THE ELEMENTS OF LOGIC K. 1. INTRODUCTION. Importance of the Know ledge of our felves. F all the human Sciences, that concerning Man, is certainly the moft worthy of Man, and the moft neceffary Part of Knowledge. We find ourselves in this World furrounded with a Variety of Objects; we have Powers and Faculties fitted to deal with them, and are happy or miferable in proportion as we know how to frame a right Judgment of Things, and fhape our Actions agreeably to the Circumstances in which we are placed. No Study therefore is more important than that which introduces us to the Knowledge of ourfelves. Hereby we become acquainted with the Extent and Capacity of the human Mind, and learning to diftinguish what Objects it is fuited to, and in what manner it must proceed, in order to compa's its Ends, we arrive by degrees at that Juftnefs and Truth of Understanding, which is the great Perfection of a rational Being. Different Gradations of II. IF we look attentively into Things, and furvey them in their full Extent, we fee them rifing one above another in various Degrees of Eminence. Among the inanimate Parts of Matter fome exhibit nothing worthy our Attention, their Parts feem as it were jumbled together by mere Chances VOL. II. B Things. nor nor can we difcover any Beauty, Order, or Regularity in their Compofition. In others we difcern the finest Arrangement, and a certain Elegance of Contexture, that makes us affix to them a Notion of Worth and Excellence. Thus Metals, and precious Stones, are conceived as far furpaffing thofe unformed Maffes of Earth, that lie every where expofed to view. If we trace Nature onward, and purfue her through the vegetable and animal Kingdoms, we find her ftill multiplying her Perfections, and rifing by a just Gradation, from mere Mechanism to Perception, and from Perception in all its various Degrees, to Reafon and Understanding. III. BUT though Reafon be the Boundary, by Usefulness of Culture, and which Man is diftinguifhed from the other Creaparticularly tures that furround him, yet we are far from of the Study finding it the fame in all. Nor is this Inequality of Logick. to be wholly afcribed to the original Make of Men's Minds, or the Difference of their natural Endowments. For if we look abroad into the feveral Nations of the World, fome are over-run with Ignorance and Barbarity, others flourish in Learning and the Sciences; and what is yet more remarkable, the fame People have, in different Ages, been diftinguished by thefe very oppofite Characters. It is therefore by Culture, and a due Application of the Powers of our Minds, that we increase their Capacity, and carry human Reason to Perfection. Where this Method is followed, Knowledge and Strength of Understanding never fail to enfue; where it is neglected, we remain ignorant of our own Worth and thofe latent Qualities of the Soul, by which fhe is fitted to furvey this vaft Fabrick of the World, to scan the Heavens, and fearch into the Caufes of Things, lie buried in Darkness and Obfcurity. No Part of Knowledge therefore yields a fairer Profpcct of Improvement, than that which takes account of the Understanding, examines its Powers and Faculties, and fhews the Ways by which it comes to attain its various Notions of Things. This is properly the Defign of Logick, which may be justly ftiled the Hiftory of the human Mind, inafmuch as it traces the Progrefs of our Knowledge, from our first and fimple Perceptions, through all their different Combinations, and all thofe numerous Deductions that refult from variously comparing them one with another. It is thus that we are let into the natural Frame and Contexture of our own Minds, and learn in what manner we ought to conduct our Thoughts, in order to arrive at Truth, and avoid Error. We fee how to build one Discovery upon another, and by preferving the Chain of Rea Reafonings uniform and unbroken, to pursue the Relations of Things through all their Labyrinths and Windings, and at length exhibit them to the View of the Soul, with all the Advantages of Light and Conviction. IV. BUT as the Understanding in advancing from one Part of Knowledge to another, proceeds the Mind. Operations of by a juft Gradation, and exerts various Acts, according to the different Progrefs it has made, Logicians have been careful to note these several Steps, and have diftinguished them in their Writings by the Name of the Operations of the Mind. Thefe they make four in Number, and agreeably to that, have divided the whole Syftem of Logick into four Parts, in which thefe Acts are feverally explained, and the Conduct and Procedure of the Mind, in its different Stages of Improvement, regulated by proper Rules and Obfervations. Now, in order to judge how far Logicians have followed Nature, in this Diftinction of the Power of the Understanding, let us take a fhort View of the Mind, and the manner of its Progrefs, according to the Experience we have of it in ourselves, and fee whither the Chain of our own Thoughts will without Conftraint lead us. Perception. V. FIRST then, we find ourselves furrounded with a Variety of Objects, which acting differently upon our Senfes, convey diftinct Impreffions into the Mind, and thereby rouse the Attention and Notice of the Understanding. By reflecting too on what paffes within us, we become fenfible of the Operations of our own Minds, and attend to them as a new Set of Impreffions. But in all this there is only bare Consciousness. The Mind, without proceeding any farther, takes notice of the Impreffions that are made upon it, and views Things in order, as they prefent themselves one after another. This Attention of the Understanding to the Object acting upon it, whereby it becomes fenfible of the Impreffions they make, is called by Logicians Perception; and the Notices themfelves, as they exift in the Mind, and are there treasured up to be the Materials of Thinking and Knowledge, are diftinguished by the Name of Ideas. VI. BUT the Mind does not always reft fatiffied in the bare View and Contemplation of its Judgment. Ideas. It is of a more active and bufy Nature, and likes to be affembling them together, and comparing them one with another. In this complicated View of Things, it readily difcerns, that fome agree, and others difagree, and joins or feparates them according to this Perception. Thus upon com B 2 paring paring the Idea of two added to two, with the Idea of four, we at firft Glance perceive their Agreement, and there upon pronounce that two and two are equal to four. Again, that white is not black, that five is less than feven, are Truths to which we immediately affent, as foon as we compare thofe Ideas together. This is the firft and fimpleft Act of the Mind, in determining the Relations of Things, when by a bare Attention to its own Ideas, comparing any two of them together, it can at once fee how far they are connected or disjoined. The Knowledge thence derived is called intuitive, as requiring no Pains or Examination; and the Act of the Mind affembling its Ideas together, and joining or disjoining them according to the Refult of its Perceptions, is what Logicians term Judgment. VII. INTUITION affords the highest degree of Reafening. Certainty, it breaks in with an irrefiftible Light upon the Understanding, and leaves no room for Doubt or Hefitation. Could we in all Cafes, by thus putting two Ideas together, difcern immediately their Agreement or Difagreement, we fhould be exempt from Error, and all its fatal Confequences. But it fo happens, that many of our Ideas are of fuch a Nature, that they cannot be thus examined in Concert, or by any immediate Application one to another; and then it becomes neceffary to find out fome other Ideas, that will admit of this Application, that by means of them we may discover the Agreement or Difagreement we search for. Thus the Mind wanting to know the Agreement or Difagreement in Extent, between two inclofed Fields, which it cannot fo put together, as to difcover their Equality or Inequality, by an immediate Comparifon, cafts about for fome intermediate Idea, which by being applied first to the one, and then to the other, will difcover the Relation it is in queft of. Accordingly it affumes fome ftated Length, as a Yard, &c. and meaturing the Fields, one after the other, comes by that means to the Knowledge of the Agreement or Difagreement in queftion. The intervening Ideas, made ufe of on thefe Occafions, are called Proofs; and the Exercife of the Mind in finding them out, and applying them for the Discovery of the Truths it is in search of, is what we term Reafoning. And here let it be obferved, that the Knowledge gained by Reasoning, is a Deduction from our intuitive Perceptions, and ultimately founded on them. Thus in the Cafe before-mentioned, having found by measuring, that one of the Fields makes threefcore fquare Yards, and the other only fifty-five, we thence conclude |