Daniel Hjertholm

“All honor to those who can abnegate for themselves the personal enjoyment of life, when by such renunciation they contribute worthily to increase the amount of happiness in the world; but he who does it, or professes to do it, for any other purpose, is no more deserving of admiration than the ascetic mounted on his pillar.”
― John Stuart Mill, Utilitarianism

“The utilitarian morality does recognise in human beings the power of sacrificing their own greatest good for the good of others. It only refuses to admit that the sacrifice is itself a good. A sacrifice which does not increase, or tend to increase, the sum total of happiness, it considers as wasted.”
― John Stuart Mill, Utilitarianism

“It is a strange notion that the acknowledgment of a first principle is inconsistent with the admission of secondary ones. To inform a traveler respecting the place of his ultimate destination, is not to forbid the use of land-marks and direction-posts on the way. The proposition that happiness is the end and aim of morality, does not mean that no road ought to be laid down to that goal, or that persons going thither should not be advised to take one direction rather than another. Men really ought to leave off talking a kind of nonsense on this subject, which they would neither talk nor listen to on other matters of practical concernment. Nobody argues that the art of navigation is not founded on astronomy, because sailors cannot wait to calculate the Nautical Almanack. Being rational creatures, they go to sea with it ready calculated; and all rational creatures go out upon the sea of life with their minds made up on the common questions of right and wrong, as well as on many of the far more difficult questions of wise and foolish. And this, as long as foresight is a human quality, it is to be presumed they will continue to do. Whatever we adopt as the fundamental principle of morality, we require subordinate principles to apply it by: the impossibility of doing without them, being common to all systems, can afford no argument against any one in particular: but gravely to argue as if no such secondary principles could be had, and as if mankind had remained till now, and always must remain, without drawing any general conclusions from the experience of human life, is as high a pitch, I think, as absurdity has ever reached in philosophical controversy.”
― John Stuart Mill, Utilitarianism

“However, questions arise. Are there people who aren't naive realists, or special situations in which naive realism disappears? My theory—the self-model theory of subjectivity—predicts that as soon as a conscious representation becomes opaque (that is, as soon as we experience it as a representation), we lose naive realism. Consciousness without naive realism does exist. This happens whenever, with the help of other, second-order representations, we become aware of the construction process—of all the ambiguities and dynamical stages preceding the stable state that emerges at the end. When the window is dirty or cracked, we immediately realize that conscious perception is only an interface, and we become aware of the medium itself. We doubt that our sensory organs are working properly. We doubt the existence of whatever it is we are seeing or feeling, and we realize that the medium itself is fallible. In short, if the book in your hands lost its transparency, you would experience it as a state of your mind rather than as an element of the outside world. You would immediately doubt its independent existence. It would be more like a book-thought than a book-perception. Precisely this happens in various situations—for example, In visual hallucinations during which the patient is aware of hallucinating, or in ordinary optical illusions when we suddenly become aware that we are not in immediate contact with reality. Normally, such experiences make us think something is wrong with our eyes. If you could consciously experience earlier processing stages of the representation of the book In your hands, the image would probably become unstable and ambiguous; it would start to breathe and move slightly. Its surface would become iridescent, shining in different colors at the same time. Immediately you would ask yourself whether this could be a dream, whether there was something wrong with your eyes, whether someone had mixed a potent hallucinogen into your drink. A segment of the wall of the Ego Tunnel would have lost its transparency, and the self-constructed nature of the overall flow of experience would dawn on you. In a nonconceptual and entirely nontheoretical way, you would suddenly gain a deeper understanding of the fact that this world, at this very moment, only appears to you.”
― Thomas Metzinger, The Ego Tunnel: The Science of the Mind and the Myth of the Self