Elements of Algebra

XX EULER. motive, his Treatise had the advantage of being composed under an immediate experience of the method best adapted to the natural progress of a learner's ideas: from the want of which, men of the most profound knowledge are often awkward and unsatisfactory, when they attempt elementary instruction. It is not improbable, that we may be farther indebted to the circumstance of our Author's blindness; for the loss of this sense is generally succeeded by the improvement of other faculties. As the surviving organs, in particular, acquire a degree of sensibility, which they did not previously possess; so the most charming visions of poetical fancy have been the offspring of minds, on which external scenes had long been closed. And perhaps a philosopher, familiarly acquainted with Euler's writings, might trace some improvement in perspicuity of method, and in the flowing progress of his deductions, after this calamity had befallen him; which, leaving "an universal blank of nature's works," favors that entire seclusion of the mind, which concentrates attention, and gives liveliness and vigor to the conceptions. In men devoted to study, we are not to look for those strong, complicated passions, which are contracted amidst the vicissitudes and tumult of public life. To delineate the character of Euler, requires no contrasts of coloring. Sweetness of disposition, moderation in the passions, and simplicity of manners, were his leading features. Susceptible of the domestic affections, he was open to all their amiable