Changes

In any case, belief or knowledge is the feature of state that an agent of inquiry lacks at the moment of setting out.  Inquiry begins in a state of impoverishment, need, or privation, a state that is absent the quality of certainty.  It is due to this feature that the agent is motivated, and it is on account of its continuing absence that the agent keeps on striving to achieve it, at least, with respect to the subject in question, and, at any rate, in sufficient measure to make action possible.

In any case, belief or knowledge is the feature of state that an agent of inquiry lacks at the moment of setting out.  Inquiry begins in a state of impoverishment, need, or privation, a state that is absent the quality of certainty.  It is due to this feature that the agent is motivated, and it is on account of its continuing absence that the agent keeps on striving to achieve it, at least, with respect to the subject in question, and, at any rate, in sufficient measure to make action possible.

====1.4.3  The Modes of Inquiry====

====1.4.3. The Modes of Inquiry====

<blockquote>

<blockquote>

<p>Let the strange fact be granted, we say, that our hymns are now made into "nomes" (laws), just as the men of old, it would seem, gave this name to harp-tunes, - so that they, too, perhaps, would not wholly disagree with our present suggestion, but one of them may have divined it vaguely, as in a dream by night or a waking vision:  anyhow, let this be the decree on the matter:- In violation of public tunes and sacred songs and the whole choristry of the young, just as in violation of any other "nome" (law), no person shall utter a note or move a limb in the dance.</p>

<p>Let the strange fact be granted, we say, that our hymns are now made into "nomes" (laws), just as the men of old, it would seem, gave this name to harp-tunes, &mdash; so that they, too, perhaps, would not wholly disagree with our present suggestion, but one of them may have divined it vaguely, as in a dream by night or a waking vision:  anyhow, let this be the decree on the matter: &mdash; In violation of public tunes and sacred songs and the whole choristry of the young, just as in violation of any other "nome" (law), no person shall utter a note or move a limb in the dance.</p>

<p>(Plato, Laws, VII, 799E-800A).</p>

<p>(Plato, ''Laws'', VII, 799E&ndash;800A).</p>

</blockquote>

</blockquote>

Other names for descriptive laws are "declarative" or "empirical" laws.  Other names for prescriptive laws are "procedural" or "normative" laws.

Other names for descriptive laws are "declarative" or "empirical" laws.  Other names for prescriptive laws are "procedural" or "normative" laws.

Implicit in a descriptive law is the connection to be found or made, discovered or created, between past experience and present expectation.  What one knows about these connections is kept in a descrptive model.

Implicit in a descriptive law is the connection to be found or made, discovered or created, between past experience and present expectation.  What one knows about these connections is kept in a descriptive model.

Implicit in a prescriptive law is the connection to be found or made, discovered or created, between current conduct and future experience.  What one knows about these connections is kept in a prescriptive model.

Implicit in a prescriptive law is the connection to be found or made, discovered or created, between current conduct and future experience.  What one knows about these connections is kept in a prescriptive model.

If it were only a matter of doing propositional reasoning as efficiently as possible, I would simply use the cactus language and be done with it, but there are several other reasons for revisiting the syllogistic model.  Treating the discipline that is commonly called "logic" as a cultural subject with a rich and varied history of development, and attending to the thread of tradition in which I currently find myself, I observe what looks like a critical transition that occurs between the classical and the modern ages.  Aside from supplying the barest essentials of a historical approach to the subject, a consideration of this elder standard makes it easier to appreciate the nature and the character of this transformation.  In addition, and surprisingly enough to warrant further attention, there appear to be a number of cryptic relationships that exist between the syllogistic patterns of reasoning and the ostensibly more advanced forms of analysis and synthesis that are involved in the logic of relations.

If it were only a matter of doing propositional reasoning as efficiently as possible, I would simply use the cactus language and be done with it, but there are several other reasons for revisiting the syllogistic model.  Treating the discipline that is commonly called "logic" as a cultural subject with a rich and varied history of development, and attending to the thread of tradition in which I currently find myself, I observe what looks like a critical transition that occurs between the classical and the modern ages.  Aside from supplying the barest essentials of a historical approach to the subject, a consideration of this elder standard makes it easier to appreciate the nature and the character of this transformation.  In addition, and surprisingly enough to warrant further attention, there appear to be a number of cryptic relationships that exist between the syllogistic patterns of reasoning and the ostensibly more advanced forms of analysis and synthesis that are involved in the logic of relations.

=====1.4.3.1  Deductive Reasoning=====

=====1.4.3.1. Deductive Reasoning=====

In this subsection, I present a trimmed-down version of deductive reasoning in Aristotle, limiting the account to universal syllogisms, in effect, keeping to the level of propositional reasoning.  Within these constraints, there are three basic "figures" of the syllogism.

In this subsection, I present a trimmed-down version of deductive reasoning in Aristotle, limiting the account to universal syllogisms, in effect, keeping to the level of propositional reasoning.  Within these constraints, there are three basic "figures" of the syllogism.

In addition to this terminology, it is convenient to make use of the following nomenclature:

In addition to this terminology, it is convenient to make use of the following nomenclature:

1. The "Fact" is the proposition that applies the term in the first position to the term in the third or last position.

# The ''Fact'' is the proposition that applies the term in the first position to the term in the third or last position.

 

# The ''Case'' is the proposition that applies the term in the second or intermediate position to the term in the third or last position.

2. The "Case" is the proposition that applies the term in the second or intermediate position to the term in the third or last position.

# The ''Rule'' is the proposition that applies the term in the first position to the term in the second or intermediate position.

 

3. The "Rule" is the proposition that applies the term in the first position to the term in the second or intermediate position.

Because the roles of Fact, Case, and Rule are defined with regard to positions rather than magnitudes they are insensitive to whether the proposition in question is being used as a premiss or is being drawn as a conclusion.

Because the roles of Fact, Case, and Rule are defined with regard to positions rather than magnitudes they are insensitive to whether the proposition in question is being used as a premiss or is being drawn as a conclusion.

The "first figure" of the syllogism is explained as follows:

The ''first figure'' of the syllogism is explained as follows:

<blockquote>

<blockquote>

<p>When three terms are so related to one another that the last is wholly contained in the middle and the middle is wholly contained in or excluded from the first, the extremes must admit of perfect syllogism.  By "middle term" I mean that which both is contained in another and contains another in itself, and which is the middle by its position also;  and by "extremes" (a) that which is contained in another, and (b) that in which another is contained.  For if A is predicated of all B, and B of all C, A must necessarily be predicated of all C.  ...  I call this kind of figure the First.</p>

<p>When three terms are so related to one another that the last is wholly contained in the middle and the middle is wholly contained in or excluded from the first, the extremes must admit of perfect syllogism.  By "middle term" I mean that which both is contained in another and contains another in itself, and which is the middle by its position also;  and by "extremes" (a) that which is contained in another, and (b) that in which another is contained.  For if A is predicated of all B, and B of all C, A must necessarily be predicated of all C.  ...  I call this kind of figure the First.</p>

<p>(Aristotle, Prior Analytics, 1.4).</p>

<p>(Aristotle, ''Prior Analytics'', 1.4).</p>

</blockquote>

</blockquote>

There is the Case:

There is the Case:

"All canaries are birds." (C => B)

: "All canaries are birds." (C => B)

There is the Rule:

There is the Rule:

"All birds are animals." (B => A)

: "All birds are animals." (B => A)

One deduces the Fact:

One deduces the Fact:

"All canaries are animals." (C => A)

: "All canaries are animals." (C => A)

The propositional content of this deduction is summarized on the right.  Taken at this level of detail, deductive reasoning is nothing more than an application of the transitive rule for logical implications.

The propositional content of this deduction is summarized on the right.  Taken at this level of detail, deductive reasoning is nothing more than an application of the transitive rule for logical implications.

The "second figure" of the syllogism is explained as follows:

The ''second figure'' of the syllogism is explained as follows:

<blockquote>

<blockquote>

When the same term applies to all of one subject and to none of the other, or to all or none of both, I call this kind of figure the Second;  and in it by the middle term I mean that which is predicated of both subjects;  by the extreme terms, the subjects of which the middle is predicated;  by the major term, that which comes next to the middle;  and by the minor that which is more distant from it.  The middle is placed outside the extreme terms, and is first by position. (Aristotle, Prior Analytics, 1.5).

<p>When the same term applies to all of one subject and to none of the other, or to all or none of both, I call this kind of figure the Second;  and in it by the middle term I mean that which is predicated of both subjects;  by the extreme terms, the subjects of which the middle is predicated;  by the major term, that which comes next to the middle;  and by the minor that which is more distant from it.  The middle is placed outside the extreme terms, and is first by position.</p>

 

<p>(Aristotle, ''Prior Analytics'', 1.5).</p>

</blockquote>

</blockquote>

There is the Fact:

There is the Fact:

"All opossums are mammals." (O => M)

: "All opossums are mammals." (O => M)

There is the Rule:

There is the Rule:

"No newts are mammals." (N.M = 0)

: "No newts are mammals." (N.M = 0)

One deduces the Case:

One deduces the Case:

"No newts are opossums." (N.O = 0)

: "No newts are opossums." (N.O = 0)

The propositional content of this deduction is summarized on the right.  Expressed in terms of the corresponding classes, it says that if O c M and if N intersects M trivially, then N must also intersect O trivially.  Here, I use a raised dot "." to indicate either the conjunction of two propositions or the intersection of two classes, and I use a zero "0" to indicate either the identically false proposition or the empty class, leaving the choice of interpretation to the option of the reader.

The propositional content of this deduction is summarized on the right.  Expressed in terms of the corresponding classes, it says that if O c M and if N intersects M trivially, then N must also intersect O trivially.  Here, I use a raised dot "." to indicate either the conjunction of two propositions or the intersection of two classes, and I use a zero "0" to indicate either the identically false proposition or the empty class, leaving the choice of interpretation to the option of the reader.

The "third figure" of the syllogism is explained as follows:

The ''third figure'' of the syllogism is explained as follows:

<blockquote>

<blockquote>

If one of the terms applies to all and the other to none of the same subject, or if both terms apply to all or none of it, I call this kind of figure the Third;  and in it by the middle I mean that of which both the predications are made;  by extremes the predicates;  by the major term that which is [further from] the middle;  and by the minor that which is nearer to it.  The middle is placed outside the extremes, and is last by position. Aristotle, Prior Analytics, 1.6).

<p>If one of the terms applies to all and the other to none of the same subject, or if both terms apply to all or none of it, I call this kind of figure the Third;  and in it by the middle I mean that of which both the predications are made;  by extremes the predicates;  by the major term that which is [further from] the middle;  and by the minor that which is nearer to it.  The middle is placed outside the extremes, and is last by position.</p>

 

<p>(Aristotle, ''Prior Analytics'', 1.6).</p>

</blockquote>

</blockquote>

There is the Fact:

There is the Fact:

"All sonnets are poems." (S => P)

: "All sonnets are poems." (S => P)

There is the Case:

There is the Case:

"Some sonnets are rhapsodies." (S.R > 0)

: "Some sonnets are rhapsodies." (S.R > 0)

One deduces the Rule:

One deduces the Rule:

"Some rhapsodies are poems." (R.P > 0)

: "Some rhapsodies are poems." (R.P > 0)

The propositional content of this deduction is summarized on the right.  Expressed in terms of the corresponding classes, it says that if S c P and if R intersects S non-trivially then R must intersect P non-trivially.

The propositional content of this deduction is summarized on the right.  Expressed in terms of the corresponding classes, it says that if S c P and if R intersects S non-trivially then R must intersect P non-trivially.

=====1.4.3.2  Inductive Reasoning=====

=====1.4.3.2. Inductive Reasoning=====

(Aristotle, Prior Analytics, 2.23).

(Aristotle, ''Prior Analytics'', 2.23).

=====1.4.3.3  Abductive Reasoning=====

=====1.4.3.3. Abductive Reasoning=====

A choice of method cannot be justified by deduction or by induction, at least, not wholly, but involves an element of hypothesis.  In ancient times, this mode of inference to an explanatory hypothesis was described by the Greek word "apagoge", articulating an action or a process that "carries", "drives", or "leads" in a direction "away", "from", or "off".  This was later translated into the Latin "abductio", and that is the source of what is today called "abduction" or "abductive reasoning".  Another residue of this sense survives today in the terminology for "abductor muscles", those that "draw away (say, a limb or an eye) from a position near or parallel to the median axis of the body" (Webster's).

A choice of method cannot be justified by deduction or by induction, at least, not wholly, but involves an element of hypothesis.  In ancient times, this mode of inference to an explanatory hypothesis was described by the Greek word "apagoge", articulating an action or a process that "carries", "drives", or "leads" in a direction "away", "from", or "off".  This was later translated into the Latin "abductio", and that is the source of what is today called "abduction" or "abductive reasoning".  Another residue of this sense survives today in the terminology for "abductor muscles", those that "draw away (say, a limb or an eye) from a position near or parallel to the median axis of the body" (Webster's).

Suppose I have occasion to reason as follows:

Suppose I have occasion to reason as follows:

"It looks like a duck, so I guess it is a duck."

: "It looks like a duck, so I guess it is a duck."

Or even more simply:

Or even more simply:

"It looks blue, therefore it is blue."

: "It looks blue, therefore it is blue."

These are instances in which I am using abductive reasoning, according to the pattern of the following schema:

These are instances in which I am using abductive reasoning, according to the pattern of the following schema:

I observe a Fact:

I observe a Fact:

"It looks like X." (X')

: "It looks like X." (X')

I have in the back of my mind a general Rule:

I have in the back of my mind a general Rule:

"If it is X, then it looks like X." (X => X')

: "If it is X, then it looks like X." (X => X')

I reason my way back from the observed Fact and the assumed Rule to assert what I guess to be the Case:

I reason my way back from the observed Fact and the assumed Rule to assert what I guess to be the Case:

"It is X." (X)

: "It is X." (X)

The abduction is a hypothetical inference that results in a diagnostic conclusion, that is, a statement of opinion as to what is conjectured to be the case.  In each case the operation of abductive reasoning starts from a complex configuration, involving a number of explicit observations in the foreground and a class of implicit assumptions in the background, and it offers a provisional statement about certain possibility, one that is typically less conspicuous, obvious, or prominent, but still potentially present in the situation, and hopefully serving to explain the surprising or the problematic aspects of the whole state of affairs.

The abduction is a hypothetical inference that results in a diagnostic conclusion, that is, a statement of opinion as to what is conjectured to be the case.  In each case the operation of abductive reasoning starts from a complex configuration, involving a number of explicit observations in the foreground and a class of implicit assumptions in the background, and it offers a provisional statement about certain possibility, one that is typically less conspicuous, obvious, or prominent, but still potentially present in the situation, and hopefully serving to explain the surprising or the problematic aspects of the whole state of affairs.

But what if an example of a good method is already known to exist, one that has all of the commonly accepted properties that appear to define what a good method ought to be?  In this case, the abductive argument acquires the additional strength of an argument from analogy.

But what if an example of a good method is already known to exist, one that has all of the commonly accepted properties that appear to define what a good method ought to be?  In this case, the abductive argument acquires the additional strength of an argument from analogy.

=====1.4.3.4  Analogical Reasoning=====

=====1.4.3.4. Analogical Reasoning=====

The classical treatment of analogical reasoning by Aristotle explains it as a combination of induction and deduction.  More recently, C.S. Peirce gave two different ways of viewing the use of analogy, analyzing it into complex patterns of reasoning that involve all three types of inference.  In the appropriate place, it will be useful to consider these alternative accounts of analogy in detail.  At the present point, it is more useful to illustrate the different versions of analogical reasoning as they bear on the topic of choosing a method.

The classical treatment of analogical reasoning by Aristotle explains it as a combination of induction and deduction.  More recently, C.S. Peirce gave two different ways of viewing the use of analogy, analyzing it into complex patterns of reasoning that involve all three types of inference.  In the appropriate place, it will be useful to consider these alternative accounts of analogy in detail.  At the present point, it is more useful to illustrate the different versions of analogical reasoning as they bear on the topic of choosing a method.