16 LOG! C. 
heterogeneous. If they are homogeneous, as 5 s the cafe in 
Mathematical knowledge, they mull be numbered. If they 
are heterogeneous, as in Philofophical Knowledge, they 
mull be weighed, that is, eftimated by their effects, or as 
they overcome obltacles in the mind. Thefe obftacies 
have no relation to Certainty, but only fuch a relation as 
one Plaufibility has to another. Hence it follows that 
in the Mathematics only the relation of the infufficient to 
the fufficient grounds can be determined. In Philofophy 
we muft content ourf'elves with Plaufibility, which is a mere 
fubjeftively and practically fufficier.t holding for true. 
For Probability cannot be eftimated in philofophical know¬ 
ledge, on account of the heterogeneity of the grounds. 
But of mathematical Probability we may fay, that it goes 
more than half way towards Certainty. 
Much has been laid on the fubjefl of a Logic of Proba¬ 
bility; but this is impoffible; for, if the degree of the re¬ 
lation of the infufficient to the fufficient grounds cannot 
be mathematically counted, ail rules are ufelefs. Befides 
we can give no other univerfal rules of probability, except 
thefe, that error does not wholly lie on one fide, and that 
there mull; be a ground of agreement in the objeft; alfo, 
that, when error exifts in equal quantity and degree in 
two oppofite arguments, the truth lies between them. 
Doubt is an oppofite ground, or a mere obftacle to 
bolding for true, which may be either objectively or fuh- 
jeClively considered. Doubt is either fubjettively taken as 
the Hate of an irrefolute mind; or objectively, as the 
knowledge of the infufficiency of the grounds of holding 
for true. In the latter fenfe it is an objection-, that is, an 
objective ground for diffielieving a knowledge that is con- 
fidered to be true. 
Scruple is an oppofite ground to the holding for true, 
which is only fubjectively valid. In fcruple we do not 
know whether the obftacle is grounded in the objeft or 
only in the fubjefl, that is, whether it arifes from incli¬ 
nation, habit, &c. We doubt without being able clearly 
to explain ourfelves concerning the ground of doubt. In 
order to remove a fcruple, it muft be raifed to the clear- 
nefs and precifion of an objection. For it is by means of 
objeffions that certainty is rendered clear and perfefl; 
and we cannot be certain of a thing unlefs oppofite grounds 
are ftated by which it may be determined how far we are 
from or how near we are to certainty. It is not fufficient 
that each Doubt fliould have a reply; it muft be refolded, 
that is, rendered conceivable how the fcruple originated. 
If this is not effected, the doubt is only repelled, but not 
removed ; and the feeds of doubt Hill remain. In many 
cafes we cannot indeed determine whether the obftacle to 
holding-for-true has merely fubjeCtive or objective grounds; 
and therefore cannot remove the fcruple by expofing the 
appearance, becaufe we cannot always compare our know¬ 
ledge with the object. It is therefore model!: to propofe 
our objections only as doubts. 
There is a principle of doubt, which confifts in the 
maxim, to confider all knowledge as uncertain, and to 
Ihow the impoffibility of attaining - to certainty. This 
is Scepticifm. It is oppofed to Dogmatifm, which is a blind 
confidence in the power of Reafon, fufferingit, on account 
of its apparent fuccefs, to extend itfelf k priori, without a 
Critic, by means of mere conceptions. Both Scepticifm 
and Dogmatifm, when univerfaliy applied, are erroneous. 
For in great part of our knowledge we cannot proceed dog¬ 
matically ; and Scepticifm,by renouncingall pofitive know¬ 
ledge, puts a flop to all endeavours for the attainment of 
certainty. When, however, Scepticifm is limited to that 
method, which, in the invelligation of Truth, endeavours 
to reduce every thing to the greateft pcffible uncertainty, 
in order that we fliould not a'fi’ume Appearance for Truth ; 
it is then, only a fufpenfion of Judgment, which is highly 
beneficial to Criticifm. The Critical method of Philofo- 
phizing is precifely that which eftabliffies Reafon as its 
leading principle, and rejects all that is unreafonable, 
Thus it extrafts the pure truth which is contained both 
in Scepticifm and Dogmatifm. For this a (Ion idling di f- 
covery we are indebted to the immortal Kant, who has 
founded a Philofophy (fee vol. xi. p. 605.) that muft quiet 
for ever Speculative Reafon, and clear Practical Reafon front 
all charge of contradiction and abfurdity, erecting upon 
this bafis a perfect fyftem of Morals. Criticifm may there¬ 
fore be laid to attain the fumrr.it of all human culture; 
for it conllantly criticifes its own principles, and only 
adopts thofe which are fufeeptibie of apodictical certainty 
and complete demonftration. 
We have already ftated, that Probability is a mere ap¬ 
proximation towards Certainty. This is particularly the 
cafe in Hypothefes, by means of which we can never ar¬ 
rive at apodiCtical certainty, hut only at a greater or lefs 
degree of Probability in our knowledge. An Rypothefis is 
the holding for true of a Judgment, from the Truth of aground,- 
on account of the fufficiency of its confequences’, cr the holding 
for true of a prefuppofition as a ground. 
All holding for true in hypothefes depends upon this, 
that the prefuppofition, as ground, be fufficient to explain 
other knowledge as confequences. For, from the truth 
ot the confequences we infer the.truth of the ground. 
Since, however, this mode of inference affords a fufficient 
criterion of Truth, and can lead to apodiftical certainty 
only when all the poffible confequences of a given ground 
are true; it appears from hence that, as we cannot deter¬ 
mine all poflible confequences, hypothefes will always re¬ 
main hypothefes; that is, prefuppofitions whofe complete 
certainty never can be afeertained. The probability of 
an hypothefis may nevertheleis go on increafing until it 
raifes itfelf to an Analogon of certainty 5 that is, to that 
Hate where all the confequences that have hitherto pre- 
lented themfelves are capable of being explained by 
the prefuppofed ground: for in that cafe there is no rea¬ 
fon why we fliould not fuppofe that all poffible confe¬ 
quences may be explained by it. In this cafe we fubmit 
to the hypothefis as if it were completely certain, although 
it is only fo by induction. 
In every Hypothefis fomething muft however be apo- 
diftically certain, namely ; 
1. The Pofibility of the Prefuppofition itfelf. When, for 
inftance, in order to explain Earthquakes and Volcanoes, 
a fubterraneous fire is luppofied, fuch a fire muft in the 
firft place be poffible, if not as a flaming, yet as a heated, 
fubftance. But, on account of certain other appearances, 
to confider the earth as an animal in which the circulation 
of internal fluids produces this heat, is a mere fancy, and 
no hypothefis. For it is admiffible to fancy a thing real; 
but not to fancy a tiling poflible : this ought to be certain. 
z. The Confequence. This muft flow correctly from the 
aftumed ground, or the hypothefis produces merely a chi¬ 
mera. 
3. The Unity. It is an eflential requifite of an liypc- 
thefis that it be only one, and that it do not require; 
auxiliary hypothefes tor its fupport. If we are obliged, 
for the fake of one hypothefis, to have recourfe to others, 
it thereby lofes much of its probability. For, the more 
confequences are derived from one hypothefis, the mo-re 
probable it is. The hypothefis of Tycho Brahe was fo 
inadequate to the explanation of many of the celeftial 
phenomena, that he had recourfe to feveral new hypothefes 
to fupply its defeats. From this it might eafily have been 
perceived that it was not the true one. This has fince 
been fully evinced. The Ccpernican Syftein is an Hy¬ 
pothefis which explains every thing requifite, as far as our 
experience has hitherto reached. This needs no auxiliary 
hypothefis. 
There are Sciences which do not admit of Hypothefes; 
for example, the Mathematics and Metapbyfics. But in 
Natural Philofophy they are both ufeful and neceffary. 
With refpect to the difference between Theoretical and 
Practical Knowledge, we may remark, that Knowledge 
is termed Practical when it is oppofed, not only to Thee-* 
retkal but to Speculative . 
Prattical 
