On the influence of signs in mathematical reasoning / by Charles Babbage.

  • Charles Babbage
Date:
1826
Catalogue details

Licence: Public Domain Mark

Credit: On the influence of signs in mathematical reasoning / by Charles Babbage. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The advantage of selecting in our signs, those which have some resemblance to, or which from some circumstance are as- sociated in the mind with the thing signified, has scarcely been stated with sufficient force: the fatigue, from which such an ar- rangement saves the reader, is very advantageous to the more com- plete devotion of his attention to the subject examined; and the more complicated the subject, the more numerous the symbols and the less their arrangement is susceptible of symmetry, the more indispensible will such a system be found. This rule is by no means confined to the choice of the letters which represent quantity, but is meant to extend, when it is possible, to cases where new arbitrary signs are invented to denote operations. In the formation of some of the most common algebraic signs, this maxim has been attended to ; but although in many individual instances it has been admitted, it is still desirable that it should be recognised as a general principle. The sign of equality was obviously adopted from the circumstance of the same relation existing between its two parts, as that which it indicates between the two quantities which it separates, and the propriety of this selection has confirmed its use, although Girard employed = to denote difference, and Descartes used »= to represent equality. In the two signs representing greater and less than a > b and h < a *, the prevalence of the same motive of choice is equally apparent, for it is immediately seen, that these signs are so contrived, that the largest end is always placed next to the largest quantity, and * That this principle operated in inducing Harriot, who first used these signs, to adopt them, I have now very little doubt: I may however, remark, that on my first initiation into Algebra, finding some difficulty in remembering their distinction, I formed the association above alluded to as a kind of artificial memory, a purpose, which it effectually answered.
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