Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.
There are gems of wondrous brightness
Ofttimes lying at our feet,
And we pass them, walking thoughtless,
Down the busy, crowded street.
If we knew, our pace would slacken,
We would step more oft with care,
Lest our careless feet be treading
To the earth some jewel rare.
Erudition, like a bloodhound, is a charming thing when held firmly in leash, but it is not so attractive when turned loose upon a defenseless and unerudite public.
The nearer a conception comes towards finality, the nearer does the dynamic relation, out of which this concept has arisen, draw to a close. To know is to lose.
My praise shall be dedicated to the mind itself. The mind is the man, and the knowledge is the mind. A man is but what he knoweth. The mind is but an accident to knowledge, for knowledge is the double of that which is.
It must be conceded that a theory has an important advantage if its basic concepts and fundamental hypotheses are 'close to experience,' and greater confidence in such a theory is certainly justified. There is less danger of going completely astray, particularly since it takes so much less time and effort to disprove such theories by experience. Yet more and more, as the depth of our knowledge increases, we must give up this advantage in our quest for logical simplicity in the foundations of physical theory.