We shall never know all the good that a simple smile can do.

Wisdom is the power to put our time and our knowledge to the proper use. 

The price of greatness is responsibility. 

The greatest virtues are those which are most useful to other persons.

In those days he was wiser than he is now; he used to frequently take my advice. 

The things I want to know are in books; my best friend is the man who'll get me a book I didn't read.

Nature's imagination is so boundless compared to our own meager human imagination.

Microsoft has had two goals in the last 10 years. One was to copy the Mac, and the other was to copy Lotus' success in the spreadsheet - basically, the applications business. And over the course of the last 10 years, Microsoft accomplished both of those goals. And now they are completely lost.

Pure mathematics is, in its way, the poetry of logical ideas.

Sense perceptions can be and often are false and deceptive, however real they may appear to us. Where there is realization outside the senses, it is infallible. It is proved not by extraneous evidence but in the transformed conduct and character of those who have felt the real presence of God within.

The most incomprehensible thing about the world is that it is comprehensible. 

To deny people their human rights is to challenge their very humanity.