Doubtless it would have been considered a very unimportant question two hundred years ago, as to whether heat were an igneous fluid or a mode of motion. Perhaps not more than two or three men wrestled with the question for centuries before it was settled. By the masses of the people they were regarded as wasting their time in vain and idle speculation. By an experiment made by Count Rumford, it was put beyond the possibility of doubt that heat was not an igneous fluid, but a mode of motion. Was this a question that concerned the multitudes, that two or three men spent a hundred years talking about and torturing their brains to understand? There is not a single human being in the civilized world to-day whose interests and welfare have not been touched by the settlement of it. There are millions of peasants in Russia who never heard of Count Rumford, or of an igneous fluid, or of caloric, who have this present year been fed by flour sent them by the western millers and transported on the strength of the conclusion that heat is not an igneous fluid, but a mode of motion. Every steam-car that crosses the continent, and every steamboat that crosses the ocean, moves in the wake of this same conclusion. At first we see some algebraic formulas, an array of curves and figures, that practical people said had nothing to do with everyday life. After a while we see the abstract conclusions reached by aid of the algebraic signs, and settled by the test of experiment, translated into steam engines, and transporting even the peasants of India and Mexico from one end of the country to the other. We see the abstract conclusions of the few thinkers turned into steam to spin the people’s clothes and grind the people’s bread.
In 1632 there was born at Wrington, Somersetshire, England, a boy, who was educated at the University of Oxford. In the esteem of his contemporaries he devoted his time to the consideration of subjects of no practical value. In the course of events he put the results of his study into a book known as “The Essay on the Human Understanding.” Few people read it. But the few who did read it started the ideas of it to circulating. They were translated into French and Latin, and were soon potent influences in the intellectual life of Europe. Were they practical and did they concern the ordinary affairs of men? They created the Encyclopedists of France. These learned men were the authors of the radical opinions which cut the people from the moorings of traditional and age-long thought. The fire and the blood of the Revolution were the legitimate expressions of the speculative essay of John Locke that not one in ten thousand ever read. The persons whose heads were cut off in the Reign of Terror must have thought the ideas exceedingly practical that led to the destruction of social and political institutions, that took form in a movement which respected neither law nor property nor life. The speculative opinions of John Locke not only helped to create the French Revolution, but they led to the idealism of Bishop Berkeley, and this in turn to the skeptical philosophy of David Hume. The modern successors of Hume are John Stuart Mill, Herbert Spencer, Leslie Stephen, Frederic Harrison, and Professor Huxley, whose contributions have been given to the popular reviews, and which have been read by all intelligent people. Every man in Europe and America has been influenced both in conduct and character by the speculative “Essay on the Human Understanding.”
Locke’s speculative philosophy passed through Berkeley to Hume, and through Hume reached Kant, the great German thinker, and resulted in the “Critique of Pure Reason.” This led to Fichte and Schelling, and finally to Hegel. This led to Heidelberg and the Tübingen school, to Bauer and Dewette, to extreme idealism and rationalism, translated into books and reviews and newspapers, and read by all the people, affecting their thought and life.
Even people who never read, who never open a book or a newspaper, have been influenced by the subtle piece of speculative reasoning given to the world by the great sensational philosopher of England. The spirit of utilitarianism and secularism prevalent throughout the world at the present time is easily traceable to it.
IV.
Before we can possibly know that truth is the provision for the intellectual nature of man, we must determine whether the knowing faculties, which he finds himself to possess, are capable of grasping truth and turning it into knowledge. The fight of skepticism in modern times has been made upon the knowing faculties. It is useless to talk about the existence of God, the inspiration of the Scriptures, the divinity of Christ, or the immortality of the soul, if the human intellect is, by its limitations, denied the possibility of knowing anything whatsoever concerning these things. It is a waste of time for me to attempt to dip water out of the ocean with a bucket with no bottom to it. What is the relation of the intelligence to the outer world? Does the outside world create knowledge in the mind by the impressions it makes upon it, or does the mind bring something to the outside world which converts this raw material into knowledge? Is knowledge a reflection of the outer, or a creation of the inner? Does nature work it in us, or is there some spontaneous, creative, organizing, mental activity within us that takes the material presented by nature, turning it into a rational system of knowledge? What is the relation between the being that knows and the object known? How much of the creative factor of knowledge does nature supply? How much does man supply? Can a man with deranged faculties get order out of a rational world? Can a man of sane mind get order out of an irrational world? If there is to be a rational system of knowledge built up in the mind, must there not be reason in the thinker and reason in the outside world, coming into organic relations, the one with the other? As to how we regard this question will determine how we regard truth, and whether or not it is possible for us to know it.
V.
The human mind has never been able to resist the conviction that there is such a thing as truth. Though baffled and defeated a thousand times, in every age, in its attempt to formulate truth, it has never been able to consent to give up the search for it. Interest in truth has kept alive and fostered the belief that the mind has power to understand it. The mind’s passion for truth has deepened its confidence in the faculties with which it is ever trying to discover it. The everlasting longing to know truth has been taken as implicit capacity to find it. Philosophic systems have been only so many devices and creations of the mind with which to take hold of truth. The methods proposed, in the first stages of philosophic thinking, for getting at the truth were crude, as the first instruments devised for cultivating the soil and getting out of it what there was in it for food, were crude. Thales, Pythagoras, and Anaximander first attempted to penetrate objective reality, to know its cause, to bring its multiplicity to unity, and to reduce its variety to law. The ever-changing phenomena by which they were surrounded necessarily eluded the meager theories with which they attempted to reduce them to order. They prepared the way, however, for systems which accommodated a greater number of facts. They made possible Plato and Aristotle, who, with hypotheses more complicated and more consonant with the reality they sought to grasp, found truth enough to keep the human race thinking for two thousand years. The blocks of truth they quarried from the mines of objective reality were used to carry up the theological and speculative temples of the Middle Ages.
After the failure of scholasticism, which denotes a period in human thought rather than a particular system of philosophy, Lord Bacon proposed the method of material induction to bring the mind into relations of knowledge with truth. He emphasized the study of the outward facts, their classification and organization. In his esteem, truth was to be reached by the consideration of actual, tangible things. Man was the interpreter of nature, and not necessarily its interpretation.