[137] THE biographical sketch here announced, has more than an ordinary claim to the attention of the reader. The subject of it is a philosopher, who, beside the peculiarities incident to genius, had several that belonged exclusively to himself. These he was careful to study and explain; and the notes which he has left behind him, seem to entitle him to the rare eulogy, of having given an accurate and candid delineation of his own character. His biographer, too, had the advantage of being intimately acquainted with the person whom he has undertaken to describe, and has been attentive to mark whatever appeared singular in the constitution or progress of his mind.
George Lewis Le Sage was born at Geneva in 1724, to which city his father, a native of France, had for some time retired, and lived by giving private lessons in mathematics and natural philosophy. The son was early initiated in these studies receiving, at the same time, in all the branches of literature, as liberal a course of education as his father's limited income would allow. A marked opposition, however, in their tastes and intellectual propensities, prevented the son from reaping from his father's instructions all the advantage that might have been expected. The old man was well informed; but his knowledge was very much confined to facts, and was accompanied with little tendency to reason, or to generalize. His son, again, even when a boy, delighted in connecting his ideas by general and abstract principles, and was not more inquisitive about facts, than about the relations in which they stood to one another. This propensity arose, in some measure at least, from the weakness of his memory, which forced him to study the most just and constant connexions among things, in order to prevent both words and ideas from escaping his recollection entirely. 'It was thus,' says M. Prevost, 'that we saw him, in his maturer years, and particularly in his old age, avoiding, with the greatest care, whatever could trouble the order of his thoughts, and substituting, with much art, a logical series of mental operations to the effort which the recollection of a single unconnected fact would necessarily have cost him'.
The history of Le Sage does indeed illustrate, in the dearest manner, the relation between the faculties of memory and abstraction, and the power which each has to supply the deficiencies [138] of the other. Generalization gives us a command over our ideas more complete than we can ever derive from the mere efforts of memory: It holds in its hand the clue by which this latter faculty must be guided through the labyrinth of things; and there is room to doubt, whether the power thus given to the mind is not the main source of the delight arising from abstract and philosophic speculation. Were the memory in itself to become so perfect, as to be independent of connecting principles, generalization would not be necessary, and perhaps would rarely be attempted. Two minds, both disposed to the acquisition of knowledge, could hardly be constituted with less conformity to one another, than those of Le Sage and his son. When the young man was labouring to classify his ideas, and to reduce them under general heads, the father was perpetually starting objections to his rules, and bringing forward the instances most difficult to be reduced to any general principle of arrangement. This seemed to proceed, not from any desire to embarrass or distress his son, but from a dislike which he had conceived (singular, doubtless, in a mathematician) to general methods, and to all systems whatsoever. The education, therefore, which he gave his son, was truly antiphilosophic, and certainly had no tendency to produce that love of order, system and method which characterized him through his whole life. But the mind may be constituted with some powers so weak, that discipline cannot improve them; and with others so strong, that discipline, when most perverse, cannot destroy them. Nothing could give to young Le Sage a memory nearly equal to that of ordinary men; and nothing could take from him a delight and skill in generalization, which were vastly superior.