在皮亞傑1946年所出版的《兒童的時間概念(The Child s Conception of Time)》的序中提到:
This work was prompted by a number of questions kindly suggested by Albert Einstein more than fifteen years ago when he presided over the first international course of lectures on philosophy and psychology at Davos.Is our intuitive grasp of time primitive or derived?Is it identical with our intuitive grasp of velocity?What if any bearing do these questions have on the genesis and development of the child s conception of time?