242 THE GROUNDWORK OF SCIENCE

directly, that it has an enduring permanence, and that the

thought of the day before yesterday was its own thought.

It can know this with a degree of certainty which it is im-

possible to attain to as regards any other fact. To doubt the

continuous existence of our body from day to day would be

absurd indeed, and a sure sign of lunacy ; but to doubt the

continuous existence of the intellect, while illuminated by

a clear memory as to some of its past acts, known with

certainty to have been performed, would be indefinitely still

more absurd.

This power of memory, however, is so wonderful, and the

consequences which follow the recognition of the work it

does are so profound, that it is in no way surprising its value

should have been underestimated. Yet, as we have seen, its

validity cannot be impugned without intellectual suicide and

falling into a fatuous system of universal scepticism. The

self-evident truth that our faculty of memory is valid is one

the acceptance of which is absolutely necessary for the

pursuit of any inquiry, and for the full recognition of what

is for us the most certain of all facts, namely, the fact of our

own existence.

We have now seen (i) that certainty does exist that there

is such a thing as certainty (2) that our own existence is a

most certain fact, and (3) is vouched for by our self-evidently

valid faculty of memory.

But facts alone, however certain and well-remembered,

cannot constitute science without the aid of some abstract

fundamental principles. We require a knowledge of some

principles which are self-evidently true, not only here and

now, but which must be absolutely true ever and always.

Otherwise we could never arrive at certain truths with

respect to any matter of investigation or study. These

principles, also, must not merely be laws and conditions of our

own mind, but must be true of all objects open to our ken,

directly, that it has an enduring permanence, and that the

thought of the day before yesterday was its own thought.

It can know this with a degree of certainty which it is im-

possible to attain to as regards any other fact. To doubt the

continuous existence of our body from day to day would be

absurd indeed, and a sure sign of lunacy ; but to doubt the

continuous existence of the intellect, while illuminated by

a clear memory as to some of its past acts, known with

certainty to have been performed, would be indefinitely still

more absurd.

This power of memory, however, is so wonderful, and the

consequences which follow the recognition of the work it

does are so profound, that it is in no way surprising its value

should have been underestimated. Yet, as we have seen, its

validity cannot be impugned without intellectual suicide and

falling into a fatuous system of universal scepticism. The

self-evident truth that our faculty of memory is valid is one

the acceptance of which is absolutely necessary for the

pursuit of any inquiry, and for the full recognition of what

is for us the most certain of all facts, namely, the fact of our

own existence.

We have now seen (i) that certainty does exist that there

is such a thing as certainty (2) that our own existence is a

most certain fact, and (3) is vouched for by our self-evidently

valid faculty of memory.

But facts alone, however certain and well-remembered,

cannot constitute science without the aid of some abstract

fundamental principles. We require a knowledge of some

principles which are self-evidently true, not only here and

now, but which must be absolutely true ever and always.

Otherwise we could never arrive at certain truths with

respect to any matter of investigation or study. These

principles, also, must not merely be laws and conditions of our

own mind, but must be true of all objects open to our ken,