The scientific nature of the ordinary man is to go out and do the best you can.

It's generally human nature to overestimate risk and underestimate opportunity.

It is an acknowledged fact that we perceive errors in the work of others more readily than in our own.

I can calculate the motion of heavenly bodies, but not the madness of people.

There is a destiny which has the control of our actions, not to be resisted by the strongest efforts of human nature.

We must take human nature as we find it, perfection falls not to the share of mortals.