[72] (1) In order to pursue our investigation, let us confront ourselves with some true idea, whose object we know for certain to be dependent on our power of thinking, and to have nothing corresponding to it in nature. (2) With an idea of this kind before us, we shall, as appears from what has just been said, be more easily able to carry on the research we have in view.
(72:3) For instance, in order to form the conception of a sphere, I invent a cause at my pleasure - namely, a semicircle revolving round its center, and thus producing a sphere. (4) This is indisputably a true idea; and, although we know that no sphere in nature has ever actually been so formed, the perception remains true, and is the easiest manner of conceiving a sphere.
(72:5) We must observe that this perception a.s.serts the rotation of a semicircle - which a.s.sertion would be false, if it were not a.s.sociated with the conception of a sphere, or of a cause determining a motion of the kind, or absolutely, if the a.s.sertion were isolated. (6) The mind would then only tend to the affirmation of the sole motion of a semicircle, which is not contained in the conception of a semicircle, and does not arise from the conception of any cause capable of producing such motion.
(72:7) Thus falsity consists only in this, that something is affirmed of a thing, which is not contained in the conception we have formed of that thing, as motion or rest of a semicircle.
(8) Whence it follows that simple ideas cannot be other than true - e.g., the simple idea of a semicircle, of motion, of rest, of quant.i.ty, &c.
(72:9) Whatsoever affirmation such ideas contain is equal to the concept formed, and does not extend further. (10) Wherefore we form as many simple ideas as we please, without any fear of error.
[73] (1) It only remains for us to inquire by what power our mind can form true ideas, and how far such power extends. (2) It is certain that such power cannot extend itself infinitely. (3) For when we affirm somewhat of a thing, which is not contained in the concept we have formed of that thing, such an affirmation shows a defect of our perception, or that we have formed fragmentary or mutilated ideas. (4) Thus we have seen that the notion of a semicircle is false when it is isolated in the mind, but true when it is a.s.sociated with the concept of a sphere, or of some cause determining such a motion. (73:5) But if it be the nature of a thinking being, as seems, prima facie, to be the case, to form true or adequate thoughts, it is plain that inadequate ideas arise in us only because we are parts of a thinking being, whose thoughts - some in their entirety, others in fragments only - const.i.tute our mind.
[74] (1) But there is another point to be considered, which was not worth raising in the case of fiction, but which give rise to complete deception - namely, that certain things presented to the imagination also exist in the understanding - in other words, are conceived clearly and distinctly. (2) Hence, so long as we do not separate that which is distinct from that which is confused, certainty, or the true idea, becomes mixed with indistinct ideas. (3) For instance, certain Stoics heard, perhaps, the term "soul," and also that the soul is immortal, yet imagined it only confusedly; they imaged, also, and understood that very subtle bodies penetrate all others, and are penetrated by none. (74:4) By combining these ideas, and being at the same time certain of the truth of the axiom, they forthwith became convinced that the mind consists of very subtle bodies; that these very subtle bodies cannot be divided &c.
[75] (1) But we are freed from mistakes of this kind, so long as we endeavor to examine all our perceptions by the standard of the given true idea. (2) We must take care, as has been said, to separate such perceptions from all those which arise from hearsay or uncla.s.sified experience. (3) Moreover, such mistakes arise from things being conceived too much in the abstract; for it is sufficiently self-evident that what I conceive as in its true object I cannot apply to anything else. (75:4) Lastly, they arise from a want of understanding of the primary elements of nature as a whole; whence we proceed without due order, and confound nature with abstract rules, which, although they be true enough in their sphere, yet, when misapplied, confound themselves, and pervert the order of nature. (5) However, if we proceed with as little abstraction as possible, and begin from primary elements - that is, from the source and origin of nature, as far back as we can reach, - we need not fear any deceptions of this kind.
[76] (1) As far as the knowledge of the origin of nature is concerned, there is no danger of our confounding it with abstractions. (2) For when a thing is conceived in the abstract, as are all universal notions, the said universal notions are always more extensive in the mind than the number of individuals forming their contents really existing in nature. (3) Again, there are many things in nature, the difference between which is so slight as to be hardly perceptible to the understanding; so that it may readily happen that such things are confounded together, if they be conceived abstractedly. (4) But since the first principle of nature cannot (as we shall see hereafter) be conceived abstractedly or universally, and cannot extend further in the understanding than it does in reality, and has no likeness to mutable things, no confusion need be feared in respect to the idea of it, provided (as before shown) that we possess a standard of truth.
(5) This is, in fact, a being single and infinite [76z] ; in other words, it is the sum total of being, beyond which there is no being found. [76a]
[77] (1) Thus far we have treated of the false idea. We have now to investigate the doubtful idea - that is, to inquire what can cause us to doubt, and how doubt may be removed. (2) I speak of real doubt existing in the mind, not of such doubt as we see exemplified when a man says that he doubts, though his mind does not really hesitate. (77:3) The cure of the latter does not fall within the province of method, it belongs rather to inquiries concerning obstinacy and its cure.
[78] (1) Real doubt is never produced in the mind by the thing doubted of. (2) In other words, if there were only one idea in the mind, whether that idea were true or false, there would be no doubt or certainty present, only a certain sensation. (3) For an idea is in itself nothing else than a certain sensation. (4) But doubt will arise through another idea, not clear and distinct enough for us to be able to draw any certain conclusions with regard to the matter under consideration; that is, the idea which causes us to doubt is not clear and distinct. (5) To take an example.
(78:6) Supposing that a man has never reflected, taught by experience or by any other means, that our senses sometimes deceive us, he will never doubt whether the sun be greater or less than it appears.
(7) Thus rustics are generally astonished when they hear that the sun is much larger than the earth. (8) But from reflection on the deceitfulness of the senses [78a] doubt arises, and if, after doubting, we acquire a true knowledge of the senses, and how things at a distance are represented through their instrumentality, doubt is again removed.
[79] (1) Hence we cannot cast doubt on true ideas by the supposition that there is a deceitful Deity, who leads us astray even in what is most certain. (2) We can only hold such an hypothesis so long as we have no clear and distinct idea - in other words, until we reflect the knowledge which we have of the first principle of all things, and find that which teaches us that G.o.d is not a deceiver, and until we know this with the same certainty as we know from reflecting on the are equal to two right angles. (3) But if we have a knowledge of G.o.d equal to that which we have of a triangle, all doubt is removed.
(79:4) In the same way as we can arrive at the said knowledge of a triangle, though not absolutely sure that there is not some arch-deceiver leading us astray, so can we come to a like knowledge of G.o.d under the like condition, and when we have attained to it, it is sufficient, as I said before, to remove every doubt which we can possess concerning clear and distinct ideas.
[80] (1) Thus, if a man proceeded with our investigations in due order, inquiring first into those things which should first be inquired into, never pa.s.sing over a link in the chain of a.s.sociation, and with knowledge how to define his questions before seeking to answer them, he will never have any ideas save such as are very certain, or, in other words, clear and distinct; for doubt is only a suspension of the spirit concerning some affirmation or negation which it would p.r.o.nounce upon unhesitatingly if it were not in ignorance of something, without which the knowledge of the matter in hand must needs be imperfect. (2) We may, therefore, conclude that doubt always proceeds from want of due order in investigation.
[81] (1) These are the points I promised to discuss in the first part of my treatise on method. (2) However, in order not to omit anything which can conduce to the knowledge of the understanding and its faculties, I will add a few words on the subject of memory and forgetfulness.
(81:3) The point most worthy of attention is, that memory is strengthened both with and without the aid of the understanding.
(4) For the more intelligible a thing is, the more easily is it remembered, and the less intelligible it is, the more easily do we forget it. (5) For instance, a number of unconnected words is much more difficult to remember than the same number in the form of a narration.
[82] (1) The memory is also strengthened without the aid of the understanding by means of the power wherewith the imagination or the sense called common, is affected by some particular physical object. (2) I say particular, for the imagination is only affected by particular objects. (3) If we read, for instance, a single romantic comedy, we shall remember it very well, so long as we do not read many others of the same kind, for it will reign alone in the memory (4) If, however, we read several others of the same kind, we shall think of them altogether, and easily confuse one with another.
(82:5) I say also, physical. (6) For the imagination is only affected by physical objects. (7) As, then, the memory is strengthened both with and without the aid of the understanding, we may conclude that it is different from the understanding, and that in the latter considered in itself there is neither memory nor forgetfulness.
[83] (1) What, then, is memory? (2) It is nothing else than the actual sensation of impressions on the brain, accompanied with the thought of a definite duration, [83d] of the sensation. (3) This is also shown by reminiscence. (4) For then we think of the sensation, but without the notion of continuous duration; thus the idea of that sensation is not the actual duration of the sensation or actual memory. (83:5) Whether ideas are or are not subject to corruption will be seen in philosophy. (6) If this seems too absurd to anyone, it will be sufficient for our purpose, if he reflect on the fact that a thing is more easily remembered in proportion to its singularity, as appears from the example of the comedy just cited. (83:7) Further, a thing is remembered more easily in proportion to its intelligibility; therefore we cannot help remember that which is extremely singular and sufficiently intelligible.
[84] (1) Thus, then, we have distinguished between a true idea and other perceptions, and shown that ideas fict.i.tious, false, and the rest, originate in the imagination - that is, in certain sensations fortuitous (so to speak) and disconnected, arising not from the power of the mind, but from external causes, according as the body, sleeping or waking, receives various motions.
(2) But one may take any view one likes of the imagination so long as one acknowledges that it is different from the understanding, and that the soul is pa.s.sive with regard to it. (3) The view taken is immaterial, if we know that the imagination is something indefinite, with regard to which the soul is pa.s.sive, and that we can by some means or other free ourselves therefrom with the help of the understanding. (4) Let no one then be astonished that before proving the existence of body, and other necessary things, I speak of imagination of body, and of its composition. (5) The view taken is, I repeat, immaterial, so long as we know that imagination is something indefinite, &c.
[85] (1) As regards as a true idea, we have shown that it is simple or compounded of simple ideas; that it shows how and why something is or has been made; and that its subjective effects in the soul correspond to the actual reality of its object. (2) This conclusion is identical with the saying of the ancients, that true proceeds from cause to effect; though the ancients, so far as I know, never formed the conception put forward here that the soul acts according to fixed laws, and is as it were an immaterial automaton.
[86] (1) Hence, as far as is possible at the outset, we have acquired a knowledge of our understanding, and such a standard of a true idea that we need no longer fear confounding truth with falsehood and fiction. (2) Neither shall we wonder why we understand some things which in nowise fall within the scope of the imagination, while other things are in the imagination but wholly opposed to the understanding, or others, again, which agree therewith. (3) We now know that the operations, whereby the effects of imagination are produced, take place under other laws quite different from the laws of the understanding, and that the mind is entirely pa.s.sive with regard to them.
[87] (1) Whence we may also see how easily men may fall into grave errors through not distinguishing accurately between the imagination and the understanding; such as believing that extension must be localized, that it must be finite, that its parts are really distinct one from the other, that it is the primary and single foundation of all things, that it occupies more s.p.a.ce at one time than at another and other similar doctrines, all entirely opposed to truth, as we shall duly show.
[88] (1) Again, since words are a part of the imagination - that is, since we form many conceptions in accordance with confused arrangements of words in the memory, dependent on particular bodily conditions, - there is no doubt that words may, equally with the imagination, be the cause of many and great errors, unless we strictly on our guard.
[89] (1) Moreover, words are formed according to popular fancy and intelligence, and are, therefore, signs of things as existing in the imagination, not as existing in the understanding. (2) This is evident from the fact that to all such things as exist only in the understanding, not in the imagination, negative names are often given, such as incorporeal, infinite, &c. (3) So, also, many conceptions really affirmative are expressed negatively, and vice versa, such as uncreate, independent, infinite, immortal, &c., inasmuch as their contraries are much more easily imagined, and, therefore, occurred first to men, and usurped positive names.
(89:4) Many things we affirm and deny, because the nature of words allows us to do so, though the nature of things does not. (5) While we remain unaware of this fact, we may easily mistake falsehood for truth.
[90] (1) Let us also beware of another great cause of confusion, which prevents the understanding from reflecting on itself.
(2) Sometimes, while making no distinction between the imagination and the intellect, we think that what we more readily imagine is clearer to us; and also we think that what we imagine we understand.
(3) Thus, we put first that which should be last: the true order of progression is reversed, and no legitimate conclusion is drawn.
[91] [91e] (1) Now, in order at length to pa.s.s on to the second part of this method, I shall first set forth the object aimed at, and next the means for its attainment. (2) The object aimed at is the acquisition of clear and distinct ideas, such as are produced by the pure intellect, and not by chance physical motions.
(3) In order that all ideas may be reduced to unity, we shall endeavor so to a.s.sociate and arrange them that our mind may, as far as possible, reflect subjectively the reality of nature, both as a whole and as parts.
[92] (1) As for the first point, it is necessary (as we have said) for our purpose that everything should be conceived, either solely through its essence, or through its proximate cause. (2) If the thing be self-existent, or, as is commonly said, the cause of itself, it must be understood through its essence only; if it be not self-existent, but requires a cause for its existence, it must be understood through its proximate cause. (3) For, in reality, the knowledge, [92f] of an effect is nothing else than the acquisition of more perfect knowledge of its cause.
[93] (1) Therefore, we may never, while we are concerned with inquiries into actual things, draw any conclusion from abstractions; we shall be extremely careful not to confound that which is only in the understanding with that which is in the thing itself. (2) The best basis for drawing a conclusion will be either some particular affirmative essence, or a true and legitimate definition. (93:3) For the understanding cannot descend from universal axioms by themselves to particular things, since axioms are of infinite extent, and do not determine the understanding to contemplate one particular thing more than another.
[94] (1) Thus the true method of discovery is to form thoughts from some given definition. (2) This process will be the more fruitful and easy in proportion as the thing given be better defined. (3) Wherefore, the cardinal point of all this second part of method consists in the knowledge of the conditions of good definition, and the means of finding them. (4) I will first treat of the conditions of definition.
[95] (1) A definition, if it is to be called perfect, must explain the inmost essence of a thing, and must take care not to subst.i.tute for this any of its properties. (2) In order to ill.u.s.trate my meaning, without taking an example which would seem to show a desire to expose other people"s errors, I will choose the case of something abstract, the definition of which is of little moment. (95:3) Such is a circle. (4) If a circle be defined as a figure, such that all straight lines drawn from the center to the circ.u.mference are equal, every one can see that such a definition does not in the least explain the essence of a circle, but solely one of its properties. (5) Though, as I have said, this is of no importance in the case of figures and other abstractions, it is of great importance in the case of physical beings and realities: for the properties of things are not understood so long as their essences are unknown. (6) If the latter be pa.s.sed over, there is necessarily a perversion of the succession of ideas which should reflect the succession of nature, and we go far astray from our object.
[96] In order to be free from this fault, the following rules should be observed in definition:- I. (1) If the thing in question be created, the definition must (as we have said) comprehend the proximate cause.
(2) For instance, a circle should, according to this rule, be defined as follows: the figure described by any line whereof one end is fixed and the other free. (3) This definition clearly comprehends the proximate cause.
II. (4) A conception or definition of a thing should be such that all the properties of that thing, in so far as it is considered by itself, and not in conjunction with other things, can be deduced from it, as may be seen in the definition given of a circle: for from that it clearly follows that all straight lines drawn from the center to the circ.u.mference are equal. (5) That this is a necessary characteristic of a definition is so clear to anyone, who reflects on the matter, that there is no need to spend time in proving it, or in showing that, owing to this second condition, every definition should be affirmative. (6) I speak of intellectual affirmation, giving little thought to verbal affirmations which, owing to the poverty of language, must sometimes, perhaps, be expressed negatively, though the idea contained is affirmative.
[97] The rules for the definition of an uncreated thing are as follows:-- I. The exclusion of all idea of cause - that is, the thing must not need explanation by Anything outside itself.
II. When the definition of the thing has been given, there must be no room for doubt as to whether the thing exists or not.
III. It must contain, as far as the mind is concerned, no substantives which could be put into an adjectival form; in other words, the object defined must not be explained through abstractions.
IV. Lastly, though this is not absolutely necessary, it should be possible to deduce from the definition all the properties of the thing defined.
All these rules become obvious to anyone giving strict attention to the matter.
[98] (1) I have also stated that the best basis for drawing a conclusion is a particular affirmative essence. (2) The more specialized the idea is, the more it is distinct, and therefore clear. (3) Wherefore a knowledge of particular things should be sought for as diligently as possible.
[99] (1) As regards the order of our perceptions, and the manner in which they should be arranged and united, it is necessary that, as soon as is possible and rational, we should inquire whether there be any being (and, if so, what being), that is the cause of all things, so that its essence, represented in thought, may be the cause of all our ideas, and then our mind will to the utmost possible extent reflect nature. (2) For it will possess, subjectively, nature"s essence, order, and union. (3) Thus we can see that it is before all things necessary for us to deduce all our ideas from physical things - that is, from real ent.i.ties, proceeding, as far as may be, according to the series of causes, from one real ent.i.ty to another real ent.i.ty, never pa.s.sing to universals and abstractions, either for the purpose of deducing some real ent.i.ty from them, or deducing them from some real ent.i.ty. (4) Either of these processes interrupts the true progress of the understanding.
[100] (1) But it must be observed that, by the series of causes and real ent.i.ties, I do not here mean the series of particular and mutable things, but only the series of fixed and eternal things. (2) It would be impossible for human infirmity to follow up the series of particular mutable things, both on account their mult.i.tude, surpa.s.sing all calculation, and on account of the infinitely diverse circ.u.mstances surrounding one and the same thing, any one of which may be the cause of its existence or non-existence. (3) Indeed, their existence has no connection with their essence, or (as we have said already) is not an eternal truth.
[101] (1) Neither is there any need that we should understand their series, for the essences of particular mutable things are not to be gathered from their series or order of existence, which would furnish us with nothing beyond their extrinsic denominations, their relations, or, at most, their circ.u.mstances, all of which are very different from their inmost essence.
(101:2) This inmost essence must be sought solely from fixed and eternal things, and from the laws, inscribed (so to speak) in those things as in their true codes, according to which all particular things take place and are arranged; nay, these mutable particular things depend so intimately and essentially (so to phrase it) upon the fixed things, that they cannot either be conceived without them.
[102] (1) But, though this be so, there seems to be no small difficulty in arriving at the knowledge of these particular things, for to conceive them all at once would far surpa.s.s the powers of the human understanding. (2) The arrangement whereby one thing is understood, before another, as we have stated, should not be sought from their series of existence, nor from eternal things. (3) For the latter are all by nature simultaneous. (4) Other aids are therefore needed besides those employed for understanding eternal things and their laws. (5) However, this is not the place to recount such aids, nor is there any need to do so, until we have acquired a sufficient knowledge of eternal things and their infallible laws, and until the nature of our senses has become plain to us.
[103] (1) Before betaking ourselves to seek knowledge of particular things, it will be seasonable to speak of such aids, as all tend to teach us the mode of employing our senses, and to make certain experiments under fixed rules and arrangements which may suffice to determine the object of our inquiry, so that we may therefrom infer what laws of eternal things it has been produced under, and may gain an insight into its inmost nature, as I will duly show. (2) Here, to return to my purpose, I will only endeavor to set forth what seems necessary for enabling us to attain to knowledge of eternal things, and to define them under the conditions laid down above.
[104] (1) With this end, we must bear in mind what has already been stated, namely, that when the mind devotes itself to any thought, so as to examine it, and to deduce therefrom in due order all the legitimate conclusions possible, any falsehood which may lurk in the thought will be detected; but if the thought be true, the mind will readily proceed without interruption to deduce truths from it.
(104:2) This, I say, is necessary for our purpose, for our thoughts may be brought to a close by the absence of a foundation.
[105] (1) If, therefore, we wish to investigate the first thing of all, it will be necessary to supply some foundation which may direct our thoughts thither. (2) Further, since method is reflective knowledge, the foundation which must direct our thoughts can be nothing else than the knowledge of that which const.i.tutes the reality of truth, and the knowledge of the understanding, its properties, and powers. (3) When this has been acquired we shall possess a foundation wherefrom we can deduce our thoughts, and a path whereby the intellect, according to its capacity, may attain the knowledge of eternal things, allowance being made for the extent of the intellectual powers.
[106] (1) If, as I stated in the first part, it belongs to the nature of thought to form true ideas, we must here inquire what is meant by the faculties and power of the understanding. (2) The chief part of our method is to understand as well as possible the powers of the intellect, and its nature; we are, therefore, compelled (by the considerations advanced in the second part of the method) necessarily to draw these conclusions from the definition itself of thought and understanding.
[107] (1) But, so far as we have not got any rules for finding definitions, and, as we cannot set forth such rules without a previous knowledge of nature, that is without a definition of the understanding and its power, it follows either that the definition of the understanding must be clear in itself, or that we can understand nothing. (2) Nevertheless this definition is not absolutely clear in itself; however, since its properties, like all things that we possess through the understanding, cannot be known clearly and distinctly, unless its nature be known previously, understanding makes itself manifest, if we pay attention to its properties, which we know clearly and distinctly. (3) Let us, then, enumerate here the properties of the understanding, let us examine them, and begin by discussing the instruments for research which we find innate in us. See [31]
[108] (1) The properties of the understanding which I have chiefly remarked, and which I clearly understand, are the following:- I. (2) It involves certainty - in other words, it knows that a thing exists in reality as it is reflected subjectively.