The moral virtues, then, are produced in us neither by nature nor against nature. Nature, indeed, prepares in us the ground for their reception, but their complete formation is the product of habit.
Those herbs which perfume the air most delightfully, not passed by as the rest, but, being trodden upon and crushed, are three; that is, burnet, wild thyme and watermints. Therefore, you are to set whole alleys of them, to have the pleasure when you walk or tread.
I will begin with what in my opinion is your lack of restraint. You are like a spectator in a theatre who expresses his enthusiasm so unrestrainedly that he prevents himself and others from hearing. That lack of restraint is particularly noticeable in the descriptions of nature with which you interrupt dialogues; when one reads them, these descriptions, one wishes they were more compact, shorter, say two or three lines.
My scientific work is motivated by an irresistible longing to understand the secrets of nature and by no other feeling. My love for justice and striving to contribute towards the improvement of human conditions are quite independent from my scientific interests.
For nature by the same cause, provided it remain in the same condition, always produces the same effect, so that either coming-to-be or passing-away will always result.