220 THE GROUNDWORK OF SCIENCE

am intellectually, as it were, entirely at sea, drifting I know

not where or how. The idea that I can be really certain

about anything is for me an absurdity. What can I ascer-

tain about the cause and origin of the faculties I possess ?

For all I can tell I may be the sport of a demon who

amuses himself with deceiving me in all things " !

But to such a man we would say, why do you feel this

distrust of your faculties? It is evident that your want of

certainty about them can only be due to your certainty about

something else.

You -are convinced you cannot surely arrive at truth

because your faculties may be deceptive ; but on what is

this conviction of yours founded ? Why cannot you trust

them all the same? It is, and must be, owing to your

perception that no one can arrive at conclusions which are

themselves certain by means of premisses which are false, or

even uncertain. Now, in this perception of yours you are

evidently quite right, but please observe that you cannot

have the conviction you say you have about it except by

trusting your faculties after all. Therefore, if you are con-

vinced, as you say you are, about this impossibility of

attaining conclusions which are certain from false or

uncertain premisses, you must be convinced that your

faculties are not always fallacious, and you must also per-

ceive that your imaginary demon cannot deceive you in

everything.

Therefore, doubt as we may, certainty is the inalienable

possession of even the most absolute sceptic, who, when he

says he is certain of nothing even of his own scepticism

simply contradicts himself, and says what is mere nonsense.

At the outset of this our most important inquiry, namely,

the study of our highest faculties, it is necessary for the

reader thus to see clearly that certainty exists, and that he

not only can but must possess it a'bout some things, or

am intellectually, as it were, entirely at sea, drifting I know

not where or how. The idea that I can be really certain

about anything is for me an absurdity. What can I ascer-

tain about the cause and origin of the faculties I possess ?

For all I can tell I may be the sport of a demon who

amuses himself with deceiving me in all things " !

But to such a man we would say, why do you feel this

distrust of your faculties? It is evident that your want of

certainty about them can only be due to your certainty about

something else.

You -are convinced you cannot surely arrive at truth

because your faculties may be deceptive ; but on what is

this conviction of yours founded ? Why cannot you trust

them all the same? It is, and must be, owing to your

perception that no one can arrive at conclusions which are

themselves certain by means of premisses which are false, or

even uncertain. Now, in this perception of yours you are

evidently quite right, but please observe that you cannot

have the conviction you say you have about it except by

trusting your faculties after all. Therefore, if you are con-

vinced, as you say you are, about this impossibility of

attaining conclusions which are certain from false or

uncertain premisses, you must be convinced that your

faculties are not always fallacious, and you must also per-

ceive that your imaginary demon cannot deceive you in

everything.

Therefore, doubt as we may, certainty is the inalienable

possession of even the most absolute sceptic, who, when he

says he is certain of nothing even of his own scepticism

simply contradicts himself, and says what is mere nonsense.

At the outset of this our most important inquiry, namely,

the study of our highest faculties, it is necessary for the

reader thus to see clearly that certainty exists, and that he

not only can but must possess it a'bout some things, or