70 THE GROUNDWORK OF SCIENCE

light, colour, and sound as are the conceptions of ordinary

persons with respect to the latter.

Bearing these facts in mind, let us once more consider some

objections made by Idealists against those who believe in an

independent, external world of real, extended objects possess-

ing real, objective qualities.

The iridescent tints of minutely grooved surfaces do not

really deceive any more than the effects of coloured lights or

tinted glasses, or than distant mountains which look purple

make us suppose that they are actually purple when seen

close at hand.

The effects of bodily injuries are often cited as evidence of

the untrustworthiness of judgments our sensations induce.

Men who have had a leg amputated sometimes feel as if they

still had it, and also feel pains in their vanished toes. But no

one would surely be so foolish as to pretend that our feelings,

or even our preceptions, are independent of our bodily

organization ; if, then, that organization be impaired, the

action of our sensitive faculty would be likewise impaired,

nor should we be surprised if our perceptions were thereby

also occasionally misled. If our normal organization is so

arranged as to guide us right, it should be small wonder to us

if it sometimes guided us wrongly when in an abnormal

condition ! But, after all, even though a man whose leg has

been amputated may suffer with pains like those he might

feel if he still had his toes, that does not lead him to believe

that he has actually still got them !

If objects may appear different in size and shape as

we change our place in respect to them, though they in

truth do not so change at all, not only are we not thereby

deceived, but, as we have seen,* our knowledge of their

objective qualities may be thereby perfected. A pea held

between our crossed first and middle fingers will not feel

* See ante, p. 61.

light, colour, and sound as are the conceptions of ordinary

persons with respect to the latter.

Bearing these facts in mind, let us once more consider some

objections made by Idealists against those who believe in an

independent, external world of real, extended objects possess-

ing real, objective qualities.

The iridescent tints of minutely grooved surfaces do not

really deceive any more than the effects of coloured lights or

tinted glasses, or than distant mountains which look purple

make us suppose that they are actually purple when seen

close at hand.

The effects of bodily injuries are often cited as evidence of

the untrustworthiness of judgments our sensations induce.

Men who have had a leg amputated sometimes feel as if they

still had it, and also feel pains in their vanished toes. But no

one would surely be so foolish as to pretend that our feelings,

or even our preceptions, are independent of our bodily

organization ; if, then, that organization be impaired, the

action of our sensitive faculty would be likewise impaired,

nor should we be surprised if our perceptions were thereby

also occasionally misled. If our normal organization is so

arranged as to guide us right, it should be small wonder to us

if it sometimes guided us wrongly when in an abnormal

condition ! But, after all, even though a man whose leg has

been amputated may suffer with pains like those he might

feel if he still had his toes, that does not lead him to believe

that he has actually still got them !

If objects may appear different in size and shape as

we change our place in respect to them, though they in

truth do not so change at all, not only are we not thereby

deceived, but, as we have seen,* our knowledge of their

objective qualities may be thereby perfected. A pea held

between our crossed first and middle fingers will not feel

* See ante, p. 61.