whose thoughts follow the turn that Kant has given modern thinking to appreciate the defects of Leibniz than to realize his greatness. I have endeavored, therefore, in the body of the work, to identify my thought with that of Leibniz as much as possible, to assume his standpoint and method, and, for the most part, to confine express criticism upon his limitations to the final chapter. In particular, I have attempted to bring out the relations of philosophy to the growing science of his times, to state the doctrine of pre-established harmony as he himself meant it, and to give something like consistency and coherency to his doctrine of material existence and of nature. This last task seemed especially to require doing. I have also endeavored to keep in mind, throughout, Leibniz’s relations to Locke, and to show the “Nouveaux Essais” as typical of the distinction between characteristic British and German thought.
JOHN DEWEY.
May, 1888.
Chapter I.
The Man.
“He who knows me only by my writings does not know me,” said Leibniz. These words—true, indeed, of every writer, but true of Leibniz in a way which gives a peculiar interest and charm to his life—must be our excuse for prefacing what is to be said of his “New Essays concerning the Human Understanding” with a brief biographical sketch.
Gottfried Wilhelm Leibniz was born in Leipzig June 21, 1646. His father, who died when Leibniz was only six years old, was a professor in the university and a notary of considerable practice. From him the future philosopher seems to have derived his extraordinary industry and love of detail. Such accounts as we have of him show no traces of the wonderful intellectual genius of his son, but only a diligent, plodding, faithful, and religious man, a thoroughly conscientious husband, jurist, and professor. Nor in the lines of physical heredity can we account for the unique career of Leibniz by his mother’s endowments. The fact, however, that she was patient in all trial, living in peace with her neighbors, anxious for unity and concord with all people, even with those not well disposed to her, throws great light upon the fundamental trait of Leibniz’s ethical nature. As in so many cases, it is the inherited moral characteristics which form the basis of the intellectual nature. The love of unity which was a moral trait in Leibniz’s mother became in him the hunger for a harmonious and unified mental world; the father’s devotion to detail showed itself as the desire for knowledge as minute and comprehensive as it was inter-related.
Left without his father, he was by the advice of a discerning friend allowed free access to the library. Leibniz never ceased to count this one of the greatest fortunes of his life. Writing in after years to a friend, he says:—
“When I lost my father, and was left without any direction in my studies, I had the luck to get at books in all languages, of all religions, upon all sciences, and to read them without any regular order, just as my own impulse led me. From this I obtained the great advantage that I was freed from ordinary prejudices, and introduced to many things of which I should otherwise never have thought.”
In a philosophical essay, in which he describes himself under the name of Gulielmus Pacidius, he says:—
“Wilhelm Friedlieb, a German by birth, who lost his father in his early years, was led to study through the innate tendency of his spirit; and the freedom with which he moved about in the sciences was equal to this innate impulse. He buried himself, a boy eight years old, in a library, staying there sometimes whole days, and, hardly stammering Latin, he took up every book which pleased his eyes. Opening and shutting them without any choice, he sipped now here, now there, lost himself in one, skipped over another, as the clearness of expression or of content attracted him. He seemed to be directed by the Tolle et lege of a higher voice. As good fortune would have it, he gave himself up to the ancients, in whom he at first understood nothing, by degrees a little, finally all that was really necessary, until he assumed not only a certain coloring of their expression, but also of their thought,—just as those who go about in the sun, even while they are occupied with other things, get sun-browned.”
And he goes on to tell us that their influence always remained with him. Their human, their important, their comprehensive ideas, grasping the whole of life in one image, together with their clear, natural, and transparent mode of expression, adapted precisely to their thoughts, seemed to him to be in the greatest contrast with the writings of moderns, without definiteness or order in expression, and without vitality or purpose in thought,—“written as if for another world.” Thus Leibniz learned two of the great lessons of his life,—to seek always for clearness of diction and for pertinence and purpose of ideas.
Historians and poets first occupied him; but when in his school-life, a lad of twelve or thirteen years, he came to the study of logic, he was greatly struck, he says, by the “ordering and analysis of thoughts which he found there.” He gave himself up to making tables of categories and predicaments, analyzing each book that he read into suitable topics, and arranging these into classes and sub-classes. We can imagine the astonishment of his playmates as he burst upon them with a demand to classify this or that idea, to find its appropriate predicament. Thus he was led naturally to the philosophic books in his father’s library,—to Plato and to Aristotle, to the Scholastics. Suarez, in particular, among the latter, he read; and traces of his influences are to be found in the formulation of his own philosophic system. At about this same time he took great delight in the theological works with which his father’s library abounded, reading with equal ease and pleasure the writings of the Lutherans and of the Reformed Church, of the Jesuits and the Jansenists, of the Thomists and the Arminians. The result was, he tells us, that he was strengthened in the Lutheran faith of his family, but, as we may easily imagine from his after life, made tolerant of all forms of faith.
In 1661 the boy Leibniz, fifteen years old, entered the University of Leipzig. If we glance back upon his attainments, we find him thoroughly at home in Latin, having made good progress in Greek, acquainted with the historians and poets of antiquity, acquainted with the contemporary range of science, except in mathematics and physics, deeply read and interested in ancient and scholastic philosophy and in the current theological discussions. Of himself he says:—
“Two things were of extraordinary aid to me: in the first place, I was self-taught; and in the second, as soon as I entered upon any science I sought for something new, even though I did not as yet thoroughly understand the old. I thus gained two things: I did not fill my mind with things empty and to be unlearned afterwards,—things resting upon the assertion of the teacher, and not upon reason; and secondly, I never rested till I got down to the very roots of the science and reached its principles.”
While there is always a temptation to force the facts which we know of a man’s early life, so as to make them seem to account for what appears in mature years, and to find symbolisms and analogies which do not exist, we are not going astray, I think, if we see foreshadowed in this early education of Leibniz the two leading traits of his later thought,—universality and individuality. The range of Leibniz’s investigations already marks him as one who will be content with no fundamental principle which does not mirror the universe. The freedom with which he carried them on is testimony to the fact that even at this age the idea of self-development, of individual growth from within, was working upon him. In the fact, also, that he was self-taught we find doubtless the reason that he alone of the thinkers of this period did not have to retrace his steps, to take a hostile attitude towards the ideas into which he was educated, and to start anew upon a foundation then first built. The development of the thought of Leibniz is so gradual, continuous, and constant that it may serve as a model of the law by which the “monad” acts. Is not his early acquaintance with ancient literature and mediæval philosophy the reason that he could afterwards write that his philosophical system “connects Plato with Democritus,
