Francesco Guicciardini Quote
If displeased with any man, do all you can to prevent his seeing it, for otherwise he will become estranged. And occasions often arise when he might and would have served you had you not lost him by showing your dislike. Of this I have had experience to my own profit. For once and again I have felt ill-disposed towards some one who not being aware of my hostility has afterwards helped me when I needed help and proved my good friend.
Number 324. - Counsels and Reflections (1857)