* W. J. Fox, Mon. Rep., p. 45: 1835.
** The reader will find that logician is need in the sense
of skilfulness in eliciting and exhibiting reality. By that
which I call logical is meant that which is truthful. I
presume that is the sense to which this high word should be
confined. It is the lax application of this term to mere
dexterity in evading the truth according to rule, that has
so increased the unsatisfactory race of professed sceptics.
—See Scepticism, chap. XII.
*** Langhornea' Preface to the Lives of Plutarch.
The general object of Lord Bacon's philosophy, writes Bruce, an Edinburgh professor of logic of the last century, is to connect the reasoning powers of man with experiments for the improvement of natural knowledge.
To create a just taste for philosophical investigation, required—
1. A display of the true, that they may be distinguished from the false subjects of inquiry.
2. Scientific rules to direct the discovery of the laws of nature.
But to 'display the true,' is to display the facts on which the truth rests. The 'discovery of the laws of nature' implies observation of the operations of nature. The philosophy of Bacon, says Macaulay, began in observation and ended in arts.
It is most obvious, as the reader will gather from what has been advanced, that for guarding, to the greatest possible extent, against error in conclusions, it is necessary to take into consideration the character of the data from which we reason—and to do this, we must draw from the general sources of knowledge to which the Logic of the Schools refers us. If we happen not to possess an accurate acquaintance with these branches, we must draw upon the best notions we have of them, or apply such natural sagacity as we happen to possess. But whether the information we happen to possess be complete or partial, it is not well that we are left to apply it at random, without any definite mode of procedure; and if logic refuses to assist us, and gives only a vague reference elsewhere, we must endeavour to assist ourselves. The datum of all arguments is a proposition, an assertion, or denial; and to ascertain its truth (upon which the value of the whole reasoning depends) we have to do with the facts upon which it rests, and the terms in which it is expressed. For it may be here observed, that the truth or falsity of every proposition depends upon facts. To ascertain the general accuracy of facts, we have to appeal to received standards of certainty; and to fix the meaning of terms, we have recourse to a plain principle of definition. In the task of recognising truth, so necessary in examining the premises of an argument, one is wonderfully assisted by being familiarised with the sources of truth, and the mode of its discovery. In these operations the tutored and untutored may alike be assisted by simple general rules. If these rules prove not infallible in every case, they will prove successful in the majority of cases.
Since general rules are the only, rules that the vast field of facts admits of, they are not to be rejected on light grounds. They enable us to set forth intelligibly the reasons of our own conviction, and to detect and expose the fundamental fallacies of apparent arguments. Since they direct us where the Logic of the Schools leaves us without a guide, their value is apparent.
The logical management of the syllogism involves much abstruseness respecting 'genus' and 'species,' the 'quantity' and 'quality' of 'propositions', 'contraries,' 'sub-contraries,' 'contradictions,' and 'subalterns.' Stepping by 'illative conversion,' 'six rules to be observed with respect to categorical syllogism' next demand attention, followed hard by eleven moods which can be used in a legitimate syllogism, Viz.——A, A, A, A, A, I, A., E, E, A, E, O, A, I, I, A, O, O, E, A, E, E, A, O, E, I, O, I, A, I, O, A, O.' In the middle of this abstract train march the 'undistributed middle' and the 'illicit process,' attended by four figures represented by the following mnemonic lines, which must be carefully committed to memory:'—
Fig. 1. bArbArA, cElArEnt, dArII, fErIOque prioris.
Fig. 2. cEsArE, dAmEstrEs, fEstInO, bArOkO,* secundæ.
Fig. 3. tertia, dArAptI, dIsAmIs, dAtIsI, fElAptOn, bOkArdO,** fErlsO, habet; quarta insuper addit.
Fig. 4. brAmAntIp, cAmEnEs, dImArIs, fEsApo, frEsIsOn.
A motley group, too numerous to be particularised, bring up the complex rear of 'Modals,' 'Hypotheticals,' 'Conditionals,' and 'Disjunctives.' This is certainly not the portal through which the populace can at present pass to logic, even if such logic helped them to all truth, and saved them from all fallacy.
But this species of logic is not without interest. Symbolic letters and mnemonic lines are not without attractions to those who understand them. There is poetry in an algebraic sign, when it is the emblem of a difficulty solved, and a wonderful result simply arrived at. To try the whole power of words, and discover every form of language in which a legitimate deduction can be expressed, is no ignoble task. It is a high discipline, but it belongs rather to the age of leisure than this of 'copperasfames, cotton-fuz, gin-riot, wrath, and toil'—to the luxuries rather than the utilities of learning.
There is the inefficiency of the syllogism, and also the vitiation produced by its employment.
1. It corrupts the taste for philosophical invention by placing philosophy in abstractions, and withdrawing it from the observation of nature.
2. It creates a reliance on principles, which originate in the hypotheses of philosophers, not in the laws of nature.
3. It makes truth the result of the forms of argument, not of scientific evidence.***
* Or, Fakoro, as indeed all the particulars in this place
recited.
** Or, Dokamo. but a brief summary of the subjects
comprised in his logic in reference to the syllogism.
***Bruce. These references to Fakoro and Dokamo are Whately's.
Lord Kames cites from the father of logic the following syllogism, which will bear repetition as an extraordinary instance of that assumption for which the Logic of the Schools provides no remedy:—
Heavy bodies naturally tend to the centre of the universe.
We know, by experience, that heavy bodies tend to the centre of the earth.
Therefore the centre of the earth is the centre of the universe.
But by what experience did Aristotle discover the centre of the universe, so as to become aware that heavy bodies naturally tend there? On what facts rest the measurement of the radii from our earth to the boundless circumference of space? How did he ascertain the limits of that which has no limits? Yet, strange to say, the Logic of the Schools prides itself in leaving us where the Stagyrite left us.
'When mankind began to reason on the phenomena of nature, they were solicitous to abstract, and they formed general propositions from a limited observation. Though these propositions were assumed, they were admitted as true. They were not examined by appeals to nature, but by comparison with other propositions.'*
In this syllogism from Aristotle,
