Man, being the servant and interpreter of Nature, can do and understand so much and so much only as he has observed in fact or thought of the course of nature; beyond this he neither knows anything nor can do anything.
Some men covet knowledge out of a natural curiosity and inquisitive temper; some to entertain the mind with variety and delight; some for ornament and reputation; some for victory and contention; many for lucre and a livelihood; and but few for employing the Divine gift of reason to the use and benefit of mankind.
To realize that our knowledge is ignorance, This is a noble insight. To regard our ignorance as knowledge, This is mental sickness. Only when we are sick of the sickness Shall we cease to be sick. The Sage is not sick, being sick of sickness; This is the secret of health.
I like to have a person's knowledge comprehend more than one class of topics, one row of shelves. I like a person who likes to see a fine barn as well as a good tragedy.
From whatever you wish to know and measure you must take your leave, at least for a time. Only when you have left the town can yousee how high its towers rise above the houses.
[Misquotation; not by Einstein.] If only I had known, I should have become a watchmaker. [Apparently remorseful for his role in the development of the atom bomb.]
Not to know what has been transacted in former times is to be always a child. If no use is made of the labors of past ages, the world must remain always in the infancy of knowledge.
The true bounds and limitations, whereby human knowledge is confined and circumscribed,... are three: the first, that we do not so place our felicity in knowledge, as we forget our mortality: the second, that we make application of our knowledge, to give ourselves repose and contentment, and not distates or repining: the third, that we do not presume by the contemplation of Nature to attain to the mysteries of God.