To know how little one knows is to have genuine knowledge. Not to know how little one knows is to be deluded. Only those who know when they are deluded can free themselves from such delusion. The intelligent people are not deluded, because they know and accept their ignorance as ignorance, and thereby have genuine knowledge.
[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.]
In Philosophy, the contemplations of man do either penetrate unto God, or are circumferred to Nature, or are reflected and reverted upon himself. Out of which several inquiries there do arise three knowledges, Divine Philosophy, Natural Philosophy, and Human Philosophy or Humanity. For all things are marked and stamped with this triple character of the power of God, the difference of Nature and the use of Man.
Knowing things halfway is a greater success than knowing things completely: it takes things to be simpler than they really are andso makes its opinions more easily understandable and persuasive.
And what avails it that science has come to treat space and time as simply forms of thought, and the material world as hypothetical, and withal our pretension of property and even of self-hood are fading with the rest, if, at last, even our thoughts are not finalities, but the incessant flowing and ascension reach these also, and each thought which yesterday was a finality, to-day is yielding to a larger generalization?
Metaphysical world.- It is true, there could be a metaphysical world; the absolute possibility of it is hardly to be disputed. We behold all things through the human head and cannot cut off this head; while the question nonetheless remains what of the world would still be there if one had cut it off.