Nitpick: the Einstein quote is predated by Nicolas Boileau in l'Art Poétique (1674)

    Avant donc que d'écrire, apprenez à penser.
    Selon que notre idée est plus ou moins obscure,
    L'expression la suit, ou moins nette, ou plus pure. 
    Ce que l'on conçoit bien s'énonce clairement,
    Et les mots pour le dire arrivent aisément.

Translated on the spot (as a futile attempt from a non-native speaker to preserve the poetry of it):

    Before even to write, one should learn to think.
    As the idea is more or less obscure
    Expression follows, 'ther less clear, or more pure.
    What's best understood is uttered clearly,
    And those words to tell come that easily.

I'm always surprised how much such a work originally applying to art and poetry is also relevant to code. Another example:

    Hâtez-vous lentement, et sans perdre courage,
    Vingt fois sur le métier remettez votre ouvrage,
    Polissez-le sans cesse, et le repolissez,
    Ajoutez quelquefois, et souvent effacez.

T9n:

    Haste yourself slowly, keep up with bravery,
    Your work on the bench put again a twenty,
    Endlessly you polish, and again polish it,
    Occasionally add, much often delete.