Doubt grows with knowledge.

Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak, and write.

We know accurately only when we know little, with knowledge doubt increases.

One whose knowledge is confined to books and whose wealth is in the possession of others, can use neither his knowledge nor wealth when the need for them arises.

Knowledge has to be improved, challenged, and increased constantly, or it vanishes.