The Origin and Growth of the Healing Art by Edward Berdoe

having acquired a true knowledge of it, we shall then, in travelling through the cities, be esteemed physicians not only in name but in reality. But inexperience is a bad treasure, and a bad friend to those who possess it, whether in opinion or reality, being devoid of self-reliance and contentedness, and the nurse both of timidity and audacity. For timidity betrays a want of power, and audacity a want of skill. There are, indeed, two things, knowledge and opinion, of which the one makes its possessor really to know, the other to be ignorant.