Syllogistic Reasoning (Modern Enthymeme)


Kristen Seas ENGL 624/Sullivan Fall 2005 Purdue University	Syllogistic Reasoning: Argument is, more specifically, the expression in language of reasoning, whose underlying form is universally syllogistic even if the argument is not fully expressed as a syllogism. I draw on Whately primarily here, whose philosophy of logic articulates the key premises underlying the 19th century treatises that define enthymeme as the formal expression of a syllogism. I begin with Whately's foundational argument, in his Elements of Logic, that reasoning operates the same universally, as captured in the following definitions of logic: "For Logic, which is, as it were, the Grammar of Reasoning, does not bring forward the regular Syllogism as a distinct mode of argumentation, designed to be substituted for any other mode; but as the form to which all correct reasoning may be ultimately reduced […]." (12) "[Others] have in short considered Logic as an art of reasoning; whereas (so far as it is an art) it is the art of reasoning; the logician's object being, not to lay down principles by which one may reason, but, by which all must reason, even though they are not distinctly aware of them" (25). "In pursuing the supposed investigation, it will be found that every Conclusion is deduced, in reality, from two other propositions" (26). "An argument thus stated regularly and at full length, is called a Syllogism; which therefore is evidently not a peculiar kind of argument, but only a peculiar form of expression, in which every argument may be stated." (26-7) "[…] a Syllogism must be 'an argument so expressed, that the conclusiveness of it is manifest from the mere force of the expression,' i.e. without considering the meaning of the terms […]" (79) - Richard Whately, 1844 [1826] Locke and Campbell (among others) , however, contest the universality of syllogistic reasoning, which may have some bearing on the appreciation of the enthymeme as a truncated syllogism. "And I readily own, that all right reasoning may be reduced to [Aristotle's] forms of syllogism. But yet I think, without any diminution to him, I may truly say, that they are not the only nor the best way of reasoning, for the leading of those into truth who are willing to find it, and desire to make the best use they may of their reason, for the attainment of knowledge." (Bk IV, Ch XVII, §4) "But in neither case is it syllogism that discovered these ideas, or showed the connexion of them; for they must be both found out, and the connexion everywhere perceived, before they can rationally be made us of in syllogism." (Bk IV, Ch XVII, §4) "Reason, by its own penetration, where it is strong and exercised, usually sees quicker and clearer without syllogism." (Bk IV, Ch XVII, §4) - John Locke, 1690 "It is long since I was first convinced, by what Mr. Locke had said on the subject, that the syllogistic art, with its figures and moods, serves more to display the ingenuity of the inventor, and to exercise the address and fluency of the learner, than to assist the diligent inquirer in his researches after truth. The method of proving by syllogism, appears, even on a superficial review, both unnatural and prolix." (198) "[T]he proper province of the syllogistical sciene is rather the adjustment of our language, in expressing ourselves on subjects previously known, than the acquisition of knowledge in things themselves." (202) "If you regard only the thing signified, the argument conveys no instruction, not does it forward us in the knowledge of things a single step. But if you regard principally the signs, it may serve to correct misapplications." (202) - George Campbell, 1776 Whately openly criticizes these two thinkers for their dismissal of syllogistic reasoning, a critique primarily in his assertion that many philosophers have ignored that expression in language is essential to reasoning, as well as the tendency to conflate Reasoning with the scientific study of Nature. As he writes in his Elements of Logic: "I believe that in respect to the present subject, the view I am alluding to arise in great measure from men's not perceiving that Language, of some kind or other, is (as will be more fully shown hereafter) an indispensable instrument of all Reasoning that properly deserves the name." (11) Logic is "'the Art of employing language properly for the purpose of Reaosning; and of distinguishing what is properly and truly an Argument, from spurious imitations of it." (57). "[Locke] had no clearer notions than they [previous logicians], of the just limits of logical science, as confined to the theory of Reasoning; and of the distinct character of that operation from the observations and experiments which are essential to the study of Nature." (9) "Dr. Campbell endeavours, under this misapprehension, with some ingenuity, and not without an air of plausibility, to show that every syllogism must be futile and worthless, because the Premises virtually assert the Conclusion: little dreaming, of course, that his objections, however specious, lie against the process of reasoning itself, universally; and will, therefore, of course, apply to those very arguments which he is himself adducing." (36)
Table of Contents: Project Description 19th c. Logical Definitions of Enthymeme Main Contentions of Project: Thought v. Language Logic v. Rhetoric Argument and Reason Syllogistic Reasoning Enthymeme as Abridged Argument Lost Translation - Missing Definition of Enthymeme Works Cited

Kristen Seas
ENGL 624/Sullivan
Fall 2005
Purdue University

Syllogistic Reasoning:

Argument is, more specifically, the expression in language of reasoning, whose underlying form is universally syllogistic even if the argument is not fully expressed as a syllogism.

I draw on Whately primarily here, whose philosophy of logic articulates the key premises underlying the 19th century treatises that define enthymeme as the formal expression of a syllogism. I begin with Whately's foundational argument, in his Elements of Logic, that reasoning operates the same universally, as captured in the following definitions of logic:

"For Logic, which is, as it were, the Grammar of Reasoning, does not bring forward the regular Syllogism as a distinct mode of argumentation, designed to be substituted for any other mode; but as the form to which all correct reasoning may be ultimately reduced […]." (12)

"[Others] have in short considered Logic as an art of reasoning; whereas (so far as it is an art) it is the art of reasoning; the logician's object being, not to lay down principles by which one may reason, but, by which all must reason, even though they are not distinctly aware of them" (25).

"In pursuing the supposed investigation, it will be found that every Conclusion is deduced, in reality, from two other propositions" (26).

"An argument thus stated regularly and at full length, is called a Syllogism; which therefore is evidently not a peculiar kind of argument, but only a peculiar form of expression, in which every argument may be stated." (26-7)

"[…] a Syllogism must be 'an argument so expressed, that the conclusiveness of it is manifest from the mere force of the expression,' i.e. without considering the meaning of the terms […]" (79)

- Richard Whately, 1844 [1826]

Locke and Campbell (among others) , however, contest the universality of syllogistic reasoning, which may have some bearing on the appreciation of the enthymeme as a truncated syllogism.

"And I readily own, that all right reasoning may be reduced to [Aristotle's] forms of syllogism. But yet I think, without any diminution to him, I may truly say, that they are not the only nor the best way of reasoning, for the leading of those into truth who are willing to find it, and desire to make the best use they may of their reason, for the attainment of knowledge." (Bk IV, Ch XVII, §4)

"But in neither case is it syllogism that discovered these ideas, or showed the connexion of them; for they must be both found out, and the connexion everywhere perceived, before they can rationally be made us of in syllogism." (Bk IV, Ch XVII, §4)

"Reason, by its own penetration, where it is strong and exercised, usually sees quicker and clearer without syllogism." (Bk IV, Ch XVII, §4)

- John Locke, 1690

"It is long since I was first convinced, by what Mr. Locke had said on the subject, that the syllogistic art, with its figures and moods, serves more to display the ingenuity of the inventor, and to exercise the address and fluency of the learner, than to assist the diligent inquirer in his researches after truth. The method of proving by syllogism, appears, even on a superficial review, both unnatural and prolix." (198)

"[T]he proper province of the syllogistical sciene is rather the adjustment of our language, in expressing ourselves on subjects previously known, than the acquisition of knowledge in things themselves." (202)

"If you regard only the thing signified, the argument conveys no instruction, not does it forward us in the knowledge of things a single step. But if you regard principally the signs, it may serve to correct misapplications." (202)

- George Campbell, 1776

Whately openly criticizes these two thinkers for their dismissal of syllogistic reasoning, a critique primarily in his assertion that many philosophers have ignored that expression in language is essential to reasoning, as well as the tendency to conflate Reasoning with the scientific study of Nature. As he writes in his Elements of Logic:

"I believe that in respect to the present subject, the view I am alluding to arise in great measure from men's not perceiving that Language, of some kind or other, is (as will be more fully shown hereafter) an indispensable instrument of all Reasoning that properly deserves the name." (11)

Logic is "'the Art of employing language properly for the purpose of Reaosning; and of distinguishing what is properly and truly an Argument, from spurious imitations of it." (57).

"[Locke] had no clearer notions than they [previous logicians], of the just limits of logical science, as confined to the theory of Reasoning; and of the distinct character of that operation from the observations and experiments which are essential to the study of Nature." (9)

"Dr. Campbell endeavours, under this misapprehension, with some ingenuity, and not without an air of plausibility, to show that every syllogism must be futile and worthless, because the Premises virtually assert the Conclusion: little dreaming, of course, that his objections, however specious, lie against the process of reasoning itself, universally; and will, therefore, of course, apply to those very arguments which he is himself adducing." (36)

Syllogistic Reasoning:

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