it. Here we divide the fphere of 
a conception, and not the conception itfelf. It is a great 
error to take the divifion for the partition of a conception, 
fince the members of divifion contain much more in them 
than the divided conception. 
(2.) We may proceed from the inferior to the fuperior, 
and afterwards return from the fuperior to the inferior, 
by divifion, 
Univerfal Rules of Logical Divifion. 
in. In each divifion of a Conception, 
1. The members of divifion muft exclude or be oppofed 
to one another; 
2. The}- muft be comprehended under a fuperior con¬ 
ception ; and laftly, 
3. Taken all together, they muft conftitute the fphere 
of a divided conception, or be equal to it. 
Remark. The members of divifion muft be feparated from 
one another by contradictory and not by mere contrary op- 
pofition, 
Co-divifion 
