Book VI · 19

If a thing is difficult to be accomplished by thyself, do not think that it is impossible for man: but if anything is possible for man and conformable to his nature, think that this can be attained by thyself too.

Because thou findest a thing difficult for thyself to accomplish do not conceive it to be impracticable for others; but whatever is possible for a man and in keeping with his nature consider also attainable by thyself.