They see not so much your nature as your artifices

From Montaigne’s De Repentir (Book 3, essay 2)

J’ay mes loix et ma court pour juger de moy, et m’y adresse plus qu’ailleurs. Je restrainsbien selon autruy mes actions, mais je ne les estends que selon moy. Il n’y a que vous qui sçache si vous estes lache et cruel, ou loyal et devotieux ; les autres nevous voyent poinct, ils vous devinent par conjectures incertaines ; ils voyent nontant vostre nature que vostre art. Par ainsi ne vous tenez pas à leur sentence ; tenez vous à la vostre. Tuo tibi judicio est utendum. Virtutis et vitiorum graveipsius conscientiae pondus est : qua sublata, jacent omnia.

Someone’s translation borrowed pulled from online because I don’t feel like typing out a paragraph:

I have my own laws and my own court to judge me, and I refer to these rather than elsewhere. I certainly restrain my actions out of deference to others, but I understand them only by my own light, None but you know whether you are cruel and cowardly, or loyal and dutiful. Others have no vision of you, but judge of you by uncertain conjectures; they see not so much your nature as your artifices. Do not rely on their opinions, therefore; rely on your own.