The Online Library of Liberty

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• Introduction
• A Note On the Text
• Acknowledgments
• A Compend of Logic
• Dissertation On the Origin of Philosophy and Its Principal Founders and Exponents 1
• Prolegomena the Definitions and Divisions of Logic
• Part I: On Apprehension
• Part II: On the Noetic Judgment and the Proposition
• Part III: On Discourse
• Appendix On Topics, Fallacies, and Method
• A Synopsis of Metaphysics Comprehending Ontology and Pneumatology Second Enlarged Edition
• Part I: On Being and the Common Attributes of Things
• Chapter 1: On Being ( De Ente )
• Chapter 2: On the Axioms of Metaphysics
• Chapter 3: On the Properties of Being
• Chapter 4: On the Principal Divisions of Being
• Chapter 5: On the Categories and the General Properties of Being
• Part II: On the Human Mind
• Chapter 1: On the Powers of the Mind, and First On the Understanding
• Chapter 2: On the Will
• Chapter 3: Whether Spirit Is a Different Thing From Body
• Chapter 4: On the Union of the Mind With the Body, and On a Separate State 1
• Part III: On God
• Chapter 1: In Which It Is Shown That There Is a God
• Chapter 2: On the Natural Virtues of God
• Chapter 3: On the Divine Virtues Concerned With Understanding
• Chapter 4: On the Will of God
• Chapter 5: On the Operations of God
• On the Natural Sociability of Mankind
• Inaugural Oration

PART III

On Discourse

CHAPTER 1

When the relation or connection of two ideas or terms cannot be directly perceived, the relation between them will often be able to be seen by a comparison of both of them with some third or middle [idea or term] or with several middle [ideas or terms] which are clearly connected with each other. This mental process is dianoetic judgment or discourse.

When there is only one middle, we are said to have a syllogism; when there are several middles connected with each other, by which the comparison of the terms is made, it is a sorites, or complex form of reasoning.1 First, therefore, we must deal with the simple and categorical syllogism, for the other more complex forms may be reduced to syllogisms.

A syllogism is “discourse in which a third proposition is inferred from two propositions rightly arranged.”

Before a proof is given by means of a syllogism, there is a question or problem of showing the relationship between two terms. These terms are called the Extremes; they are the Major term and the Minor term. The Major term is “the predicate of the question” or of the conclusion, and the Minor term is “the subject of the question.” The Middle Term is that which is compared with both of the extreme terms in the premissed propositions.

Irrespective of the content of the syllogism, there are these three terms: the Major, the Minor, and the Middle Terms. Taking account of the content, there are three propositions: the Major Proposition, the Minor Proposition (these are also called the Premisses), and the Conclusion. They are distinguished not by their order but by their nature.

1. The major proposition “is that in which the major term is compared with the middle term” and is called the proposition par excellence.

2. The minor proposition is that “in which the minor term is compared with the middle term” and is called the assumption or subsumption.

3. The conclusion is that “in which the extremes are compared with each other,” and the middle term never appears here.

CHAPTER 2

The whole force of the syllogism may be explained from the following axioms.2

Axiom 1. “Those things which agree with a single third thing agree with each other.”

2. “Those of which one agrees and the other does not agree with one and the same third thing, do not agree with each other.”

3. “Those which agree in no third thing, do not agree with each other.”

4. “Those which do not disagree with any third thing, do not disagree with each other.” From these [axioms] the general rules of syllogisms are deduced. The first three are about the quality of propositions.

Rule 1. If one of the premisses is negative, the conclusion will be negative (by axiom 2).

Rule 2. If both the premisses are affirmative, the conclusion will be affirmative (axiom 1).

Rule 3. From two negative [premisses] nothing follows because those which agree with each other and those which disagree with each other may both be different from a third.

Two [rules] on the Quantity of Terms:

Rule 4. The middle must be distributed once, or taken universally; for a common term often contains two or more species which are mutually opposed to each other, and from which predication may be made according to different parts of its own extension; therefore terms do not truly agree with a third term, unless one at least agrees with the whole of the middle.

Rule 5. No term may be taken more universally in the conclusion than it was in the premisses, because an inference from particular to universal is not valid.

On the Quantity of Propositions:

Rule 6. “If one of the premisses is particular, the conclusion will be particular.” For (i) suppose the conclusion is affirmative: therefore (by rule 1) both premisses are affirmative; but no term is distributed in a particular [premiss]; therefore (by rule 4) the middle term has to be distributed in the other one; it is therefore the subject of a universal affirmative; therefore the other extreme is also taken particularly, since it is the predicate of an affirmative, ergo, the conclusion will be particular (by rule 5). (ii): Suppose the conclusion is negative: therefore, its predicate is distributed; hence (by rules 5 and 4) both the major term and the middle term have to be distributed in the premisses, but (rule 3) when one premiss is negative, the other is affirmative. If one [premiss] is particular, only these two terms can be distributed; when one premiss is affirmative, the other should be particular. Therefore the minor extreme, the subject of the conclusion, is not distributed in the premisses; therefore (by rule 5) it is not distributed in the conclusion.

Rule 7. “From two particulars nothing follows,” at least in our normal way of speaking, according to which the predicate of a negative is taken to be distributed. For (i) if the conclusion is affirmative and both premisses are affirmative, no term in the premisses is distributed (contrary to rule 4). (ii) Suppose the conclusion is negative; therefore some predicate is distributed, but the predicate is distributed only in particular premisses; it will therefore be invalid (contrary to rule 4 or 5).

Rules 1 and 7 are thus reduced to one rule. The conclusion follows the weaker side, i.e., the negative or particular. All the rules are contained in these verses:3

• You must distribute the middle, and there should be no fourth term.
• Both premisses should not be both negative and particular.
• The conclusion should follow the weaker side;
• And it may not be distributed or negative, except when a premiss is.4

In a curious and unusual manner of speaking, a certain negative conclusion may be reached, with the predicate undistributed, as in this example:

• Certain Frenchmen are learned,
• Certain Englishmen are not learned,
• Therefore,
• Certain Englishmen are not certain Frenchmen.

CHAPTER 3

A figure of a syllogism is “the proper arrangement of the middle in the premisses”; there are only four figures.

1. That in which the middle is the subject of the major and the predicate of the minor.

2. That in which the middle is the predicate of both.

3. That in which the middle is the subject of both.

4. That in which the middle is the predicate of the major and the subject of the minor.

In the first [the middle is] sub[ject and] pre[dicate]; in the second [it is] twice a pre[dicate]; in the third [it is] twice a sub[ject]; and in the fourth [it is] pre[dicate and] sub[ject].

The mood of the syllogism is “the correct determination of the propositions according to quantity and quality.”

Sixty-four arrangements are possible of the four letters A, E, I, O; of these, fifty-two are excluded by the general rules. There remain, therefore, twelve concluding modes of which not all lead to a conclusion in every figure because of the nature of the figure; and some are not useful at all.

CHAPTER 4

The special rules of the figures are as follows.

1. i. In figure 1 the minor [premiss] must be affirmative; if it were negative, the conclusion would be negative (by rule 1), and its predicate would be distributed. But the major would be affirmative (by rule 3), and its predicate would not be distributed; hence there would be a fallacy (contrary to rule 5).

ii. The major [premiss] must be universal. For the minor is affirmative (from the former rule), and therefore its predicate is particular, namely the middle term. It must therefore (by rule 4) be distributed in the major of which it is the subject. These things will be more easily made clear by the schema below, where the letters denote distributed terms.5

Here are examples of fallacies.

N.B. Capital letters denote distributed terms; lowercase letters particular terms.

2. Rules of the second figure:

i. One of the premisses must be negative. For since the middle term is predicated of both, it would be distributed in neither if both were affirmative (contrary to rule 4).

ii. The major must be universal. For the conclusion is negative, and its predicate is distributed. It must therefore (by rule 5) be distributed in the major of which it is the subject.

3. Rules of the third figure:

i. The minor must be affirmative, for the same reason as in the previous figure.

ii. The conclusion must be particular. For since the minor is affirmative, its predicate, the minor term, is not distributed; therefore (by rule 5) it is not distributed in the conclusion of which it is the subject.

Examples of fallacies:

4. Rules of the fourth figure:

i. “If the major is affirmative, the minor must be universal”; otherwise it will contravene rule 4.

ii. If the conclusion is negative, the major must be universal; otherwise it will contravene 5.

iii. If the minor is affirmative, the conclusion must be particular, for the same reason as in the third figure.8

CHAPTER 5

The concluding modes in the four figures are six.

1. AAA, EAE, AII, EIO, *AAI, *EAO.

2. EAE, AEE, EIO, AOO, *EAO, *AEO.

3. AAI, EAO, IAI, AII, OAO, EIO.

4. AAI, AEE, IAI, EAO, EIO, *AEO.9

Thus there are two [modes] in the first [figure], two likewise in the second, and one in the fourth, which are useless and have no names, because they make a particular inference where the valid conclusion would be universal.

The named modes are contained in these verses:

• Barbara, Celarent, Darii, and Ferio are of the First;
• Cesare, Camestres, Festino, Baroko are of the Second;
• The Third claims Darapti and Felapton,
• And includes Disamis, Datisi, Bocardo, Ferison.
• Bramantip, Camenes, Dimaris, Fresapo, Fresison,
• Are of the Fourth. But the five which arise from the five universal [modes]
• Are unnamed, and have no use in good reasoning.

Here are examples of the modes according to the vowels which are contained in the words [of the mnemonic], A, E, I, O.

CHAPTER 6

From axioms 1 and 2 (p. 32) the force of the inference in all of these modes will be clear, since both of the extremes are compared with the middle, and one of them with the distributed middle; and either both agree with it, or one only does not agree.

The Aristotelians neatly demonstrate the force of the inference, and perfect the syllogisms, by means of reduction, since the validity of all [the syllogisms] in figure 1 is evident from the dictum de omni et nullo (see p. 26); they also give, in their technical language, the rules of conversion and opposition, by means of which all the other modes can be reduced to the four modes of the first figure, which Aristotle calls the perfect [modes].10

There are two kinds of reduction, ostensive and ad absurdum. The initial letters in each of the modes (B, C, D, and F) indicate the modes of the first figure to which the modes of the other [figures] are to be reduced, i.e., those of which the initial letter is the same.11 S and P following a vowel show that that proposition is to be converted, S simpliciter, P per accidens. M shows that the propositions are to be transposed, K that the reduction is made per impossibile, of which more later. When this is done, the conclusion reached will be either the same as in reducing Cesare, Festino, etc., or [a conclusion] which implies the same conclusion, or the contradictory to the conceded premiss. The validity of an ostensive reduction is known from the rules of conversion and subalternation.

Reduction to the impossible is as follows. If it is denied that a given conclusion follows from true premisses, let the contradictory of the conclusion be substituted for the premiss whose symbol includes a K, like the major in Bokardo and the minor in Baroko; these premisses will then show in Barbara the truth of the contradictory of the premiss which was claimed to be true. If therefore the given premisses had been true, the conclusion would also have been true; for if it was not, its contradictory would have been true, and if that had been true, it will show (in Barbara) that the other premiss is false, contrary to the hypothesis.

For these rules of syllogisms to hold, we have to look carefully for the true subjects and predicates of the propositions, which are sometimes not at all obvious to beginners; and then we have to determine whether they are really affirmative or negative as they are used in the argument. For in complex [propositions], sometimes one part is negative, the other is affirmative, and occasionally it is the negative part (the less obvious part) which is chiefly in point. For example,

Therefore

Everything different from God may err, }

Every council is different from God. }

Likewise,

All Holy Scripture is worthy of belief, }

Mathematical proof is not Holy Scripture. }

And the dictum de omni et nullo is so useful in proving a true argument and detecting a false one, that by its help any intelligent person may be able to see both true syllogistic force and its fallacious semblance, according to whether one of the premisses contains the conclusion or not, even before applying the special rules of syllogisms.

CHAPTER 7

With regard to the remaining forms of argument, it is evident that they are imperfect syllogisms or may be reduced to imperfect syllogisms.

1. The enthymeme12 or rhetorical syllogism is “when one of the premisses is unspoken because it is quite obvious”; it is for this reason that an enthymematic judgment has full syllogistic force.

2. Induction is “an inference from various examples,” of which the chief use is in physics, in politics, and in household matters. It does not generate the highest credit or exclude all fears of the contrary, unless it is clear that there are absolutely no contrary examples.

3. An epicheirema13 is “a complex syllogism in which a confirmation is attached to one or both of the premisses.”

4. Sorites is “discourse which contains several syllogisms which are connected with each other,” or where there are several middle terms which are connected with each other or with the extremes in several propositions of which if even one is negative, the conclusion will be negative, and if two are negative or any middle term is not distributed at least once, there will be no inference.

5. A dilemma is “a kind of epicheirema, where in making a division, that which is shown about the individual parts in the premisses is concluded of the whole.”

6. A hypothetical syllogism is “one in which one of the premisses is hypothetical”; when the minor is hypothetical, so also is the conclusion; these also serve to prove the inference in an enthymeme. More frequent are those in which the major is hypothetical, for example:

But since a more general predicate follows from any of the corresponding kinds (for example, If it is a man, if it is a horse, etc., it will also be an animal), but from a general predicate, no one particular species will follow (for from the fact that it is an animal, it does not follow that it will be a horse or an ass), it is evident that hypothetical syllogisms rightly proceed (1) from the positing of an antecedent to the positing of a consequent, or (2) from the removal of a consequent to the removal of an antecedent.

It is a fallacious inference from the removal of an antecedent, or the positing of a consequent:

The positing of a negative will be a negation, and the removal of it an affirmation.

Hypothetical [syllogisms] are reduced to categorical [syllogisms] by this general method: “every case which posits that Titius is a man, posits that he is an animal; but every case, or some case, posits that he is a man; therefore, etc.” But often it may be more easily and briefly done when there is either the same subject or the same predicate to the antecedent and the consequent; for example:

• • If man is an animal, he has sensation,
  • But every man is an animal, therefore he has sensation.
• • Every animal has sensation.
  • Every man is an animal; therefore,
  • Every man has sensation.
  • If every animal has sensation, every man has sensation;
  • But every animal has sensation; therefore,
  • Every man has sensation.

7. Disjunctive syllogisms are “those in which the major is disjunctive, [whether] affirmative or negative.” Either it is day, or it is night; but it is not day, therefore it is night. Or, it is not both night and day, but it is day; therefore it is not night. The force of the inference is obvious enough, when by positing an affirmative disjunctive major, an affirmative conclusion is drawn from a negative minor; or from a copulative negative major and an affirmative minor, the conclusion is negative. For in the former case the syllogism will be reduced to Barbara.

• • All time different from daytime is night;
  • But this time is different from daytime.
  • Therefore …
• • In the other case.
  • No daytime is night,
  • But this time is day.
  • Therefore …

There is no inference from an affirmative minor, in the former, or from a negative [minor] in the latter.

CHAPTER 8

As far as content is concerned, syllogisms are either certain or probable depending on their premisses.

A demonstration is “an argument duly reaching a conclusion from certain premisses,” and it is either ostensive, or leading to absurdity; the latter is the case when the contradictory of a proposition is shown to be false, from which it will be clear that it is itself true. The former is either a priori, or of a cause,14 “when an effect is shown from a known cause.” But there are causes of being and causes of knowing. The former are prior by nature and per se; the latter [are prior] in being known and in relation to us. Demonstrations drawn from both kinds of causes are called a priori, but especially those which are drawn from things prior by nature.15

“The discipline which relies on demonstrations” is science. The general rules of science are

1. “All terms must be accurately defined,” nor is their meaning ever to be altered.

2. “Certain and evident axioms are to be posited.”

3. “One must proceed from the better known to the less known by demonstrations step by step,” and premisses which go beyond axioms and propositions previously demonstrated are not to be admitted.

Demonstrations only deal with abstract propositions, especially in geometry and arithmetic.

There is no single principle of human knowledge which you may rightly say is prior to the rest. There are many evident principles apart from the most general axioms. Nor will any syllogism carry full credence unless both terms of the conclusion are found connected with the middle term in evident propositions. In demonstration, therefore, through several syllogisms which are connected in a continuous series, the number of evident propositions will exceed the number of middle terms by one.

In absolute propositions, and in those which are chiefly useful in life, there is another way of knowing which has its own proper evidence, albeit different from demonstrative [evidence]. Absolute propositions asserting that things exist are known (1) by consciousness, (2) by sense, (3) by reasoning, or by an observed link with existing things, or (4) by testimony. Other experiential truths about the powers and qualities of things are chiefly learned by experience, and by a varied acquaintance with life, and by induction; and whenever any example is similar, it should, other things being equal, be included with the larger rather than the smaller number. For rarely can men see any connection among the actual powers and qualities of things.

There are innumerable degrees of likelihood, from the slightest probability to full and stable assent; from the judicious appreciation [of their degrees] grave men are more likely to earn a reputation for prudence and wisdom than from cleverness in the sciences.

“Assent given to arguments which are probable but do not achieve the highest likelihood” is called opinion. Where either of the premisses is uncertain, there is only a probable conclusion; hence in a long chain of arguments, the result will be a very weak assent.

Arguments which create belief are either artificial and involve the use of reasoning, or inartificial, from testimony. “In recent [writers]16 assent resting on testimony is belief (par excellence).” Belief is either divine or human, depending on whether the assent rests on the testimony of God or of men.

Divine belief will be a fully firm assent when it is clearly established that God has revealed something, since a superior nature cannot deceive or be deceived.

Human belief too, although often hazardous, may sometimes attain full certainty, when it is clear that the witnesses could not have been deceived, and could not have intended to deceive others, so that neither their knowledge nor their reliability nor their truthfulness is in doubt.

Sometimes the knowledge of witnesses will be evident from the nature of the matter in hand; and their reliability will be established if they have not been induced to give testimony about the question in hand by any reward or other inducements; even more so when they testify to their own peril or loss, and could not expect to persuade others, if they themselves knew that the thing was otherwise.

If testimony is not liable to any suspicion of fraud or ignorance, belief may be given (1) to facts which cannot be known in any other way; (2) also to things totally different from what we have previously observed, if indeed there are no internal arguments that prevent belief; (3) and third, even to things that are strange and contrary to all our experience or observation, provided the testimony deals with material and circumstances that are different and remote from our own affairs.

Appendix on Topics, Fallacies, and Method

CHAPTER 1

On Topics

The doctrine of topics, which should not perhaps be ignored by orators, who often have to marshal a large array of arguments to create or confirm belief, is not so useful for logicians, whose art aims chiefly at developing or teaching sciences in which nothing further needs to be added to any valid argument.1 In any case, topics are “certain general heads of arguments, or the names of the genera in which they are found.” Each science or art has its own topics, together with the actual [art] of teaching them. Only the broadest genera need to be treated by the logician.

I. The topics of grammar are drawn either from the meanings of words or from etymological connections; critics have further [topics], which are the rules of interpretation.

II. The topics of logic are:

1. From definition: what the definition agrees with, that also the thing defined agrees with, and vice versa. What the definition does not agree with, neither does the thing defined [agree with], and vice versa.

2. From division (which are also the topics from the genus): (i) A logical part being posited, i.e., a species, the whole too is posited, i.e., the genus, but not the other way about: He is a man, therefore also an animal. (ii) Another topic is the dictum de omni et nullo. (iii) What may be predicated of individual parts, is true of the whole, if something is not collectively negatived; or negation of parts affects the totality or whole number.2

3. From genus and species: (i) when the species is posited, the genus is posited, and (ii) when the genus is removed, the species is removed; but neither will hold vice versa.

4. From differentia and property: (i) With whatever either one of these agrees under the same nearest genus, the species also agrees, and vice versa. (ii) Anything of which either one is denied, the species is also denied of it.

5. From accident: when an accident is posited, a substance is posited, but not vice versa.

6. From things which are opposed, whether complexly or incomplexly. The rules given above are so many topics.

III. Metaphysical topics:

1. From the whole and the part: when a physical whole is posited, all the combined parts [of it] are posited, and when these are posited and combined, the whole is posited.

2. The part is less than the whole both in quantity and dignity. Topics here may include those from definition, genus and species, depending upon different understandings (acceptio) of the whole. Metaphysical topics also include all the axioms about efficient causes.

IV. Ethical topics are nearly all ends, especially ultimate ends, but there are also the different species of the fitting and the good; and when we learn these from the topics, we also learn the virtues, duties, natural laws, and different degrees of goodness and badness. Arguments are also drawn from men’s appetites and from natural desires to demonstrate laws and to dissect questions of fact, since all plans of action derive from these. The axioms are as follows:

(1) The more that dispositions, intentions, and habits of mind contribute to human advantage, the better they are. And (2) the more they facilitate the assaults of evil, so much the worse they are. (3) Things which are commended by men’s higher desires, which are more proper to man, and which exercise the faculties which are proper to man, are better than those which we share with the beasts. (4) All things gentler and kindlier are, other things being equal, more worthy of a good man, all contrary things are unworthy, and so on.

In questions of fact we should chiefly look at the Cassian query: “Who benefits?”3 These are the axioms: (1) No one is gratuitously either bad or deceitful. (2) No one deliberately acts against the obvious advantage of himself and his own, except in hope of a greater advantage or from a specially strong sense of duty. (3) No sane man, however evil, attempts to deceive, when he has no reason to expect that his deceit will succeed. (4) No sane man is mistaken in things which are exposed to a long and full scrutiny by his senses.

V. The topics of physics are also “from ends,” for the perfect work whether of nature or of art which is that which is most suited to the ends it sets itself. We make best progress in the knowledge of things by combining experiments and geometrical reasoning.

CHAPTER 2

On Fallacies and Sophisms

I. The causes of errors lie either in the will or in the understanding, though the understanding is also to some extent influenced by defects of the will.

[Errors] of the [will] are haste or rashness, bad passions and emotions. For where there is no sincere zeal to know the truth and a love of goodness, a man will soon tire of careful and painstaking inquiry; he will turn his mind to other pursuits or pleasures, content with an immediate appearance of truth, however deceptive. Where there is party zeal or pride or indolence, men will remain stuck in their childhood prejudices or in the opinions favored by the sect to which they have attached themselves, and assail with senseless passion all those who hold contrary opinions, however innocent those opinions may be and truer than their own. When a man anticipates honor or riches from a vigorous defense of his sect, oil is poured on the flames; and the arrogance of a proud person is deeply wounded if anyone who disagrees with him assumes he has deeper insight, and appears to be accusing him of ignorance or low intelligence.

Men are also too quick to take up beliefs which contribute to their own advantage or pleasure; arguments in the other direction are either ignored or weighed on an unequal balance.

II. The causes of the errors which afflict the understanding are slowness of mind (which however can be quite well remedied by hard work) and the deceptive appearances of things. Deceptive appearances are either axioms or principles, rashly picked up and not always true, or terms which are confused, or of indeterminate meaning, and frequently altered without our knowledge. These are the sources of fallacious arguments or sophisms.

Paralogisms openly err in the form itself. Sophisms seem to retain legitimate form, but contain either false or ambiguous propositions or conceal a fault of form under a misleading veil of words.

III. The Aristotelians count thirteen classes of sophisms, six in diction and seven outside of diction.4 Of sophisms in language, the first and second are equivocations in words, or ambiguities in expression or speech. Casual equivocations do not even deceive children, but confused terms may deceive even the learned: this is the great value of definitions.

The third and fourth [linguistic sophisms] proceed from a divided sense to a compound sense, or from a compound sense to a divided [sense]. Thus it would be wrong to infer that the wicked are approved by God, or that God delights in them while their wickedness persists, [simply] because they please him when their character changes, or that the blind can see or the deaf hear, because they can do so when cured.

The fifth and sixth are sophisms of nuance, or figurative expression, which will not deceive anyone unless he is very careless.

IV. The seven fallacies outside of diction are these:

1. From the accident to the thing itself. Thus the Epicureans badly argued that God has a form because neither virtue nor reason is seen without form; it is also incorrect to condemn all use of wine and all civil power because serious evils arise from their abuse.

2. From the qualified statement to the simple statement. Thus it would be wrong to infer that reasoning, discourse, and restraint of emotions should be ascribed to God because they are perfections and virtues; or to argue that because these things cannot be ascribed to God, therefore there is not in God every virtue and perfection. Riches do harm to the wicked; therefore they are simply bad in their kind.

3.Ignoratio elenchi occurs when one believes that a dispute can be resolved by proving something about which both sides agree. Thus, they will say that all the pagans will perish for ever, because no one can be saved except through Christ, when what needed to be proved was that no one could be saved through Christ who did not know him. Thus some men attempt to show that taking up arms against tyrants is always wicked, because it is illicit to resist a legitimate ruler.

4. Not causes for cause: for example, nature everywhere abhors a vacuum; therefore water in pumps will rise to any height you please. Seditions and factions are more frequent in free states; therefore liberty must be proscribed. Greed and many other evils arise from private property; therefore it is desirable to have community of property. Any free man will make mistakes in using his own judgment; therefore it is not to be permitted.

5. The fallacy of the consequent. Examples of this even include mistakes by quite learned people: bodies projected directly upward fall straight back to the place from which they were projected; therefore the earth does not move: and a thousand others.

6.Petitio principii, when what has to be proved is assumed as given. For example, the following “proof ” of the Ptolemaic system: the center of the universe is the point to which all things are borne by their own weight; but all things that we see are borne toward the earth; therefore, etc.

7. The fallacy of more than one question, of which examples are afforded by questions about exclusive, inceptive, and desitive5 propositions.

CHAPTER 3

On Method and Logical Practice

I.6 One method is the way of discovery, which is also called the analytic [method]; the other is the way of teaching, and is the synthetic [method]. Both may be either professional and academic, or public and popular.

The analytic [method], beginning from consideration of singular or more complex [things], or from effects or from a proposed end, proceeds to general, simple [things], to causes, means, and origins. The synthetic [method] proceeds in the opposite order, from the latter to the former.

Principles of knowledge are included among causes, as well as what are properly called causes of being.

The synthetic [method] first proposes definitions, then postulates and axioms, and simpler and easier propositions; and when these have been proved, it proceeds by way of them to more complex and difficult [propositions], following the rules of demonstration given above. Writers of geometry afford examples of both methods.

II. Logical practice consists in the treatment of themes.7

A theme is anything that can be put forward for the understanding to grasp. It is either simple, or a term of some kind; or it is complex, that is, a proposition or statement which has to be confirmed or explained.

In treating a simple theme, (1) we must first explain the origin of a complex word or term and its different meanings and particularly the sense which we want, then (2) its essential attributes, whether primary or secondary, and its more prominent accidents. (3) We must also discuss their origin and end and their causes, if the subject allows it, and (4) the relations existing between it and other things. (5) It is to be divided into its parts, either logical or physical, if there are any.

III. The treatment of a complex theme is either solo or social.8 The solo treatment consists either of exegesis or of analysis. There is exegesis of the proposition or illustration of its effect, and there is confirmation. There is analysis of the exegesis or the resolution into its parts of a longer piece which someone else has written, and its explication.

There are three chief parts of exegesis: (1) paraskeue or preparation, which explains the terms of the question, settles its status, and puts forward the major opinions of the learned. (2) There is kataskeue, or confirmation, which chooses the true view and confirms it by the best arguments, rebuts counterarguments, and cites the testimonies of learned men. (3) And finally there is anaskeue, which dissolves objections and either claims for the speaker’s side, or modestly refutes, the testimonies of famous men which seem to oppose it. Sometimes we should preface it all with a proparaskeue about the importance and occasion of the question; and sometimes there is an episkeue attached, which gives a summing-up, together with useful corollaries. But above all the rules, we should listen to the poet’s [advice]:

It is the function of an analysis to demonstrate in a given piece all these parts of exegesis and to explain them, or at least to reveal the true sense of the writer. One must therefore look at: (1) Who is speaking? (2) what about? (3) with what purpose and intention? (4) to whom? And (5) on what occasion? Finally, accounts should be given of the antecedents and consequents.

In treating a complex theme with a companion, or in disputation, the rules to be observed are easy and well known, and swiftly learned by practice.10

the end

A Synopsis of Metaphysics Comprehending ONTOLOGY and PNEUMATOLOGY

Second enlarged edition

1744

PART I

On Being and the Common Attributes of Things

[1 ]See Part III, chap. 7, p. 43.

[2 ]See Aldrich, Artis Logicae Compendium, III, 2, p. 4.

[3 ]Aldrich, Artis Logicae Compendium, cites this mnemonic in the same form at III, 3, p. 16.

[4 ]This paragraph was a footnote in Hutcheson’s text.

[5 ]The letters used in this chapter to denote distributed terms are not found in the mss. of Hutcheson’s “Logica,” nor were they employed by Aldrich. James Clow, in his lectures on Hutcheson’s logic, “A System of Logic,” p. 179, offered the following clarification of the symbols used by Hutcheson:

In the following Scheme, which Dr. Hutcheson, in the Compend, used to exemplify the Rules of the Figures, where the Capital Letters signify that the terms are taken Universally, and the small ones that they are taken Particularly, B or b represents the Major Term, D or d the Minor and M or m the Middle term. {=} is the Sign of an Affirmative Proposition, and {>} of a Negative one.

[8 ]Clow also identified in his lectures the modes of the four figures which are excluded by an application of the rules and those modes which remain valid: “A System of Logic,” pp. 179-83. Those modes of the four figures which remain valid or useful are summarized by Hutcheson in the first paragraph of chap. 5.

[9 ]Hutcheson considered the five modes marked by asterisks to be redundant. They are represented as subaltern modes in the figures that follow.

[10 ]See Sanderson, Logicae Artis Compendium, III, 5, pp. 132-37, and Aldrich, Artis Logicae Compendium, I, 3, pp. 20-21. The reader may find it helpful to compare Hutcheson’s presentation with the more elaborate commentary on Aldrich’s logic provided in John Huyshe, A Treatise on Logic, on the Basis of Aldrich, with Illustrative Notes.

[11 ]Thus C in Cesare indicates that it may be reduced to Celarent, Ferison to Ferio, and so on.

[12 ]Literally, something retained in the mind: where the syllogism is reduced from three propositions to two, an antecedent and consequent, the implicit premise must be made explicit for the argument to be tested by the figures and modes outlined above.

[13 ]Literally, to move one’s hand to a thing and thereby confirm it or to make an inference from common experience.

[14 ]Hutcheson writes this in Greek (tou dioti ); the terminology goes back to Aristotle, “Analytica Posteriora,” I, 13, 3: Organon, vol. 2, p. 669.

[15 ]See Sanderson, Logicae Artis Compendium, III, 5, p. 132, and Aldrich, Artis Logicae Compendium, I, 5, p. 32.

[16 ]For example, Locke, Essay, IV, XV, and XVI, pp. 654-68.

[1 ]Hutcheson’s examination of “topics” (treated at length by Aristotle: see Organon, II, pp. 357-540) appears rather to have been an abridgment of the treatment of this subject in Arnauld, The Art of Thinking, pt. 3, chap. 18, pp. 240-46, where topics taken from grammar, logic, and metaphysics were summarized. Hutcheson’s presentation added a fourth and a fifth set of topics, taken from ethics and physics.

[2 ]The numbers assigned topics 3, 4, 5, and 6 follow “Logica,” pp. 45-46. In the 1756 edition, these topics were numbered 4, 5, 6, 7; there was no number 3.

[3 ]Cui bono? “For whose good?” “Who benefits?” This is the question which L. Cassius Longinus (consul, 127 ) used to ask when sitting as a judge. The main source is Cicero, Pro Sexto Roscio Amerino 30 (84), in vol. 6, The Speeches.

[4 ]Aristotle, “The Sophistical Elenchi,” in Organon, II, pp. 540-608; Sanderson, Logicae Artis Compendium, III, 28, pp. 206-10, and III, 29, pp. 210-16.

[5 ]See Part II, chap. 5, p. 28, n. 8.

[6 ]The divisions of this chapter (I, II, III) derive from “Logica,” pp. 54-58. In the published text (1756) only Section II was marked.

[7 ]Hutcheson’s treatment of themes and of the rules for considering a simple theme rehearse the observations made on this subject by Gershom Carmichael, “A Short Introduction to Logic,” chap. 4, sec. 2, in Natural Rights, pp. 309-11.

[8 ]Hutcheson’s remarks on the solo treatment of a complex theme again reflect Carmichael’s observations in “A Short Introduction to Logic,” chap. 4, sec. 3, Natural Rights, pp. 311-12.

[9 ]From Horace, Ars Poetica, ll. 38-41, in Satires, Epistles, and Ars Poetica, p. 452.

[10 ]See Carmichael, “A Short Introduction to Logic,” chap. 4, sec. 4, in Natural Rights, pp. 312-15.