Sidor som bilder

the primary elements of things, are simple powers, tending to exert a force, or to resist each other in all or in certain particular directions. It is from the co-existence of a multiplicity of the elements, that our Philosopher deduces the phenomenon of extension or space. It is true, says he, that such elements may be supposed to exist severally without space, as they are of no more dimensions than so many mathenatical points; but it is to be remarked, that even a number of mathematical points cannot co-exist without describing some definite yuantity of space; for though they have no dimensions, they have locality; that is, any two of them have each a place diftina from one another, otherwise they would not be two points, but one : thus, though each should take up no space of itself, they must be distinguished or separated by fome space, how small soever; so that an infinite number of them would describe an infinite space, notwithstanding it is universally allowed, that mathematical points are unextended. Again, it is from the peculiar dispositions of these elements towards each other, or from the relations which the different ț ndency of their several directions bear to each other, that he deduces the form of material atoms, the modification of the specific corpuscles of fosile bodies, and the organizacion of the gerinina of plants and animals : the essence of all which he determines to consist in their united design, or in the fyftem or coinbination of the several diftinct wills, or differcnt directions of the finple elements coinposing them; that is, their specific forms.

The effence of the mind, he declares, in like manner, to consist of the organization, or the specific form, of the animal gerin; the intellects of all animals differing from each other according to the organization of their bodies, and their intellects cealing with luch organization. By the mind, however, lays the Author, I do not mean, what Theologues usually understand by the human foul: that a living body dies on the dissolution of its organs, is certain; that animals when dead ccalo to perceive and reflect, is also certain ; that intelleet then, which diitinguished them when living, displays itself no longer; To that the mind, whose existence was inferred from it, must ceale to exist likewise. The liuman soul, as it is conceived by Theologues, is a very different thing, being a simply uncompounded being; or unextended, intuitive, and immortal Spirit ; the existence of which, he says, is not discoverable by Philo ophy, but only froin Revelation. Philosophers, continues he, may make what arbitrary distinctions they please beween foul and body, but they cannot prove the propriety of thein by any physical experiinent whatever. And


lite. cannot, says he, 'that of motion; of changing their ential

hence the exiftence and immortality of the soul would for ever remain a doubt with us, were it not from the assurance we receive, as it is revealed to us immediately from God in the Holy Scripture. Our late philosophical Commentators on the Bible deny, however, in contradiction to this writer, that the iminortality of the soul is a scripture doctrine, making a dirtinction between the doctrine of the soul's surviving the body, and the revival of soul and body at the general Resurrection.

In treating of the energy or action of things, our philosopher observes that much hath been written, and to very little purpose, about the principles of action in matter : but we cannot, says he, separate our idea of the a&tion of phyfical substances from that of motion; bodies, in general, having no other mode of action than that of changing their place. For with regard to the general quality of resistance essential to all substance, he does not consider it as physical action, but as metaphysical energy. Bodies totally divested of motion, or lying perfectly at rest, if any such there be, are totally void of action. As the effence of physical beings confifts also frequently of modes and relations, so is physical action frequently mistaken for substance; several finall bodies in motion being undiftinguishable from a larger body apparently at reft: thus a lever, revolving with great velocity round a center, Thall appear to be a circular superficies. Hence he infers, that the palpable figure and dimensions of all bodies are the effect of the motion of their component parts, and that the form and magnitude of such bodies do not arise from the afsemblage and apposition of the primary eleinents of bodies; which, as before, have neither figure nor dimensions. The forin and extension of bodies, continues our Author, are mere phenomena; to account for which, by imputing form and extension to their primary elements, is to take that for granted which we pretend to demonstrate. The elements being admitted such as above-described, he proceeds to enquire into the reason for their cohesion, in the formation of solid bodies : an enquiry the more curious as the mode of it is totally new; this enquiry, to the best of our reading and remembrance, having never before been attempted on mechanic principles. On this head he takes notice, that it is somewhat surprizing, Physiologists should have so much perplexed themselves to explain the more complicated phenomena of particular bodies, as Magnetilin, Electricity, and the like, without having ex· plained the simple cohesion of the parts, or the tenacity of all bodies in general. The cohesion of the parts of bodies is, according to our Author, the mechanical effect of the resistance given to their motion by the fluid immediately surrounding


thein; which resistance, as it is always proportioned to the velocity of the moving body, may be inexpressibly great, even in a fluid inexpressibly rare or penetrable. Hence be infers, that the intestine motion of hard bodies is quicker than that of soft bodies, and vice versa. The intestine motion of solid bodies, however, he observes, must be harmonical and regular, as in the peculiar modes of this harınony, and regularity of motion, the specific essence of the component corpuscles of different solids confifts. Were any two bodies, says he, in a juxta position constantly to move, or to be moved, together, always in the same direction, and in the same time, we should conceive them, if not otherwise distinguished, to be one body, and not two. It is thus with the parts of bodies : they move Of vibrate one among other in such directions, and in such times, as are compatible with the motion of all; and the reafon they do not separate is, the resistance they meet with from the ainbient Auid. For whenever this fluid is more rare than the internal medium in which they vibrate, the parts are diffipated, and the tenacity or texture of the body is destroyed. On these principles the Author accounts for the fexibility and transparency of bodies; giving a curious inechanical reason why these, with many other qualities of bodies, are incompatible with each other : proceeding with great inethod and regularity to explain the physical cautes of the impenetrability, inactivity, and gravity, of all bodies.

The Laws of motion, as ascertained by Sir Isaac Newton, come next under consideration : our philosopher undertaking to deinonstrate that, according to the principles laid down, they could not possibly be otherwise than they are.—But the short space, to which we must confine our account of foreign books, prevents us fromn dwelling longer on this singularlyingenious tract.

De la Sensibilité, Essai Physique.-A Physical Essay on Sensibi.

Jity. 8vo. Dijon. • At a time, says this writer, when the long-exploded systems of materialisin are again revived; when the spirituality of the human mind and the immortality of the foul are denied by writers of the first name and eminence in the philosophical world; it becomes every friend to religion, morality, and virtue, to exert his talents to oppose that torrent of scepticism and infideJity which threatens to overwhelm us. It is with this laudable view that the present tract is profesiedly written; the author conceiving, if he can make it appear that the most animated inatter is in itself totally destitute of the least fentation, that the



the molt

that the

the nervesc, the animal is of destructie

lary tom of the Moient or ohealth of perimen

notion of matter's being capable of sensibility, perception, and thought, muft, of course, fall to the ground, as without foundation. To this end, he adduces the later experiments and arguments of the anatomists and physiologists respecting the seat or source of sensation. This, he says, they all agree to place in the irritability of the nerves and muscular fibres : but'he observes that, unless in cases of destruction by lightning, virulent poisons, &c. the animal loses its life and sensation long before the nerves and fibres lose their irritability. This is evident froin the contraction of such muscles on being pinched or punctured. He cites a number of experiments also to prove that, even during the life and health of the animal, its sense of feel. ing is totally absent or loft. Hence he infers that, as the. at. tention of the mind, or a consciousness of memory, is necefsary to make even the grosser parts of the body have any feeling, no delicacy of construction can give the more refined parts of such bodily matter any kind of feeling whatever ; much less sensibility, reflection, and sentiment. On this consideration alone he grounds the necessity of animal nature, and particularly the human frame, being formed or actuated by a spiritual thinking substance, essentially distinct and totally different. Reponse aux Queflions proposées aux Métaphysiciens et aux Geom mêtres, c. Par un Docteur de l'Université de Wilna.An Answer to the Questions proposed to the Geometricians and Metaphysicians. By a Doctor of the University of Wilna. To which is added an Essay on the Nature of Motion, by a Doctor of the University of Heidelberg. J2mo. Liege.

The Questions, proposed by the learned Doctor of Wilna, as we understand by a short preface to the present Answers, relate chiefly to the nature of motion : at least to these only hath the present answerer replied.

Queft. 1. Have philosophers hitherto entertained a clear and precise idea of the nature of motion ? And are they well assured that their ignorance, on this head, hath not made thein attribute to motion properties which it has not?

Ansiv. 1. That our ignorance of the nature of motion, or rather our want of a clear and precise method of expressing our ideas of it, hath occasioned many misapplications and wisapprehensions of the Subject.

Quest. 2. Did Diogenes Laërtius reply pertinently to the objections, proposed by Zeno, against the possibility of motion, when he filently „walked about in the midit of an aflembly of Grecian philosophers ? And is it not certain that he imposed on himself and others, in proving something very different from the matter in dispute ?

Anjwv. 2. To answer these questions, it is previously necessary to know what Zeno understood by motion, and whether Díogenes enter. lained the same idea; which does not appear to be the cale. If they

did, they both seem disposed to quibble and to divert themselves, at the expence of others, by playing at cross-purposes.

Queft. 3. If a moving object exists but a single instant in all the places through which it palles, must not another such obje&t, moving twice as fast, exist in the same places only half an initant? And what is half an instant ? Instants or points both of time and space are indivisible.

Answ. 3. This query answers to the ancient quibble of the schools, by which the motion of bodies, or bodies in motion, were denied to have existence. " Bodies,” said the quibblers, « cannot exist where they are not; and bodies passing from one place to another do not exit in either; ergo moving bodies do not exist." Such logic is too impertinent to deterve an answer.

Quest. 4. If, in the defient of falling bodies, their celerity bë constantly increased, they must have an instantaneous velocity (vitelle in. Aantanée] : but there can be no velocity without motion. There must, according to this mode of reasoning, therefore, be an instantaneous motion, which is a contradiction in terms.

Answ. 4. This question is certainly founded on a mere play upon words. If by an instant be meant any portion, however sinall, of time or actual duration, such instant cannot be instantaneous, or deititute of duration. Instants or points of time may, indeed, be compared to points in space, without absolute extension. But there must be a politive distance between any two determinate points, or they would not be divided; they would not be two points, but one. The same may be faid of instants of time; there must be some positive duration between any two, or they would not be distinguishable from each other, and would therefore be but one.

Queft. 5. Desaguliers informs us that one half of the scientific pare of Europe, were fixty years disputing about a mere misconception of terms; a dispute that was reducible to a simple difference only in words, How could and did this happen? Will any one tell me? or is he desirous that I shall tell him?

Answ. 5. If the querist means the dispute about the measure of forces, that dispute is not settled yet; nor is it reducible to a mere dispute about words. If the proposer of the questions, however, will give his answerer his sentiments on the subject, he will think himself obliged by such a reply.

Queft. 6. Ought the profound respect I bear to the genius of the great Newton to prevent my laying that neither he nor any other philofopher hath demonstrated à priori the laws of the composition and rcsolution of motion?

Answ. 6. By no means, if the querist be capable of supplying the deficiencies in the great Newton. On the contrary, his communicating to the world such demonstration à priori, of the laws of the cont. position and resolution of motion, would do him great honour, and give equal satisfaction to the world.

We pass over the other questions, as not immediately relative to the same subject; at the same time our readers will observe, that we have given merely the writer's direct replies, without his illustrations of the principles on which they are founded,


« FöregåendeFortsätt »