. . . As to self-improvement, the true Catholic mode of learning is to "prove all things," as far as we can, without sin or the danger of it, to "hold fast that which is good." Let us never be afraid of trying anything new, learnt from people of different opinions to our own. And let us never be afraid of changing our opinions. The unwillingness to go back from once declared opinion is a form of pride which haunts some powerful minds: but it is not found in great childlike geniuses. Fools may hold fast to their scanty stock through life, and we must be very cautious in drawing them from it -- for where can they supply its place?

Letters and Memories. 1843.