106 
PHILOSOPHY. 
thofe who are ignorant of their demonftrations. Of this 
we fee daily inftances in the rules of arithmetic, practical 
geometry, and navigation ; the reafonsof which are often 
not underftood by thofe who pradtife them with fuccefs. 
And this fuccefs in the application produces a convidfion 
of mind, which is a kind of medium between philofophi- 
cal, or fcientifical, and hiftorical knowledge. 
The moft ufual divifion of philofophy, among the an¬ 
cients, was into three parts: dialectics or logic, which 
direCts the operations of the mind, and the formation of 
argument; phyfics, which confiders the ftrudture of the 
world, the effeCts of nature, the exiftence and attributes 
of the Deity, and the nature of the foul; and ethics, 
which lays down moral precepts, and treats of the duties 
of life. 
But by forne it was confined to fome one fcience, or 
branch of fcience: v. gr. to logic, as we find it in Plato 
and Ariftotle: to phyfics, or the knowledge of nature; 
in which fenfe it was chiefly ufed in the Ionic fchool: 
and to ethics, or the rules of morality : thus it is Clemens 
of Alexandria relates that among the Greeks there are 
philofophers who hold difputes about virtue. Agreeably 
to this laft application, Pythagoras defines philofophy a 
meditation on death: by which, according to Plato and 
Clemens, is meant an abftradtion or retirement from the 
body; which Apuleius thus explains: a philofopher is 
to ftudy nothing fo much as to fet his foul at liberty 
from its correfpondence with the body : thus Cicero calls 
philofophy, ars vita , and Seneca, lex vita; and thus Plu¬ 
tarch : “ Conftancy, fidelity, and a found mind, are the 
real philofophy; all the other parts of wifdom, tending 
any other way, are prettinefles and curiofities.” And in 
this fenfe it was that philofophy chiefly flourifhed in the 
fchool of Socrates, afterwards called the Academic School, 
and among the Stoics. 
Philofophy, again, is frequently ufed by Pythagoras 
and Plato for methuphyfics, or the knowledge of God: 
which Plato calls the true philofophy, others the prima 
philofophia; and in refpedt of which, the PJatonifts call 
all other philofophy, nofiurnal, rcxlspi ro (piMaotpici. 
Gale includes the feveral notions hitherto delivered 
under this one general definition : “ Philofophy is the 
knowledge of things natural, moral, fupernatural, and 
notional; originally granted by God to our firfc parents, 
and tranlinitted to us for the honour of the Creator, and 
the good of the univerfe.” 
ThedefinitionofEpidletus isalfo pretty comprehenfive: 
“ philofophy (he fays) confifts in three things; the prac¬ 
tice of precepts, the reafon of precepts, and the proof of 
precepts.” 
Brucker, in his Hiftory of Philofophy, defines philofo¬ 
phy to be “that love of wifdom, which incites to the 
purfuit of important and ufeful fcience.” Philofophy 
difcovers and teaches thofe principles by means of which 
happinefs may be acquired, preferved, and increafed : 
wifdom applies thefe principles to the benefit of indivi¬ 
duals and of fociety. Knowledge which is applicable to 
no ufeful purpofe cannot deferve the name of wifdom: 
Qui ipfi Jihi fupiens prodeffe nequit, nequicquam fapit. 
Some have given the following appellations to the an¬ 
cient philofophy, under its feveral Rages : Philofophy, 
fay they, became impious under Diagoras; vicious under 
Epicurus; hypocritical under Zeno; impudent under 
Diogenes ; covetous under Demochares; voluptuous under 
Metrodorus ; fantujlical under Crates ; fcurrilous under 
Menippus ; licentious under Pyrrho ; and quarrelfome un¬ 
der Cieantbes. 
The feveral dogmata maintained by the feveral philo¬ 
fophers are infinite: Cicero makes no fcruple to aver, that 
“ there is nothing in the world, how abfurd foever, but 
has been maintained by one philofopher or other.” 
From the firft broachers of new opinions, and the firft 
founders of fchools, philofophy has become divided into 
innumerable fedts; fome ancient, others modern: fuch 
are the Platonifts, Peripatetics, Epicureans, Stoics, Pyr- 
rhonians, and Academics; and fuch are the Cartefians, 
Newtonians, Kantefians, &c. 
The moft natural divifion of philofophy is into theore¬ 
tical and pradfical, or phyfical and mental. 
Theoretical or fpeculative philofophy is that employed 
in mere contemplation, and terminating in it. Such is 
phyfics, which is a bare contemplation of nature, and na¬ 
tural things. This, therefore, we call Phyfical Philofo¬ 
phy. 
Practical philofophy is that which lays down the rules 
of a virtuous and happy life ; and excites us to the prac¬ 
tice thereof. Moft authors divide it into two kinds, 
anfwerable to the two forts of human actions to be di- 
redfed thereby ; viz. Logic, which governs the operations 
of the underftanding; and Ethics, properly fo called, 
which diredt thofe of the will. Combined, we call it 
Mental Philofophy. 
I. PHYSICAL PHILOSOPHY. 
Upon this branch of our fubjedf, though extremely 
important, we are able to be very brief, becaufe in two 
preceding articles, Mechanics (vol. xiv.) and Motion 
(vol. xvi.) we have fully explained the Newtonian fyftem 
of phyfics, as now commonly received and underftood ; 
and have alfo given fome extrafls from Sir Richard 
Phillips’s Effays, in contradidfion to the laws of motion 
and of gravitation included in that fyftem. 
Sir Richard has fince more fully developed his fyftem 
of phyfical phenomena, by collecting thofe Eflays from 
thelMonthly Magazine, with additions and explanations, 
into a volume. The beft idea w>e can give .the reader of 
this gentleman’s novel opinions, is by copying his “ Brief 
Synopfis,” which has been printed feparately on a card 
for the inftrudtion of the rifing generation, and, as he fays, 
“ for inviting difcufiion, refutation, or confirmation.” 
It confifts of twenty-five articles. 
1. The Univerfe confifts of extenfion of matter under 
various expanfive, gazeous, fluid, and fixed, forms of body, 
proceeding in relative deniity, from the rareft and moft 
extended fluid media, to the moft condenfed aggregates 
of fixed atoms. 
2. Body is fufceptible of two varieties of motion: i. a 
motion orimpulfe of an aggregate, which occafions it to 
change its place in regard to other aggregates; and, 2. a 
motion of the atoms of an aggregate, created when any 
impulfe from any caufe cannot produce commenfurate 
change of place in the aggregate and diffufe the motion, 
fo that, by re-adtion, the impulfe terminates within the 
body in the mutual adtions of its component atoms. 
3. Motion of both kinds continues to affedl a body, 
until it has been imparted or transferred to aggregates 
in contadf, or has been diffufed or radiated through the 
medium in which it is immerfed ; and this law of the 
equalization of motion, by the contadf of moving aggre¬ 
gates and atoms with others fufceptible of receiving and 
diffusing the motion, is the proximate caufe of all varieties 
of material phenomena. 
4. Motion appears, therefore, to conftitute the life, 
power, and energy, of matter; and is the adlive foul of 
the Univerfe. Matter is its patient, and the relative phe¬ 
nomena of bodies are the reftilts. As it adls on aggre¬ 
gates by contadt, or by impulfe, on and through media, it 
conftitutes the objedt of Phyfical Philofophy; and as it 
affedls compounds or ftrudtures of atoms, it is the objedt 
of Chemical Philofophy. 
5. As no accident of matter can create motion, fo all 
motion may be traced to fome previoufly-exifting motion, 
which has been transferred by mechanical combination ; 
and, as exifting motions are neceflarily transferred and 
diffufed, fo no motion is loft; though, by its equal diffu- 
fion, it may ceafe to exhibit fenfible phenomena. 
6. The facility of receiving motion being equal to the 
facility of diffufing it, and motion in bodies conftituting 
their power, all adtion and re-adtion are neceflarily equal; 
and, motions being inverfely as the number of atoms, all 
bodies 
