“At the beginning of this collection is an excerpt from a letter...to Her Highness the Princess of Wales.  Leibniz laments the worsening of the state of natural religion in England, since many imagine the soul corporeal and others claim that even God is corporeal.  He thinks that Locke and his followers at least doubt the soul’s immateriality, and that Newton in the appendix to Optice claims that space is the divine sensorium, which entails that the world is neither dependent on, nor is the production of, God.  Leibniz also reproaches Newton for claiming that things need correction by extraordinary divine concourse in the world’s machine (a view of those who do not discern the human from the divine).
 “Defending Newton’s views, Clarke states that for Newton God does not use space as an organ of perception but perceives everything because of his presence everywhere.  Newton, he continues, considers the brain and the sensory organs the mediums through which the images present to the mind are formed, not the mediums through which the mind perceives them.  Attacking Leibniz’s view, he objects that if the world is taken to be a machine and motion to continue without divine intervention, then one introduces fatality, and that if Leibniz declares God an intelligentia supramundana, he eliminates divine providence and makes the world eternal.
 “In his second letter...Leibniz replies that mere presence is not sufficient for perception, that God perceives things in the world not through mere presence but through operation, and that “sensorium” has always meant ‘the organ of sensation.’  He claims that divine providence is not eliminated but confirmed by the fact that in the world’s machine everything occurs by preestablished design without the need of any correction, since it entails that God has foreseen and predetermined everything.  For if there is a need for correction, then either God must be the soul of the world, or the correction must occur supernaturally, and therefore miraculously.  Moreover, at the beginning of his letter, Leibniz notes that the foundation of Mathematics from which the whole of Arithmetic and Geometry can be demonstrated is the Principle of Contradiction or Identity, namely that the same statement cannot be true and false at the same time.  However, he continues, in Physics and Metaphysics one must add the Principle of Sufficient Reason, which allows to demonstrate almost the whole of Metaphysics and even the principles of Dynamics.
 “In his second reply, Clarke...acknowledges that nothing happens without a sufficient reason why it happens rather than not.  But this reason can be the mere will of God, for example as when one asks why this body has been placed by God in this location rather than another.  He adds that if the divine will could not act but by being predetermined by another cause, it would not be free, and therefore fatality would be introduced.  He denies supposing that mere substantial presence is sufficient for perception; he rather holds that in addition the substance must be alive.  Hence, God perceives things neither by mere presence nor by operation, but by being present to them, and in addition alive and intelligent.  He adds that the word “correction” must be understood not with respect to God but with respect to us, and claims that the word “sensorium” denotes not the organ but the place of sensation.  Finally, he attacks Leibniz’s characterization of what is done by God as miraculous because it eliminates divine rule from the universe.
 “There follows Leibniz’s third letter, which from the beginning shows that Clarke has not understood the Principle of Sufficient Reason.  In fact, a decision without an inclining reason is incompatible with this Principle.  Leibniz points out that the example given by Clarke is based on a chimerical notion of space, which some contemporary English, and most people, consider an absolute entity, while in reality it is but a mere relative entity, namely, the order of coexistences, as time is that of successions.  Without doubt the Principle of Sufficient Reason abundantly shows that space and time cannot be absolute entities.  In fact, since they are uniform, no reason can be given why bodies are placed in this rather than that location, or why the positions are not reversed, or why things have not been created by God a year earlier or later.  But according to Leibniz’s view of space and time, no reason is needed why things are not placed in inverted positions because the two states are indiscernible, and consequently no reason can be given why one should be preferred to the other.
 “Leibniz claims that the fatality Clarke fears is the best order of providence, for brute necessity is avoided when a wise choice occurs.  As for the meaning of the word “sensorium” he refers to Rudolf Glocenius, who in his philosophical dictionary defines “sensorium” as the organ of sensation.  He also denies that the simple presence of an intelligent substance is sufficient for perception, giving the counterexample of a blind or distracted man who does not see.  God is present to things not by situation but by essence, and his presence is shown by immediate operation; by contrast, the presence of the soul is altogether different.  That the natural and the supernatural do not differ with respect to God, a view Clarke takes from Locke and Locke from Spinoza, will not be approved by theologians, continues Leibniz, agreeing with them in considering miraculous what exceeds the natural power of bodies.
 “In his third letter, Clarke replies that even if space were but the order of coexisting things, there would be no reason but the divine will for a body’s placement in this rather than that space, and therefore no argument is here given against the absolute reality of space.  Clarke seems to have convinced himself of the falsity of Leibniz’s view when he says that it entails that the Sun and the Moon would be in the same place they are now even if they were recreated where now the fixed stars are, and that the world moved from its place would still be in it.  He believes to have shown the same about the Leibnizian notion of time when he claims that it entails that God could not have created the world earlier even if one supposes him to have created it some millennia before he actually did.
 “Clarke adds that if there should always be an external reason for the divine will’s determination to action, then God would be determined like a machine.  After close consideration, he admits that God could be called an intelligentia supramundana in the Leibnizian sense.  However, he himself a theologian, does not accept the notion of miracle generally used by theologians (a fact which would be amazing if it did not stem from his prejudice in favor of Locke’s authority), which he deems false because it would seem to entail that animal motions are miraculous.
 “In his fourth letter, Leibniz claims that a mere will without a motive is fictitious and contradictory, as he has amply shown in the Theodicy: choice does not take place among indifferent things because there is no reason why one should be preferred to the other.  Moreover, he claims that indiscernibles are not given, and that the Principle of the Identity of Indiscernibles, which destroys atoms, should be added to that of Sufficient Reason if one wants real notions and demonstrations in metaphysics.  The same principle is used to show that the notion of this universe in another place or time is an impossible fiction.  In addition, he shows that God is not determined by an external cause because he was determined by his understanding before things existed.  He also points out the difference between the cognitions of God and soul, since the former knows things because he produces them, while the latter knows them because God has placed in it a representative principle of what is external to it.
 “Leibniz argues that the notion of miracle as anomalous occurrence is wrong because otherwise strange events would be considered miracles, and he does not see why animal motions should be inexplicable in terms of natural forces.  He adds a postscriptum showing the absurdity of atoms and the void from the notion of divine perfection and the Principle of Sufficient Reason.  Assuming God has given things every perfection which could be given without prejudice to others, Leibniz infers both the plenum and the infinite division of every corpuscle, so that each contains an entire universe of new creatures.  Secondly, he assumes that there is no principle determining a ratio between the plenum and the vacuum.  In fact, as matter is more perfect than the vacuum, there should be a geometrical proportion so that the quantity of matter exceeds that of vacuum as the perfection of the former exceeds that of the latter.  But matter is to the vacuum as something is to nothing.  Hence, there is no vacuum.  Similarly, he argues that there is no reason why the force of nature could be terminated in the progression of subdivision.
 “As Clarke’s fourth answer adds little to the issues and shows he does not understand the force of the Leibnizian principles, intending to see whether his opponent is moved by the love of truth or the desire to contradict, Leibniz explains everything more distinctly and at greater length.  Hence, he shows the difference between physical and moral necessity already clearly explained in the famous Theodicy.  He elegantly demonstrates how neither divine foreknowledge and providence nor moral necessity destroy liberty, and why the motive does not necessitate since the opposite is possible as well.  Leibniz obtains moral necessity from the Principle of Sufficient Reason, but metaphysical necessity from the Principle of Identity or Contradiction, and declares Christian Fate the decree of divine providence, distinguishing it from Mohammedan and Stoic fate.  By “motive” he understands all the dispositions a spirit can have by which it can act freely, namely not only reasons, but also inclinations arising from passions or previous impressions.
 “Leibniz does not admit simple or indiscernible bodies, which he claims result from the wrong positing of atoms and the void, or the lazy philosophy which, not proceeding sufficiently deeply into analysis, believes to have arrived at the first elements.  He claims that indiscernible bodies are not absolutely impossible; however, by the Principle of Sufficient Reason he shows they cannot exist because of the power of the divine wisdom, while mere mathematicians, dealing only with figments of the imagination, can admit a real space beyond the material world.  He locates the cause of resistance not in the quantity of matter, but in the difficulty with which it gives way: for example, floating timber contains less matter than an equal volume of water, and yet it offers more resistance to a ship.
 “Leibniz also shows that the consideration of the situation (and its changes) among things is sufficient to form the notion of space, and that there is no need to assume the reality of anything beyond the things the situation among which is considered. He then obtains the nominal definition of both place and space, and since Clarke could not understand how space could be a quantity if it is nothing but an order of coexistences, he shows how relations can have quantity.
 “We have already indicated how the soul and God perceive things differently; here Leibniz, that very perspicacious man, explains it more clearly, and takes this occasion to show both that preestablished harmony is possible and that it does not impinge on liberty.  He opposes the attractions of Newton and his followers with good arguments and correctly notes that the natural forces of bodies are subject to natural laws, the forces of spirits to moral laws; the former follow the order of efficient, the latter that of final, causation.  Since Clarke claimed that the Principle of Sufficient Reason had been merely assumed and not proved, although he himself (as was above noted) had appeared to admit it before he had understood its force against Newtonian and common views, Leibniz notes that it truth can be seen a posteriori, since one can adduce innumerable examples in its favor and none against it.  It is in the fecundity of truths which are advanced in this letter by Leibniz that we believe the value of the work is found.  Clarke answers Leibniz’s last letter with no less prolixity...but since he persists in defending common hypothesis by now sufficiently known, it is not necessary that we repeat them here.”