PREFACE. IT has been frequently objected to metaphysical speculations, that they subserve no useful purpose; and it must be allowed, that there are many inquiries in this department of intellectual exertion, which lead, in appearance, and even in reality, to no practical result. This is however a defect inherent in every pursuit, and can be brought as no specific objection against the philosophy of mind. many substances are analyzed by the chemist, which can never be rendered useful; how many plants are minutely described by the naturalist, which might have remained in obscurity without the least possible detriment to How the world; and how many events are narrated by the historian, from which no beneficial inference can be drawn! It seems to be a necessary condition of human science, that we should learn many useless things, in order to become acquainted with those which are of service; and as it is impossible, antecedently to experience, to know the value of our acquisitions, the only way in which mankind can secure all the advantages of knowledge is to prosecute their inquiries in every possible direction. There can be no greater impediment to the progress of science than a perpetual and anxious reference at every step to palpable utility. Assured that the general result will be beneficial, it is not wise to be too solicitous as to the immediate value of every individual ef fort. Besides, there is a certain completeness to be attained in every science, for which we are obliged to acquire many particulars not otherwise of any worth. Nor is it to be forgotten, that trivial and apparently useless acquisitions are often the necessary preparatives to important discoveries. The labours of the antiquary, the verbal critic, the collator of mouldering manuscripts, the describer of microscopic objects (labours which may appear to many out of all proportion to the value of the result), may be preparing the way for the achievements of some splendid genius, who may combine their minute details into a magnificent system, or evolve from a multitude of particulars, collected with painful toil, some general principle destined to illuminate the career of future ages. To no one perhaps are the labours of his predecessors, even when they are apparently trifling or unsuccessful, of more service than to the metaphysician; and he who is well acquainted with the science can scarcely fail to perceive, that many of its inquiries are gradually converging to important results. Unallied as they may appear to present utility, it is not hazarding much to assert, that the world must hereafter be indebted to them for the extirpation of many mischievous errors, and the correction of a great part of those loose and illogical opinions by which society is now pervaded. The principal Essays in the following work are attempts to throw the light of metaphysical investigation on subjects intimately connected with the affairs and the happiness of mankind. The importance of the topics discussed in the two Essays to which the volume owes its title will be acknowledged by all, and it will be perceived by the attentive inquirer, that the principles which the author has there attempted to establish lead to the most momentous conclusions, many of which he has contented himself with leaving to the sagacity of his readers. |