But the case is different in philosophy where everyone believes that all is problematical, and few give themselves to the search after truth; and the greater number, in their desire to acquire a reputation for boldness of thought, arrogantly combat the most important of truths.

there will be none who dares to doubt the existence of God and the real and true distinction between the human soul and the body.

I shall show hereafter how from the fact that I know no other thing which pertains to my essence, it follows that there is no other thing which really does belong to it.

always depends either on the fact that we ascribe to God affections which are human, or that we attribute so much strength and wisdom to our minds that we even have the presumption to desire to determine and understand that which God can and ought to do.

But for those who, without caring to comprehend the order and connections of my reasonings, form their criticisms on detached portions arbitrarily selected, as is the custom with many, these, I say, will not obtain much profit from reading this Treatise. And although they perhaps in several parts find occasion of cavilling, they can for all their pains make no objection which is urgent or deserving of reply.

Now the first and principal matter which is requisite for thoroughly understanding the immortality of the soul is to form the clearest possible conception of it, and one which will be entirely distinct from all the conceptions which we may have of body;

we cannot conceive of Body excepting in so far as it is divisible, while the mind cannot be conceived of excepting as indivisible.

the human body, inasmuch as it differs from other bodies, is composed only of a certain configuration of members and of other similar accidents, while the human Mind is not similarly composed of any accidents, but is a pure substance.

the human body on the other hand becomes a different thing from the sole fact that the figure or form of any of its portions is found to be changed. From this it follows that the human body may indeed easily enough perish, but the mind [or soul of man (I make no distinction between them)] is owing to its nature immortal.

(But it must meanwhile be remarked that I do not in any way there treat of sin, that is to say of the error which is committed in the pursuit of good and evil, but only of that which arises in the deciding between the true and the false.

in considering these closely we come to see that they are neither so strong nor so evident as those arguments which lead us to the knowledge of our mind and of God; so that these last must be the most certain and most evident facts which can fall within the cognizance of the human mind.

I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences.

Now for this object it is not necessary that I should show that all of these are false, I shall perhaps never arrive at this end.

I ought no less carefully to withhold my assent from matters which are not entirely certain and indubitable than from those which appear to me manifestly to be false,

I shall only in the first place attack those principles upon which all my former opinions rested.

there is the fact that I am here, seated by the fire, attired in a dressing gown, having this paper in my hands and other similar matters.

in my dreams representing to myself the same things or sometimes even less probable things, than do those who are insane in their waking moments.

what happens in sleep does not appear so clear nor so distinct as does all this.

in dwelling carefully on this reflection I see so manifestly that there are no certain indications by which we may clearly distinguish wakefulness from sleep

let us reflect that possibly neither our hands nor our whole body are such as they appear to us to be.

painters, even when they study with the greatest skill to represent sirens and satyrs by forms the most strange and extraordinary, cannot give them natures which are entirely new, but merely make a certain medley of the members of different animals;

it is certain all the same that the colours of which this is composed are necessarily real.

there are at least some other objects yet more simple and more universal, which are real and true;

Arithmetic, Geometry and other sciences of that kind which only treat of things that are very simple and very general, without taking great trouble to ascertain whether they are actually existent or not, contain some measure of certainty and an element of the indubitable.

If, however, it is contrary to His goodness to have made me such that I constantly deceive myself, it would also appear to be contrary to His goodness to permit me to be sometimes deceived, and nevertheless I cannot doubt that He does permit this.

For these ancient and commonly held opinions still revert frequently to my mind, long and familiar custom having given them the right to occupy my mind against my inclination and rendered them almost masters of my belief; nor will I ever lose the habit of deferring to them or of placing my confidence in them, so long as I consider them as they really are, i.e. opinions in some measure doubtful, as I have just shown, and at the same time highly probable, so that there is much more reason to believe in than to deny them.

I allow myself to be deceived, and for a certain time pretend that all these opinions are entirely false and imaginary,

since I am not considering the question of action, but only of knowledge. I shall then suppose, not that God who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me;

I shall proceed by setting aside all that in which the least doubt could be supposed to exist, just as if I had discovered that it was absolutely false; and I shall ever follow in this road until I have met with something which is certain, or at least, if I can do nothing else, until I have learned for certain that there is nothing in the world that is certain.

But how can I know there is not something different from those things that I have just considered, of which one cannot have the slightest doubt?

But I have already denied that I had senses and body. Yet I hesitate, for what follows from that? Am I so dependent on body and senses that I cannot exist without these? But I was persuaded that there was nothing in all the world, that there was no heaven, no earth, that there were no minds, nor any bodies:

without doubt I exist also if he deceives me, and let him deceive me as much as he will, he can never cause me to be nothing so long as I think that I am something. So that after having reflected well and carefully examined all things, we must come to the definite conclusion that this proposition: I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive it.

I find here that thought is an attribute that belongs to me; it alone cannot be separated from me. I am, I exist, that is certain. But how often? Just when I think; for it might possibly be the case if I ceased entirely to think, that I should likewise cease altogether to exist.

But what then am I? A thing which thinks. What is a thing which thinks? It is a thing which doubts, understands, [conceives], affirms, denies, Wills, refuses, which also imagines and feels.

I cannot prevent myself from thinking, that corporeal things, whose images are framed by thought, which are tested by the senses, are much more distinctly known than that obscure part of me which does not come under the imagination.

my mind loves to wander, and cannot yet suffer itself to be retained within the just limits of truth.

What then did I know so distinctly in this piece of wax? It could certainly be nothing of all that the Senses brought to my notice, since all these things which fall under taste, smell, sight, touch, and hearing, are found to be changed, and yet the same wax remains.

simply a body which a little while before appeared tome as perceptible under these forms, and which is now perceptible under others.

this conception which I have of the wax is not brought about by the faculty of imagination.

I could not even understand through the imagination what this piece of wax is, and that it is my mind alone which perceives it.

solely by the faculty of judgment which rests in my mind, I comprehend that which I believed I saw with my eyes.

it is certain that although some error may still be found in my judgment, I can nevertheless not perceive it thus without a human mind.

do I not know myself, not only with much more truth and certainty, but also with much more distinctness and clearness?

it is now manifest to me that even bodies are not properly speaking known by the senses or by the faculty of imagination, but by the understanding only, and since they are not known from the fact that they are seen or touched, but only because they are understood, I see clearly that there is nothing which is easier for me to know than my mind.

I can establish as a general rule that all things which I perceive very clearly and very distinctly are true.

what did I clearly [and distinctly] perceive in them? Nothing more than that the ideas or thoughts of these things were presented to my mind.

But when I took anything very simple and easy in the sphere of arithmetic or geometry into consideration, e.g. that two and three together made five, and other things of the sort, were not these present to my mind so clearly as to enable me to affirm that they were true?

Of my thoughts some are, so to speak, images of the things, and to these alone is the title "idea" properly applied; examples are my thought of a man or of a chimera, of heaven, of an angel, or [even] of God.

yet by this action I always add something else to the idea which I have of that thing; and of the thoughts of this kind some are called volitions or affections, and others judgments.

they cannot properly speaking be false; for whether I imagine a goat or a chimera, it is not less true that I imagine the one that the other.

But the principal error and the commonest which we may meet with in them, consists in my judging that the ideas which are in me are similar or conformable to the things which are outside me;

But again I may possibly persuade myself that all these ideas are of the nature of those which I term adventitious, or else that they are all innate, or all fictitious: for I have not yet clearly discovered their true origin.

whether I will or whether I do not will, I feel heat, and thus I persuade myself that this feeling, or at least this idea of heat, is produced in me by something which is different from me,

For just as these impulses of which I have spoken are found in me, notwithstanding that they do not always concur with my will, so perhaps there is in me some faculty fitted to produce these ideas without the assistance of any external things, even though it is not yet known by me; just as, apparently, they have hitherto always been found in me during sleep without the aid of any external objects.

it is not a necessary consequence that they should resemble these.

These two ideas cannot, indeed, both resemble the same sun, and reason makes me believe that the one which seems to have originated directly from the sun itself, is the one which is most dissimilar to it. All this causes me to believe that until the present time it has not been by a judgment that was certain [or premeditated], but only by a sort of blind impulse that I believed that things existed outside of, and different from me, which, by the organs of my senses, or by some other method whatever it might be, conveyed these ideas or images to me [and imprinted on me their similitudes].

There is no doubt that those which represent to me substances are something more, and contain so to speak more objective reality within them [that is to say, by representation participate in a higher degree of being or perfection] than those that simply represent modes or accidents;

And from this it follows, not only that something cannot proceed from nothing, but likewise that what is more perfect, that is to say, which has more reality within itself, cannot proceed from the less perfect.

But in order that an idea should contain some one certain objective reality rather than another, it must without doubt derive it from some cause in which there is at least as much formal reality as this idea contains of objective reality.

although it may be the case that one idea gives birth to another idea, that cannot continue to be so indefinitely; for in the end we must reach an idea whose cause shall be so to speak an archetype,

the ideas in me are like [pictures or] images which can, in truth, easily fall short of the perfection of the objects from which they have been derived, but which can never contain anything greater or more perfect.

if the objective reality of any one of my ideas is of such a nature as clearly to make me recognise that it is not in me either formally or eminently, and that consequently I cannot myself be the cause of it, it follows of necessity that I am not alone in the world, but that there is another being which exists, or which is the cause of this idea.

As regards the ideas which represent to me other men or animals, or angels, I can however easily conceive that they might be formed by an admixture of the other ideas which I have of myself, of corporeal things, and of God, even although there were apart from me neither men nor animals, nor angels, in all the world. And in regard to the ideas of corporeal objects, I do not recognise in them anything so great or so excellent that they might not have possibly proceeded from myself;

it is only in judgments that falsity, properly speaking, or formal falsity, can be met with, a certain material falsity may nevertheless be found in ideas, i.e. when these ideas represent what is nothing as though it were something.

if it is correct to say that cold is merely a privation of heat, the idea which represents it to me as something real and positive will not be improperly termed false, and the same holds good of other similar ideas.

As to the clear and distinct idea which I have of corporeal things, some of them seem as though I might have derived them from the idea which I possess of myself, as those which I have of substance, duration, number, and such like.

But as to all the other qualities of which the ideas of corporeal things are composed, to wit, extension, figure, situation and motion, it is true that they are not formally in me, since I am only a thing that thinks; but because they are merely certain modes of Substance [and so to speak the vestments under which corporeal substance appears to us] and because I myself am also a substance, it would seem that they might be contained in me eminently.

By the name God I understand a substance that is infinite [eternal, immutable], independent, all-knowing, all-powerful, and by which I myself and everything else, if anything else does exist, have been created.

Nor should I imagine that I do not perceive the infinite by a true idea, but only by the negation of the finite, just as I perceive repose and darkness by the negation of movement and of light; for, on the contrary, I see that there is manifestly more reality in infinite substance than in finite, and therefore that in some way I have in me the notion of the infinite earlier then the finite, to wit, the notion of God before that of myself. For how would it be possible that I should know that I doubt and desire, that is to say, that something is lacking to me, and that I am not quite perfect, unless I had within me some idea of a Being more perfect than myself, in comparison with which I should recognise the deficiencies of my nature?

we cannot nevertheless imagine that His idea represents nothing real to me, as I have said of the idea of cold.

it is sufficient that I should understand this, and that I should judge that all things which I clearly perceive and in which I know that there is some perfection,

At the same time I recognise that this cannot be. For, in the first place, although it were true that every day my knowledge acquired new degrees of perfection, and that there were in my nature many things potentially which are not yet there actually, nevertheless these excellences do not pertain to [or make the smallest approach to] the idea which I have of God in whom there is nothing merely potential

I perceive that the objective being of an idea cannot be produced by a being that exists potentially only, which properly speaking is nothing, but only by a being which is formal or actual.

But [were I independent of every other and] were I myself the author of my being, I should doubt nothing and I should desire nothing, and finally no perfection would be lacking to me; for I should have bestowed on myself every perfection of which I possessed any idea and should thus be God.

from the fact that I was in existence a short time ago it does not follow that I must be in existence now, unless some cause at this instant, so to speak, produces me anew, that is to say, conserves me.

the distinction between creation and conservation is solely a distinction of the reason.

if such a power did reside in me, I should certainly be conscious of it. But I am conscious of nothing of the kind, and by this I know clearly that I depend on some being different from myself.

And it is perfectly manifest that in this there can be no regression into infinity, since what is in question is not so much the cause which formerly created me, as that which conserves me at the present time.

the unity, the simplicity or the inseparability of all things which are in god is one of the principal perfections which I conceive to be in Him.

so far as my parents [from whom it appears I have sprung] are concerned, although all that I have ever been able to believe of them were true, that does not make it follow that it is they who conserve me, nor are they even the authors of my being in any sense, in so far as I am a thinking being; since what they did was merely to implant certain dispositions

the only alternative is that it is innate in me, just as the idea of myself is innate in me.

For from the sole fact that God created me it is most probable that in some way he has placed his image and similitude upon me, and that I perceive this similitude (in which the idea of God is contained) by means of the same faculty by which I perceive myself,

From this it is manifest that He cannot be a deceiver, since the light of nature teaches us that fraud and deception necessarily proceed from some defect.