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Logic, or Rational Thoughts on the Powers of the Human Understanding; With Their Use and Application in the Knowledge and Search of Truth. Translated ... to Which Is Prefixed a Life of the Author.
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This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.
As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
- GenresPhilosophy
336 pages, Paperback
First published January 1, 1983
23 people want to read
About the author
Christian Wolff
632 books20 followersChristian Wolff was a German philosopher. The mountain Mons Wolff on the Moon is named in his honor. Wolff was the most eminent German philosopher between Leibniz and Kant.
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July 11, 2024
THE GERMAN ENLIGHTENMENT PHILOSOPHER WHO PRECEDED KANT
Christian Wolff (aka ‘Baron Wolfius’; 1679-1754) was a German Enlightenment philosopher. He wrote in the Preface to the First Edition (1712) of this book, “there is no other possible means to arrive at this knowledge, than by learning to form just conceptions of solidly demonstrated truths, and then examining how they might have been found, and when by this means we attain to some practice in reflection, to endeavor to investigate unknown truths ourselves; and lastly, to make it our business to enquire into the reason, why we gain so distinct a conviction from demonstrated truths, and how it comes, that from a few known truths, we can draw others, till then unknown.” (Pg. liv-lv)
In his “Short View of the Following Logical Treatise,” he outlines, “we have a twofold judgment, one, taken immediately from the representations of the objects; the other drawn from ratiocination: the former, I call intuitive judgments; the latter, discursive. To all this knowledge … we require three operations. We either barely represent an object to ourselves, without proceeding any further; of we form a judgment thereon, either from the notions themselves, or by means of syllogism. And thus the whole is reducible to these three operations; viz, of representing an object, judging of it, and reasoning about it… as we cannot possibly judge of an object, without a representation thereof, unless we would by rote repeat the judgment of another person, it is absolutely necessary to treat first of simple representation or apprehension, or of the doctrine of ideas or notions.” (Pg. lxvii-lxviii)
He explains, “this I mention here, that others also may examine my logic by the same test, or be enabled to see, whether the logics recommended by others, will stand the trial or not. I myself have experienced the power of prejudice with respect to logic, in the case of aiming at certainty, and seeing things with our own eyes. And in the first place, I have analyzed mathematical demonstrations, and found, I never had any instance, the ground or reason of which I could not assign from my logic. And hereby I discovered, that my logical rules are, that which a regular and complete demonstration is in mathematics, particularly in geometry; and thus I have been convinced, that they are a just sample of the mathematical method.” (Pg. lxxxi-lxxxii)
In His Preliminary Discourse, he states, “Among possible things, we must admit of one necessary, self-existent Being, otherwise something would be possible, of which no sufficient reason could be assigned, contrary to what was established above… This self-existent Being we call God. Other things, which have the reason of their existence in the self-existent Being, we call Creatures. Now, as the business of philosophy is to assign the reason of the possibility of all things, the doctrine concerning God claims preferably an inquiry, previous to that of the Creatures; an accurate knowledge of which last is to be reduced into, or rather deduced from, their first principles. Though indeed we readily admit we must have a previous common or vulgar knowledge of them, but which we have no occasion to draw from philosophy, as from our early years we have it from experience. That branch, therefore, of philosophy, which treats concerning God, and the origin of the Creature, is called Natural Theology.” (XI, pg. 5-6)
He says, “We either proceed no farther in our knowledge than the powers, which produce effects in nature, or we advance one step farther still, namely, in accurately measuring the quantity, both of the powers, and of the effects, in order to shew, that certain powers may produce certain effects. For instance, either we rest satisfied with knowing, that the air, violently compressed, can force water to a considerable height in a fountain, or we attempt accurately to discover the degree of force imparted to the air, when compressed to the half, the third, the fourth, etc., of its former space, and how many feet high it forces the water in each case. This last degree of knowledge requires the measuring of things, that have quantity. With this view Mathematics were invented… And thus mathematics lead us to the most accurate and perfect knowledge possible to be attained.” (XV, XVI, pg. 7-8)
He asserts, “As everything, if we except the self-existent Being, has a sufficient reason why it is, rather than is not; or at least why it can be, or be possible; so things may admit of a real, which admit not of a nominal definition: As for instance, no properties, or no marks intrinsical determinations can be assigned, by which to distinguish Pleasure from all other alterations happening in the mind; yet, notwithstanding it may be shewn, how it arises; namely, when we are sensible of a degree of Perfection in ourselves, or, at least, imagine, we are sensible of it.” (Ch. I, XLVII, pg. 45-46)
He explains, “By these Syllogisms we investigate what is discoverable by human understanding, and demonstrate to others whatever they want to be convinced of, in order to a manifestation of its truth, though we have not always distinctly before our eyes, either in investigating, or in demonstrating, the Syllogistic form or method. But whoever duly attends to himself, when mediating or demonstrating, will be abundantly convinced thereof. My writings, both mathematical and philosophical… paved the way to a solid knowledge of Nature and Art, are a sufficient proof of this… Let no one imagine, that a proof can be completed in a single Syllogism. For as we admit the Conclusion, only on account of the Premises, we cannot be assured of its Truth, till we are convinced of the Justness of the Premises. And therefore the Premises are so long to be proved by other Syllogisms, till we come to such a Syllogism, as has for its Premises either Definitions, Axioms, clear Principles taken from experience, or Propositions previously demonstrated.” (Ch. VI, XX-XXI, pg. 90-91)
He acknowledges, “Now I foresee it will be alleged by the Sneerers at Syllogisms, that it is impossible to discover any thing by their means, as the Conclusion, which I am to find, must be known, before ever I can form the Syllogism. That which therefore is to be found, must be known, before it can be found, which is manifestly absurd. But does not the formation of Syllogisms… plainly shew, that we first know the Premises, and that they may come together into our minds, before ever we have thought of the Conclusion?... the whole of the Algebraic Calculus, by means of which so many discoveries are at this day made in the Mathematics and their kindred Sciences, is performed by pure, Formal Syllogisms; but only shew the manner, in which the above geometrical Theorem was discovered by means of such Syllogisms.” (Ch. VI, XXIV, pg. 97-98)
He observes that “things are very often other than, or different from, what they appear to us. And therefore we must be on our guard, not to judge directly, that things are really such, as they happen to strike our Senses: For thence have arisen numerous prejudices and errors, which have checked the progress of the Sciences, and have been so much the more zealously maintained by the Learned, as they imagined, they had Experience in their favor. Thus most people imagine, that the Earth is the Center of the World, and the only habitation for rational creatures; that the Heavens are the Canopy over our heads; and that the Sun and Stars move round us in twenty-four hours; as all this appears to our Eyes. And therefore it is of great service, to learn by what laws the Representations of things are formed in our Senses…” (Ch. V, XIV, pg. 120)
He argues, “we assume in the doctrine of Morality, that a Trust in God ought to be raised in the mind of a certain person. Now if I enquire, what is Trust in God, I find, that it arises from a certain persuasion, that God both knows in what manner to help, and that he can and will help. And therefore I recollect all that I know concerning God, and among other things I find, that he is all-knowing and all-wise, all-powerful and all-good. And here it occurs, that he who is all-wise and all-knowing, knows how to help; he who is all-powerful, can help; and he who is all-good, will help. And thus I thence conclude God knows how to help, and can and will help. From this I plainly see, that in order to bring a person to trust in God, we must give him a distinct notion of God’s omniscience, wisdom, power and goodness, and bring him to a conviction of these divine attributes. In the doctrine of Morality and Politics we shall have the Solution of many Problems in this manner.” (Ch. VI, VI, pg. 128-129)
He notes, “And therefore, as the Mathematics are the only Science almost in which hitherto strict Demonstrations have obtained; so the surest means to arrive at Science, is the serious and indefatigable Application to them at first, and then, as much as may be, introducing to the other Sciences the Mathematical Method: I say on purpose, as much as may be; for this Method does not succeed in all cases; and where it does, it carries us to excessive Prolixness, if we would keep up in all things to the rigor of it.” (Ch. VII, II, pg. 140-141)
He acknowledges, “But what is an Opinion to some, is not so to all; for One may be certain of what appears to Another but probable. And thus he has either the Science, or demonstrative Knowledge thereof, or he plainly sees it is an Error. So persons of Penetration are aware, that the common Opinion concerning the Essence of body is an Error, for they find, that the power of Resistance is common to all bodies, which on no account depends on Extension. Again it is possible, that some may deem bare Opinions to be undoubted Truths; namely, if they neither understand the nature of a just Demonstration, nor are duly exercised in the practice of Meditation and reflection, nor employ a sufficient time in Discussion… Now as we have no demonstration of Opinions, but assume in the proof some Propositions, which cannot be fully proved, there always remains a fear or suspicion, that the contrary may be true. And thus Opinions yield the mind no complete satisfaction, especially that of an intelligent Person, and one ardently desires after Truth.” (Ch. VI, XX-XXII, pg. 147-148)
He asserts, “If we cannot perceive from a Book, whether the Author extends his Propositions beyond the due limits of Experience, or adduces Propositions with Proof, which otherwise ought not to be admitted, or presupposes such Propositions in his Proof, as are less known, or at least less familiar to the Reader; such a book is INACCURATE. On the contrary, if every particular is sufficiently explained and proved, the book is ACCURATE.” (Ch. X, XVI, pg. 179-180) He adds, “In fine, if the following Propositions are connectedly drawn from the foregoing, as is usually done in Mathematics, every thing hangs well together. And the contrary, if not.” (XXI, pg. 181)
He contends, “Now as to the Holy Scriptures in particular, the Spirit of God does not usually excite the Notions in our Minds immediately, which we are to join with his Words” As in that Case there would be no necessity of translating the Original Text into other Languages, as it would suffice to read with an earnest desire of understanding the Scriptures, and of applying them to our own State, for the Holy Spirit to produce in us these Notions. But this is contradicted by Experience… And thus, God as well in his Word, as any other intelligent Writer, must either explain, what Thought or Notion we are to join with this or the other Word, or he must presuppose no other Notion, but what we have had before.” (Ch. XII, II-IV, pg. 188-189)
He states, “Now as in other particular dispositions, by what names soever called, one Man excels another, just so in the Powers of Understanding, one Man is more qualified for the Operations therefore than another. If therefore two Persons, with different natural Abilities, apply to the study of Logic, and give equal diligence to acquire a Habit of the practice of it, yet one shall far outstrip the other… If then we would distinctly determine the preeminence of natural Logic to Artificial, we must say, a Person naturally more qualified for the Operations of the Understanding than another, yet both employing and equal degree of application in the study and practice of Logic, the former will far excel the latter. Whence it follows no in the least, that we must prefer the natural to the artificial Logic; as this last explains, in a distinct manner, the Rules of the Natural, and besides, enables us to raise our natural Aptitude to a Habit.” (Ch. XVI, III, pg. 215-216)
In philosophy, Wolff is much overshadowed by Leibniz and Kant (he dates chronologically in-between them). And it is much harder to obtain translations of his works. (And this particular edition---a photostatic reprint, where an older book was obviously just placed on the photocopy machine, even if the “margins” are sometimes unreadable---is pretty bad, I must admit.) Still, he was a historically important figure in the German Enlightenment, and serious students of the history of philosophy may find his works interesting.
Christian Wolff (aka ‘Baron Wolfius’; 1679-1754) was a German Enlightenment philosopher. He wrote in the Preface to the First Edition (1712) of this book, “there is no other possible means to arrive at this knowledge, than by learning to form just conceptions of solidly demonstrated truths, and then examining how they might have been found, and when by this means we attain to some practice in reflection, to endeavor to investigate unknown truths ourselves; and lastly, to make it our business to enquire into the reason, why we gain so distinct a conviction from demonstrated truths, and how it comes, that from a few known truths, we can draw others, till then unknown.” (Pg. liv-lv)
In his “Short View of the Following Logical Treatise,” he outlines, “we have a twofold judgment, one, taken immediately from the representations of the objects; the other drawn from ratiocination: the former, I call intuitive judgments; the latter, discursive. To all this knowledge … we require three operations. We either barely represent an object to ourselves, without proceeding any further; of we form a judgment thereon, either from the notions themselves, or by means of syllogism. And thus the whole is reducible to these three operations; viz, of representing an object, judging of it, and reasoning about it… as we cannot possibly judge of an object, without a representation thereof, unless we would by rote repeat the judgment of another person, it is absolutely necessary to treat first of simple representation or apprehension, or of the doctrine of ideas or notions.” (Pg. lxvii-lxviii)
He explains, “this I mention here, that others also may examine my logic by the same test, or be enabled to see, whether the logics recommended by others, will stand the trial or not. I myself have experienced the power of prejudice with respect to logic, in the case of aiming at certainty, and seeing things with our own eyes. And in the first place, I have analyzed mathematical demonstrations, and found, I never had any instance, the ground or reason of which I could not assign from my logic. And hereby I discovered, that my logical rules are, that which a regular and complete demonstration is in mathematics, particularly in geometry; and thus I have been convinced, that they are a just sample of the mathematical method.” (Pg. lxxxi-lxxxii)
In His Preliminary Discourse, he states, “Among possible things, we must admit of one necessary, self-existent Being, otherwise something would be possible, of which no sufficient reason could be assigned, contrary to what was established above… This self-existent Being we call God. Other things, which have the reason of their existence in the self-existent Being, we call Creatures. Now, as the business of philosophy is to assign the reason of the possibility of all things, the doctrine concerning God claims preferably an inquiry, previous to that of the Creatures; an accurate knowledge of which last is to be reduced into, or rather deduced from, their first principles. Though indeed we readily admit we must have a previous common or vulgar knowledge of them, but which we have no occasion to draw from philosophy, as from our early years we have it from experience. That branch, therefore, of philosophy, which treats concerning God, and the origin of the Creature, is called Natural Theology.” (XI, pg. 5-6)
He says, “We either proceed no farther in our knowledge than the powers, which produce effects in nature, or we advance one step farther still, namely, in accurately measuring the quantity, both of the powers, and of the effects, in order to shew, that certain powers may produce certain effects. For instance, either we rest satisfied with knowing, that the air, violently compressed, can force water to a considerable height in a fountain, or we attempt accurately to discover the degree of force imparted to the air, when compressed to the half, the third, the fourth, etc., of its former space, and how many feet high it forces the water in each case. This last degree of knowledge requires the measuring of things, that have quantity. With this view Mathematics were invented… And thus mathematics lead us to the most accurate and perfect knowledge possible to be attained.” (XV, XVI, pg. 7-8)
He asserts, “As everything, if we except the self-existent Being, has a sufficient reason why it is, rather than is not; or at least why it can be, or be possible; so things may admit of a real, which admit not of a nominal definition: As for instance, no properties, or no marks intrinsical determinations can be assigned, by which to distinguish Pleasure from all other alterations happening in the mind; yet, notwithstanding it may be shewn, how it arises; namely, when we are sensible of a degree of Perfection in ourselves, or, at least, imagine, we are sensible of it.” (Ch. I, XLVII, pg. 45-46)
He explains, “By these Syllogisms we investigate what is discoverable by human understanding, and demonstrate to others whatever they want to be convinced of, in order to a manifestation of its truth, though we have not always distinctly before our eyes, either in investigating, or in demonstrating, the Syllogistic form or method. But whoever duly attends to himself, when mediating or demonstrating, will be abundantly convinced thereof. My writings, both mathematical and philosophical… paved the way to a solid knowledge of Nature and Art, are a sufficient proof of this… Let no one imagine, that a proof can be completed in a single Syllogism. For as we admit the Conclusion, only on account of the Premises, we cannot be assured of its Truth, till we are convinced of the Justness of the Premises. And therefore the Premises are so long to be proved by other Syllogisms, till we come to such a Syllogism, as has for its Premises either Definitions, Axioms, clear Principles taken from experience, or Propositions previously demonstrated.” (Ch. VI, XX-XXI, pg. 90-91)
He acknowledges, “Now I foresee it will be alleged by the Sneerers at Syllogisms, that it is impossible to discover any thing by their means, as the Conclusion, which I am to find, must be known, before ever I can form the Syllogism. That which therefore is to be found, must be known, before it can be found, which is manifestly absurd. But does not the formation of Syllogisms… plainly shew, that we first know the Premises, and that they may come together into our minds, before ever we have thought of the Conclusion?... the whole of the Algebraic Calculus, by means of which so many discoveries are at this day made in the Mathematics and their kindred Sciences, is performed by pure, Formal Syllogisms; but only shew the manner, in which the above geometrical Theorem was discovered by means of such Syllogisms.” (Ch. VI, XXIV, pg. 97-98)
He observes that “things are very often other than, or different from, what they appear to us. And therefore we must be on our guard, not to judge directly, that things are really such, as they happen to strike our Senses: For thence have arisen numerous prejudices and errors, which have checked the progress of the Sciences, and have been so much the more zealously maintained by the Learned, as they imagined, they had Experience in their favor. Thus most people imagine, that the Earth is the Center of the World, and the only habitation for rational creatures; that the Heavens are the Canopy over our heads; and that the Sun and Stars move round us in twenty-four hours; as all this appears to our Eyes. And therefore it is of great service, to learn by what laws the Representations of things are formed in our Senses…” (Ch. V, XIV, pg. 120)
He argues, “we assume in the doctrine of Morality, that a Trust in God ought to be raised in the mind of a certain person. Now if I enquire, what is Trust in God, I find, that it arises from a certain persuasion, that God both knows in what manner to help, and that he can and will help. And therefore I recollect all that I know concerning God, and among other things I find, that he is all-knowing and all-wise, all-powerful and all-good. And here it occurs, that he who is all-wise and all-knowing, knows how to help; he who is all-powerful, can help; and he who is all-good, will help. And thus I thence conclude God knows how to help, and can and will help. From this I plainly see, that in order to bring a person to trust in God, we must give him a distinct notion of God’s omniscience, wisdom, power and goodness, and bring him to a conviction of these divine attributes. In the doctrine of Morality and Politics we shall have the Solution of many Problems in this manner.” (Ch. VI, VI, pg. 128-129)
He notes, “And therefore, as the Mathematics are the only Science almost in which hitherto strict Demonstrations have obtained; so the surest means to arrive at Science, is the serious and indefatigable Application to them at first, and then, as much as may be, introducing to the other Sciences the Mathematical Method: I say on purpose, as much as may be; for this Method does not succeed in all cases; and where it does, it carries us to excessive Prolixness, if we would keep up in all things to the rigor of it.” (Ch. VII, II, pg. 140-141)
He acknowledges, “But what is an Opinion to some, is not so to all; for One may be certain of what appears to Another but probable. And thus he has either the Science, or demonstrative Knowledge thereof, or he plainly sees it is an Error. So persons of Penetration are aware, that the common Opinion concerning the Essence of body is an Error, for they find, that the power of Resistance is common to all bodies, which on no account depends on Extension. Again it is possible, that some may deem bare Opinions to be undoubted Truths; namely, if they neither understand the nature of a just Demonstration, nor are duly exercised in the practice of Meditation and reflection, nor employ a sufficient time in Discussion… Now as we have no demonstration of Opinions, but assume in the proof some Propositions, which cannot be fully proved, there always remains a fear or suspicion, that the contrary may be true. And thus Opinions yield the mind no complete satisfaction, especially that of an intelligent Person, and one ardently desires after Truth.” (Ch. VI, XX-XXII, pg. 147-148)
He asserts, “If we cannot perceive from a Book, whether the Author extends his Propositions beyond the due limits of Experience, or adduces Propositions with Proof, which otherwise ought not to be admitted, or presupposes such Propositions in his Proof, as are less known, or at least less familiar to the Reader; such a book is INACCURATE. On the contrary, if every particular is sufficiently explained and proved, the book is ACCURATE.” (Ch. X, XVI, pg. 179-180) He adds, “In fine, if the following Propositions are connectedly drawn from the foregoing, as is usually done in Mathematics, every thing hangs well together. And the contrary, if not.” (XXI, pg. 181)
He contends, “Now as to the Holy Scriptures in particular, the Spirit of God does not usually excite the Notions in our Minds immediately, which we are to join with his Words” As in that Case there would be no necessity of translating the Original Text into other Languages, as it would suffice to read with an earnest desire of understanding the Scriptures, and of applying them to our own State, for the Holy Spirit to produce in us these Notions. But this is contradicted by Experience… And thus, God as well in his Word, as any other intelligent Writer, must either explain, what Thought or Notion we are to join with this or the other Word, or he must presuppose no other Notion, but what we have had before.” (Ch. XII, II-IV, pg. 188-189)
He states, “Now as in other particular dispositions, by what names soever called, one Man excels another, just so in the Powers of Understanding, one Man is more qualified for the Operations therefore than another. If therefore two Persons, with different natural Abilities, apply to the study of Logic, and give equal diligence to acquire a Habit of the practice of it, yet one shall far outstrip the other… If then we would distinctly determine the preeminence of natural Logic to Artificial, we must say, a Person naturally more qualified for the Operations of the Understanding than another, yet both employing and equal degree of application in the study and practice of Logic, the former will far excel the latter. Whence it follows no in the least, that we must prefer the natural to the artificial Logic; as this last explains, in a distinct manner, the Rules of the Natural, and besides, enables us to raise our natural Aptitude to a Habit.” (Ch. XVI, III, pg. 215-216)
In philosophy, Wolff is much overshadowed by Leibniz and Kant (he dates chronologically in-between them). And it is much harder to obtain translations of his works. (And this particular edition---a photostatic reprint, where an older book was obviously just placed on the photocopy machine, even if the “margins” are sometimes unreadable---is pretty bad, I must admit.) Still, he was a historically important figure in the German Enlightenment, and serious students of the history of philosophy may find his works interesting.
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