If any man can convince me and bring home to me that I do not think or act aright, gladly will I change; for I search after truth, by which man never yet was harmed. But he is harmed who abideth on still in his deception and ignorance.

Remember that all is opinion.

To no man make yourself a boon companion: Your joy will be less but less will be your grief

An angry look on the face is wholly against nature. If it be assumed frequently, beauty begins to perish, and in the end is quenched beyond rekindling.

Let it judge that nothing is either bad or good which can happen equally to the bad man and the good. For that which happens equally to him who lives contrary to nature and to him who lives according to nature, is neither according to nature nor contrary to nature.

...the sole thing of which any man can be deprived is the present; since this is all he owns, and nobody can lose what is not his.

If you do the task before you always adhering to strict reason with zeal and energy and yet with humanity, disregarding all lesser ends and keeping the divinity within you pure and upright, as though you were even now faced with its recall - if you hold steadily to this, staying for nothing and shrinking from nothing, only seeking in each passing action a conformity with nature and in each word and utterance a fearless truthfulness, then the good life shall be yours. And from this course no man has the power to hold you back.