318 THE GROUNDWORK OF SCIENCE

leather," and they may recognize the fact that an habitual

employment of the mind and energies in one special pursuit

can prevent men from being able readily to apply themselves

to another of a very different kind. Nevertheless, as a rule,

they have no proximately correct appreciation either of the

wonderfully lofty nature of their mental powers or of the

warping and narrowing effect of prejudice in hampering

their exercise. As the late Cardinal Newman truly observed

many years ago : "Any one study, of whatever kind, exclusively

pursued, deadens in the mind the interest, nay the perception,

of any others. Thus Cicero says that Plato and Demosthenes,

Aristotle and Isocrates might have respectively excelled in

each other's province, but that each was absorbed in his own.

Specimens of this peculiarity occur every day. You can

hardly persuade some men to talk about anything but their

own pursuit ; they refer the whole world to their own centre,

and measure all matters by their own rule, like the fisherman

in the drama, whose eulogy on his deceased lord was, that

' he was so fond of fish.' "

This tendency to mental onesidedness, arising from the

almost exclusive study of one side of nature, has as

experience convinces us, made not a few able men, exclu-

sively devoted to the study of one or more physical

sciences, less able, than would have been the case had their

culture been wider, to appreciate and assign full weight to

the facts of mental and, above all, of metaphysical science.

The one great requisite for the study and correct estimate

of the nature of things external to ourselves, is true and

accurate knowledge of our own. It is necessary for us to

recognize that we are not only conscious but conscious of

our consciousness ; that we not only can make use of and

be guided by inference, but that we are capable of analyzing

the process of inference, and that we can not only act well

or ill, but can recognize an ethical ideal. We require to

leather," and they may recognize the fact that an habitual

employment of the mind and energies in one special pursuit

can prevent men from being able readily to apply themselves

to another of a very different kind. Nevertheless, as a rule,

they have no proximately correct appreciation either of the

wonderfully lofty nature of their mental powers or of the

warping and narrowing effect of prejudice in hampering

their exercise. As the late Cardinal Newman truly observed

many years ago : "Any one study, of whatever kind, exclusively

pursued, deadens in the mind the interest, nay the perception,

of any others. Thus Cicero says that Plato and Demosthenes,

Aristotle and Isocrates might have respectively excelled in

each other's province, but that each was absorbed in his own.

Specimens of this peculiarity occur every day. You can

hardly persuade some men to talk about anything but their

own pursuit ; they refer the whole world to their own centre,

and measure all matters by their own rule, like the fisherman

in the drama, whose eulogy on his deceased lord was, that

' he was so fond of fish.' "

This tendency to mental onesidedness, arising from the

almost exclusive study of one side of nature, has as

experience convinces us, made not a few able men, exclu-

sively devoted to the study of one or more physical

sciences, less able, than would have been the case had their

culture been wider, to appreciate and assign full weight to

the facts of mental and, above all, of metaphysical science.

The one great requisite for the study and correct estimate

of the nature of things external to ourselves, is true and

accurate knowledge of our own. It is necessary for us to

recognize that we are not only conscious but conscious of

our consciousness ; that we not only can make use of and

be guided by inference, but that we are capable of analyzing

the process of inference, and that we can not only act well

or ill, but can recognize an ethical ideal. We require to