Comforts and syphilis are the greatest enemies of mankind.
The quality of life is more important than life itself.
The difficulty of finding organs suitable for transplantation on man must be met.
The most efficient way to live reasonably is every morning to make a plan of one's day and every night to examine the results obtained.
A few observation and much reasoning lead to error; many observations and a little reasoning to truth.
In man, the things which are not measurable are more important than those which are measurable.