ceive," (alluding to the minuteness of fern seeds, and the mechanism employed to disperse them,) "with what rapidity they may be wafted about by the wind, so as to account for these plants being found on the tops of the highest trees, and on walls, wherever they can find mould enough to take root in.
"The great obscurity of the human understanding is clearly proved by this observation, for, if it were not very dark indeed, how could it, during so many ages, deny that this plant had either seeds or flowers? insomuch that it was one of the first errors taught young people in books, as well as heard in conversation. We ought, therefore, to thank the Sun of divine grace, and true fountain of all useful knowledge, that we are at last so happy as to attain more just notions of this matter. Should not this mistake teach us modesty in our opinions and our judgment upon many other occasions, seeing upon this the most penetrating geniuses have all gone astray? If we are so liable to mistakes in regard to things that lie open to our inspection, what are we to say of our opinions of things that are invisible? How many idle notions are formed on such subjects! how many senseless conceits, with which, however, we sometimes suffer ourselves so far to be deluded that we make nothing of injuring, both in character and person, those who happen to be of a contrary opinion! It is therefore, absolutely necessary that we should always distrust ourselves and act with the greatest circumspection. In our present wretched condition, we are surrounded with ignorance on every side, and
