- MOLLUSCS: THE SURVIVAL GAME (shapeoflife.org)
Their basic body plan includes a foot for mobility; a mantle that secretes a shell and a radula for eating. Molluscs today show many variations on this original body plan. An abalone escapes a sea star predator using its foot; and a moon snail hunts a cockle using its foot as a weapon. The radula has even evolved in an astonishing variety of ways to serve as a tool for feeding. The ancient nautilus was the first mollusc to leave the sea floor. Their ancestors evolved a way to swim using jet propulsion and evolved a way to maintain buoyancy. The evolution of speedy fishes drove the next step in the survival game: speed and loss of the shell, as seen in squid. Octopuses returned to live on the bottom and evolved intelligence and an ability to instantly camouflage itself in order to survive.
- Finally, if there be still persons who are not sufficiently persuaded of the existence of God and of the soul, by the reasons I have adduced, I am desirous that they should know that all the other propositions, of the truth of which they deem themselves perhaps more assured, as that we have a body, and that there exist stars and an earth, and such like, are less certain; for, although we have a moral assurance of these things, which is so strong that there is an appearance of extravagance in doubting of their existence, yet at the same time no one, unless his intellect is impaired, can deny, when the question relates to a metaphysical certitude, that there is sufficient reason to exclude entire assurance, in the observation that when asleep we can in the same way imagine ourselves possessed of another body and that we see other stars and another earth, when there is nothing of the kind.