"Because your own strength is unequal to the task, do not assume that it is beyond the powers of man; but if anything is within the powers and province of man, believe that it is within your own compass also"

This quote by Marcus Aurelius suggests that just because somebody can not accomplish something on their own, they ought to not presume that it is impossible for all of mankind. Nevertheless, if something is attainable by human beings, the person should trust their own ability to accomplish it. Basically, the quote motivates individuals to recognize their limitations however also to believe in their capabilities.