INTELLECTUAL ANTECEDENTS OF SCIENCE 225

incapable of demonstration or any kind of proof, since it

depends on nothing else. We all of us assume it as a

criterion unconsciously, and it is confidently acted on by

everyone who reasons. But when we ponder over the

matter, we see that what we have thus done spontaneously,

through the natural activity of our intellect, has been done

most reasonably. Did we not adopt it, we should not only

be utterly unable to think logically, but should be plunged

into the most utter and most absurd mental disorganization.

On the other hand, by recognizing that criterion for what

it must be, and is, we gain a secure foundation for our

knowledge, and are enabled to make progress in science.

Our mental condition is, by such recognition, transformed

from a hopeless chaos into an orderly cosmos.

It has now, we trust, been made sufficiently clear to

the attentive reader (what has been incidentally put forward

in earlier chapters) that his own mind that the mind of each

one of us already possesses absolute certainty about some

things, and that his intellect declares that things which are

clearly seen to be evident in and by themselves, possess

the greatest certainty which it is possible for the human

mind to attain to, and that such certainty is abundant.

If one is so unfortunate as not to be able to see this

clearly, and not to be able to have a firm conviction that

there is such a thing as certainty, as also that many

things are actually and in fact certain, then he had better

close this volume and abstain from opening any other work

on science, contenting himself with simple matters, the toils

and pleasures of every-day life, without a thought beyond.

Having satisfied ourselves once for all that certainty exists,

.and that the criterion of certainty is evidence, whereof

intrinsic self-evidence is the highest kind, our next step

should be an endeavour to ascertain what things are most

evident what things are supremely certain.

Q

226 THE GROUNDWORK OF SCIENCE

In our third chapter we contended that we have an

intuition of an external, independent world of extended

things. This is equivalent to the affirmation that extended

things are self-evident, and that we do actually affirm them

so to be. Nevertheless, as we before pointed out,* the self-

evidence and certainty of the existence of such an external

world do not attain to the very highest degree of certainty

and evidence. They have not this pre-eminence, because we

have to obtain their certainty through the ministry of the

senses, by the aid of which, together with reflexion, we

recognize the action of external bodies upon us, and the

sensations they excite within us, through which (without

our at first attending to and recognizing our sensations)

such bodies are made present to our minds so that we

perceive them. The fact that we gain this perception by so

complex a process (though, through it, we cognize objects

directly and not reflexly, or by inference),! makes us able to

entertain a sort of fictitious doubt about the nature of our

perceptions of external things, but for which all Idealism

would be absolutely impossible. We may (because many

persons do) believe that our inevitable perception of the

world about us is either an inference or a delusion, even

to the extent of regarding ourselves as the one only cause

of everything we perceive that is to say, we may accept

solipsism. As our own body is, for our mind, one portion,

though a very peculiar portion, of the external world, doubts

which may be entertained about that world must apply also

to it. Moreover, what we perceive with the greatest certainty

about the external world is just that which our senses do

not and cannot show us. That secondary qualities should

be objectively, very different from what we subjectively feel

them to be we can easily admit ; but that, underlying them,

there should not be an unperceived and imperceptible

* See ante, p.. 47. f See ante, p. 63.

incapable of demonstration or any kind of proof, since it

depends on nothing else. We all of us assume it as a

criterion unconsciously, and it is confidently acted on by

everyone who reasons. But when we ponder over the

matter, we see that what we have thus done spontaneously,

through the natural activity of our intellect, has been done

most reasonably. Did we not adopt it, we should not only

be utterly unable to think logically, but should be plunged

into the most utter and most absurd mental disorganization.

On the other hand, by recognizing that criterion for what

it must be, and is, we gain a secure foundation for our

knowledge, and are enabled to make progress in science.

Our mental condition is, by such recognition, transformed

from a hopeless chaos into an orderly cosmos.

It has now, we trust, been made sufficiently clear to

the attentive reader (what has been incidentally put forward

in earlier chapters) that his own mind that the mind of each

one of us already possesses absolute certainty about some

things, and that his intellect declares that things which are

clearly seen to be evident in and by themselves, possess

the greatest certainty which it is possible for the human

mind to attain to, and that such certainty is abundant.

If one is so unfortunate as not to be able to see this

clearly, and not to be able to have a firm conviction that

there is such a thing as certainty, as also that many

things are actually and in fact certain, then he had better

close this volume and abstain from opening any other work

on science, contenting himself with simple matters, the toils

and pleasures of every-day life, without a thought beyond.

Having satisfied ourselves once for all that certainty exists,

.and that the criterion of certainty is evidence, whereof

intrinsic self-evidence is the highest kind, our next step

should be an endeavour to ascertain what things are most

evident what things are supremely certain.

Q

226 THE GROUNDWORK OF SCIENCE

In our third chapter we contended that we have an

intuition of an external, independent world of extended

things. This is equivalent to the affirmation that extended

things are self-evident, and that we do actually affirm them

so to be. Nevertheless, as we before pointed out,* the self-

evidence and certainty of the existence of such an external

world do not attain to the very highest degree of certainty

and evidence. They have not this pre-eminence, because we

have to obtain their certainty through the ministry of the

senses, by the aid of which, together with reflexion, we

recognize the action of external bodies upon us, and the

sensations they excite within us, through which (without

our at first attending to and recognizing our sensations)

such bodies are made present to our minds so that we

perceive them. The fact that we gain this perception by so

complex a process (though, through it, we cognize objects

directly and not reflexly, or by inference),! makes us able to

entertain a sort of fictitious doubt about the nature of our

perceptions of external things, but for which all Idealism

would be absolutely impossible. We may (because many

persons do) believe that our inevitable perception of the

world about us is either an inference or a delusion, even

to the extent of regarding ourselves as the one only cause

of everything we perceive that is to say, we may accept

solipsism. As our own body is, for our mind, one portion,

though a very peculiar portion, of the external world, doubts

which may be entertained about that world must apply also

to it. Moreover, what we perceive with the greatest certainty

about the external world is just that which our senses do

not and cannot show us. That secondary qualities should

be objectively, very different from what we subjectively feel

them to be we can easily admit ; but that, underlying them,

there should not be an unperceived and imperceptible

* See ante, p.. 47. f See ante, p. 63.