PHYSICS

th’ejE'having them. This class is not confined to the unorganized

masses of matter; for we see that tne bodies of animals lose alterdeath that organical form, and are assimilated to all the rest of urnthinking beings. From such views as these, while all nationshave agreed to call this class of objects by the name body, whichoriginally expresses our organical frame, some nations, farther ad-vanced in cultivation or relinement, have contrived an abstractterm to express this general substance of which all inanimatebeings are composed. Such terms we have in the words materies,ex>i, matter, See. Matter is that substance which is immediatelyand obviously cognoscible by our senses. Whatever is not thuscognoscible by our senses is immaterial; hence mind is said to-beimmaterial. It is of importance to recollect this di-tinction.Little more is necessary for detecting the sophism of Ilelvctius,M'trabeau, and other sages of the Gallic school, who have endea-voured to remove the ties of moral and religious obligation, bylowering our conceptions of our intellectual nature. It also shewshow hastily they have formed their opinions, who have ascribed tothe immediate agency of mind, all those relations which are ob-served in the actions of bodies on each other at a distance: Thecharacteristic, phamomenon, or distinguishing quality of mind, isintention. The phenomenon by which this quality is suggestedto us is art, or the employment of means to gain ends ; and themark of art is the supposed conduciveness of these ends to thewell-being of the agent. Where this train is not evident, designor intention is never thought Of. We have, and can have, no no-tion of mind different from-those of our own minds; and we dis-cover the existence of other minds as we discover the existence ofbodies, by means of pha-nomena which are characteristics of minds,and which resemble those pha-nomena that follow the exertion ofour own mental faculties, by the employment of means to attainselfish ends; and where such appearances are not observed, no ex-istence of a mind is inferred. When wc see a man fall from thetop of a house, and dasli out his brains-on the pavement, we neverascribe this motion to his mind. Although the fitness of many oftlie celestial motions for most important purposes makes us supposedesign and contrivance somewhere, and therefore a supreme mind,v.-e no more think of inferring a mind in the earth, from the illnessof its motions for purposes most beneficial to its inhabitants, thanof inferring a npnd in a bit of bread from its fitness for nourishingour bodies. The term mind, therefore, in the ordinary languageof all men, is applied to what desires and wills, at the same timethat it perceives and understands. Of all the distinctions whichcan be made among the objects of our contemplation, there isnone of equal philosophical importance with this between mindand matter. The consideration of the latter is the business ofphysics, according to the present import of the term, that whichis material or cognoscible by our senses, occupying the attentionand investigation of the natural philosopher. With regard to theorigin of this science, we may observe that the necessary occupa-tions of ordinary life have oftener directed the efforts of men ofgenius towards material objects, and engaged their attention ontheir properties and relations; and as all sciences have arisen fromarts, and were originally implied in them till separated from themby speculates, the knowledge of the material system of nature waspossessed in detached scraps by the practitioners in the variousarts of life, long before the natural philosopher thought of collect-ing them into a body of science, lint there have been in all agesmen of curiosity, who have been struck by the uniformity of theoperations of nature in the material world, and were eager to dis-cover their causes. Accordingly, while the moralists and meta-physicians spent their time in investigating the pha-nomena ofmind, and have produced the sciences of Pneumatology, Logic ,Lillies, Jurisprudence, and Natural Theology, these observers ofnature found sufficient employment in considering the phenomenaof the material world. The bodies of which it consists are evi-dently connected by those properties by which we observe thatthey produce changes in each other’s situation. This assemblageof objects is therefore justly called the material system. >lt is fre-quently termed nature; and the terms natural appearances, naturalcauses, natural laws, have been generally restricted to those whichtake place in the material system. In order to proceed on sureground in the study ot nature, or of material substances, philoso-phers have laid down certain axioms and given ruh.fi for philoso-phizing, .which we shall proceed to notice.

VOL. IV.—NO. 17t).

SOI

I Axioms relating to Physics; of the Rules of Philoso-phizing, AND OF THE VARIOUS PROPERTIES OF MATTER.

: The fundamental principles, or axioms, on which this sciencedepends are the following :

• Axiom 1 . Nothing has no properties.

Axiom 2. Somewhat does exist.

Axiom 3-. There is no medium between something and nothing,existence and non-existence.

Axiom 4. That which exists, and is independent on any othercreated being for its existence, is properly the essence or sub-stance of the thing existing.

Axiom 5. No substance, or essence, can produce itself; or it isimpossible nothing should become something.

Axiom G. No matter, substance, or essence of anything, is ca-pable of being reduced to mere nothing, or annihilated.

Axiom 7. Every effect has some cause, pre-existent to itself.Axiom S. If we ourselves are not the cause of any effect,then that effect must depend on, and result from, some other-cause.

Axiom 9. All things, as far as in them is, continue in the same-state in which they began their being.

Axiom 10. Every change is produced front some externali cause.

Axiom 11. Every change made in any body, is always propor-tionable to the powers of the cause producing it. Thus, the mo-tion of a body is always in proportion to the greatness of the power,or stroke, that put it "first into motion.

The most unexceptionable rules of philosophizing are the fol-lowing, as laid down by Sir Isaac Newton:

Rule 1. We must take care to admit no more causes of naturalthings than what are true, and sufficient to explain their pheno-mena.

Rule 2. We must observe always to assign the same causes forthe same natural effects.

Rule 3. Those qualities which cannot be increased, or dimi-nished, and agree to all bodies in which experiments can bemade, must be adjudged the properties of all bodies in ge-neral.

Rule 4. Propositions and conclusions, deduced from actual ex-periments, must be esteemed true and accurate, notwithstandingany hypotheses, or received suppositions, to the contrary ; andmust be insisted on till some other phenomena, either render themmore accurate, or liable to exception.

Philosophers of the present age almost entirely reject hypo-theses in physics, thinking that which depends on bare hypothesisand conjecture, unworthy the name of philosophy ; and thereforehave framed new and more effectual methods for philosophicalenquiries. However, to discard all hypotheses from physics, is toreduce it within very narrow limits ; and indeed hypotheses duly-qualified, if not absolutely necessary, yet may be very subservientto natural philosophy ; but the hypotheses may be productive ofharm instead of advantage to physics if they have not most or allof the following qualifications: I. They must be agreeable to justreasoning. 2. They must be necessary for want of experience.3. They must be consentaneous to experience. 4. They must besufficient to satisfy the phenomena. 5. They must be naturally-adapted to the case. 6. They must be possible on every ac-count. 7. They must be probable in their own nature. 8. Theymust be tree from all suspicion of prejudice, affection, or prepos-session, in their author.

The properties of bodies come next to the examined, and theseare divided into such as are common to all bodies alike, and thosewhich are peculiar to each in particular: the first are called com-mon and essential, the latter specific and accidental. The lb ftsort are generally reckoned these which follow: 1. Inertia, for allbodies are inert." 2. Extension, for all bodies are extended. 3.Divisibility, for all boclies may be divided 4. Solidity, for theparticles of all bodies are hard. 5. Figurabiljlv, for all bodieshave some form or figure. 6. Mobility, for all bodies are capableof being moved.

The other properties of bodies, called specific or accidental, aregenerally reckoned the following: 1. Light. 2. Colours. 3.Sound. 4. Gravity and Levity. 5. Attraction andElectricity. 6. Transparency and Opacity. 7. Den-4 II sity