136 THE GROUNDWORK OF SCIENCE

of instinct. So we think no more need be said here upon

that subject.

More remarkable still are the results produced by means

of those structures we term "organs of sense." Were we

pure intelligences devoid of bodies and ignorant of the

characteristic psychical endowments of animals, there is

nothing in an eye which could lead us to suppose that the

inverted .picture thrown upon the backs of a pair of them

could enable their possessor to see real external objects,

and to see them upright and single, and not inverted and

double, as they are in each man's pair of eyes. Of course,

the mere eyes could not see apart from the brain or apart

from the brain's rich supply of duly conditioned blood, etc.

Where sight takes place, who knows? The exact nature

of the relation of the brain and its parts to actual visual

cognition, who can tell ? Moreover, as we have seen, the

brain is double as well as the organ of sight. But the

practical outcome of an organization so incomprehensible

in its innermost nature is none the less satisfactory. That

the perception of the eyes is valid, and the cognitions it

affords are true, can be shown by comparing small solid

objects apprehended by our sight with the same objects

as known to us by the use of our hands. Not that we have

any ground for considering our physical means of sight less

perfect than any other possible physical means any organ

which was not an eye for obtaining a visual knowledge

of objectivity. No such means, which we can in any way

imagine, could appear better adapted or less mysterious,

because every psychical result of physical antecedents is

most absolutely mysterious But we can hence at least

obtain one practical lesson the lesson, namely, that because

we do not know how our bodily organization enables us to

obtain a real and true knowledge of what is objective, we

can be none the less sure that it does enable us to obtain

of instinct. So we think no more need be said here upon

that subject.

More remarkable still are the results produced by means

of those structures we term "organs of sense." Were we

pure intelligences devoid of bodies and ignorant of the

characteristic psychical endowments of animals, there is

nothing in an eye which could lead us to suppose that the

inverted .picture thrown upon the backs of a pair of them

could enable their possessor to see real external objects,

and to see them upright and single, and not inverted and

double, as they are in each man's pair of eyes. Of course,

the mere eyes could not see apart from the brain or apart

from the brain's rich supply of duly conditioned blood, etc.

Where sight takes place, who knows? The exact nature

of the relation of the brain and its parts to actual visual

cognition, who can tell ? Moreover, as we have seen, the

brain is double as well as the organ of sight. But the

practical outcome of an organization so incomprehensible

in its innermost nature is none the less satisfactory. That

the perception of the eyes is valid, and the cognitions it

affords are true, can be shown by comparing small solid

objects apprehended by our sight with the same objects

as known to us by the use of our hands. Not that we have

any ground for considering our physical means of sight less

perfect than any other possible physical means any organ

which was not an eye for obtaining a visual knowledge

of objectivity. No such means, which we can in any way

imagine, could appear better adapted or less mysterious,

because every psychical result of physical antecedents is

most absolutely mysterious But we can hence at least

obtain one practical lesson the lesson, namely, that because

we do not know how our bodily organization enables us to

obtain a real and true knowledge of what is objective, we

can be none the less sure that it does enable us to obtain