Epictetus, Golden Sayings 109

If what charms you is nothing but abstract principles, sit down and turn them over quietly in your mind, but never dub yourself a Philosopher, nor suffer others to call you so. 

Say rather: He is in error; for my desires, my impulses are unaltered. I give in my adhesion to what I did before; nor has my mode of dealing with the things of sense undergone any change.