The mathematician's patterns, like the painter's or the poet's, must be beautiful.

Change is hard, but it is necessary for progress.

No man, for any considerable period, can wear one face to himself and another to the multitude, without finally getting bewildered as to which may be the true.

领导者的力量在于他们适应并激励他人接受变化的能力。

【解释】人常常在忧患困苦中，才能磨练意志，增长才干。