I. DO WE KNOW ANYTHING?

Answer, yes; we know ourselves. Should anyone say, I doubt this; I enquire, Do you know that you doubt it? Should he reply, I doubt that I doubt it; I enquire again, Do you know that you doubt that you doubt it? Should he reply, No, I do not know anything; I enquire again, Do you know that you do not know anything? Should he say, No, I only guess that I do not know anything; I enquire again, Do you know that you thus guess? Should he reply, It only seems as if I thus guess; I enquire, Do you know that so it seems? Should he reply, No, this seeming is nothing; I enquire again, Do you know that this seeming is nothing? Should he reply, No, but only so it seems; I reply, Then you are sure that so it seems; and if you are sure of this, or if you are sure that you are not sure of this, it amounts to the same thing. We know something -- we know ourselves; it is impossible to doubt this.

II. HOW DO WE KNOW OURSELVES?

I answer, in consciousness. That is, we are directly aware of ourselves in what we call consciousness. But what is consciousness? The word has been used ambiguously. Some times as the general faculty of knowledge; in this sense Sir William Hamilton often used it. Sometimes it is used as a function of the general faculty of knowledge, that function by which we know ourselves. Sometimes it is spoken of as self-knowledge. It is common to use the term as signifying either that particular function of the intellect by the use of which we know ourselves, or the knowledge of ourselves given by this function. More generally the term is used in this last sense, to signify self-knowledge; but often the faculty by which we obtain this knowledge is called by the same name by which we designate the knowledge itself. The connection in which the term is used will in general show the sense in which it is used. If we speak of the intuitions of consciousness, of course we speak of it as a function or faulty of self-knowledge; if we speak of self-knowledge as a consciousness, then it is plain that by consciousness we mean the knowledge of self.

I say then, IN CONSCIOUSNESS WE KNOW OURSELVES. Of this knowledge I remark:

1. That it is intuitive knowledge; that is, a knowledge obtained by a direct beholding of ourselves in the exercise of our various faculties.

2. I remark of this knowledge, or of consciousness, that it is a certain knowledge, knowledge of the highest possible kind, a knowledge that cannot be doubted. To call its validity in question is to question the validity of all knowledge, which we have seen, is nonsense.

III. WHAT DO WE KNOW OF OURSELVES IN CONSCIOUSNESS?

1. We know our existence. This is not an inference; "Cogito ergo sum," is a mere sophism. If I am not directly aware of my existence, how do I know that I think; and from the consciousness of mere thought, what right have I to infer that I think, or that I exist at all. There is no premise from which this can be inferred. The mere consciousness of thought affords not the least evidence that I am the thinking substance, or that I exist. And why should I say, I think? The very language implies that I know that I am, in knowing that I think. The very conception of thinking includes the assumption that I am. In consciousness, then, I know my own existence. (Cogito ergo sum, I think therefore I exist)

2. In consciousness I know that I have three distinct faculties: The faculty of knowledge; the faculty or susceptibility of feeling; the faculty or power of willing, choosing, acting. I know in the exercise of these different faculties or susceptibilities, that I posses them. I know, for instance, that I know; and in this knowledge I know that I am and that I have a faculty of knowledge, because I am conscious of using it. I know that I feel; and in the exercise of feeling I know that I possess the susceptibility or faculty of feeling. I know that I will, choose; and in willing and choosing I know that I possess and use the power or faculty of willing and choosing. This knowledge, this feeling, this willing, I know to be my own; and it is impossible for me to doubt either the exercise or the existence of the faculties thus exercised.

3. In consciousness I know all of myself that is knowable by me of myself.

4. In consciousness I know myself as distinct from that which is not myself; and in the very conception of myself as self I know that that exists which is not myself. Of this I am in some way as certain as that I exist myself. Indeed the conception of self implies the conception of not self. Self can be defined only as we discriminate between that which is self and that which is not self. I am, then, in consciousness directly aware of myself, which implies that I am also aware of that which is not myself.

Because of his peculiar definition of consciousness, Sir William Hamilton insists that this awareness of that which is not myself is strictly a consciousness. It is true that we are conscious of knowing that there is a not self; but is not this knowledge an intuition of the faculty of perception and distinct from consciousness but known in consciousness? It is sufficient to say that whether this as a knowledge of the not self, is a direct intuition of consciousness, or is an intuition of the perception faculty, which intuition is given to us in consciousness -- certain it is that we have this knowledge, which we can no more doubt than we can doubt the knowledge of ourselves.

5. In consciousness we know that the intellect has various functions; some of which are: Consciousness, sense, reason, conscience, memory, imagination, etc. Of consciousness I shall say no more at present, as it has been, for our present purpose sufficiently defined. Of sense, reason, and conscience, more things need in this place to be said.

IV. WHAT IS MEANT BY SENSE?

Sense is that function of the intellect by which we directly intuit the material world, including our own bodies and all material objects. It has been common to regard sense as that function of the intellect that intuits sensation. Sensation is an impression in the sensibility made either by some material object, or by some thought or action of the mind.

Sensation is a feeling. I once received the common idea that sense perception was merely a perception of the sensation, a feeling in the sensibility; but I do not now so regard it. Philosophers who have regarded sense as merely giving sensation have found it impossible to find any valid proof of the existence of an outward cause of sensation. They have said truly, that sensation being a feeling of the mind has in it none of the qualities that we attribute to bodies, and consequently that from the sensation we cannot infer the qualities of body or the existence of those outward things which we suppose have created the sensation.

This difficulty has stumbled many philosophers, and they have admitted that there was no valid reason for believing in the existence of the material universe. But other philosophers (as Sir William Hamilton) maintain that sense does not give us sensation, but that we are directly aware of sensation in consciousness -- that we are directly conscious of the feeling in the sensibility which we call sensation, and do not know it by a sense of perception. This class of philosophers maintain that by sense we directly perceive the primary qualities, at least, of material bodies.

The sensationalists object to this, that it is impossible to conceive how sense can directly perceive the qualities of external bodies. But to this it is justly replied, it is also impossible to conceive how sense could give us sensation.

We know not how it is that we are directly aware of ourselves, or how it is that we directly intuit anything in consciousness, sense, or reason. How an impression upon the sensibility should be irresistibly known to me, I cannot tell. The fact I know; the how I do not know. So it is with all our knowledge. Certain it is that we do not get the existence and qualities of external objects as an inference from sensation. We actually know that we do not thus get it -- that we have the knowledge not as an inference from premises. That we do not get it logically we know just as we know our existence.

For example, in knowing the material world around me I know that I do not get at it in this way: Phenomena imply substance; substance is as its phenomena are. Here are the phenomena; these phenomena imply substance, and this substance must be as the phenomena are; therefore such are the material substances around me. Now who is not aware in consciousness that this is not the way in which one gets a knowledge of his surroundings?

Who, for example, ever looked at an object and reasoned in that way, or could conceive himself as getting a knowledge of that object by such a process of reasoning? No, we are directly aware that we perceive it. Certain qualities of it are revealed to us irresistibly and directly. The object stands face to face with the perceptive faculty; and its primary qualities are as surely known to us as our own existence, and precisely in the same way, only through the use of another intuitive function of the intellect.

In consciousness I directly know my own existence; in consciousness I know also that I directly perceive the existence of other things. The faculty that directly perceives material objects I call sense. It would be out of place here to enter into an inquiry with regard to the particular attributes or qualities of the outward world that are given in sense. This inquiry is in place in a treatise in psychology, but it is unessential to our present course of study. For the present it is enough for us to know that by the function of sense we know with certainty the existence of the material universe.

Of this function, then, in conclusion, let me remark, first, that it is an intuitive function of the intellect, [and] gets all knowledges by a direct beholding. From the very nature of its perceptions, its testimony is to be received as valid. Nay, it is impossible to doubt the validity of its revelations. Let philosophers deny as they will the existence of the outward world; they know it still, and give as constant evidence to themselves and everybody else that they know it as other men do.

It should here be remarked that intuitive knowledge is always irresistible knowledge, by whatever function of the intellect the intuition is given. In intuitive knowledge the object known and the knowing faculty stand face to face. Such is the nature of the objects of intuitive knowledge, and such the nature of the faculty of intuition, that standing face to face we cannot help knowing these objects. They are directly beheld, and known with irresistible certainty.

It should also here be said, that in consciousness we are aware of sense perceptions and of all that passes within us; so that with whatever function of the intellect knowledge is obtained, in consciousness we have the report of all these knowledges. The same is true of our feeling, willing, imagining, remembering, dreaming, and whatever passes within us.