Correct opinions

For this reason philosophers exhort us not to be contented with mere learning, but to add practice also, and then training. For we have long been accustomed to do the opposite of what we should, and the opinions that we hold and apply are the opposite of the correct ones. If, therefore, we do not also adopt and apply the correct opinions, we shall be nothing more than interpreters of the judgements of others.

~ Epictetus, Discourses 2.9.13-14