If man had not been his own classifier, he would never have thought of founding a separate order for his own reception.

The assumed instinctive belief in God has been used by many persons as an argument for his existence. But this is a rash argument, as we should thus be compelled to believe in the existence of many cruel and malignant spirits, only a little more powerful than man; for the belief in them is far more general than in a beneficent deity.

During my second year at Edinburgh [1826-27] I attended Jameson's lectures on Geology and Zoology, but they were incredible dull. The sole effect they produced on me was the determination never as long as I lived to read a book on Geology.

Even people who aren’t geniuses can outthink the rest of mankind if they develop certain thinking habits.

I am a firm believer, that without speculation there is no good and original observation.

I am not apt to follow blindly the lead of other men

The young blush much more freely than the old but not during infancy, which is remarkable, as we know that infants at a very early age redden from passion.