The most important resources you will ever have are your mind and your mind-set. You must protect them at all costs.
Endless forms most beautiful and most wonderful have been, and are being evolved
It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change, that lives within the means available and works co-operatively against common threats.
The love for all living creatures is the most noble attribute of man.
The world will not be inherited by the strongest, it will be inherited by those most able to change.
A man who dares to waste one hour of time has not discovered the value of life.
Building a better mousetrap merely results in smarter mice.
Some of the things I'm doing probably aren't popular but they're necessary for security and for other reasons.
The mischievous idea that all public needs should be satisfied by compulsory organization and that all the means that individuals are willing to devote to pubic purposes should be under the control of government, is wholly alien to the basic principles of a free society.
Those who sniff decay in every shift of sense or alteration of usage do the language no service. Too often for such people the notion of good English has less to do with expressing ideas clearly than with making words conform to some arbitrary pattern.
I have been too long acquainted with human nature to have great regard for human testimony; and a very great degree of probability, supported by various concurrent circumstances, conspiring in one point, will have much greater weight with me, than human testimony upon oath, or even upon honour; both of which I have frequently seen considerably warped by private views.