I, like other searchers, attempt formulation after formulation of the central issues...taking for a working hypothesis the most effective one that has survived this winnowing: It from bit. Otherwise put, every it -every particle, every force, even the spacetime continuum itself- derives its function, its meaning, its very existence entirely-even if in some contexts indirectly-from the apparatus-elicited answers to yes-or-no questions, binary choices, bits.
It from bit symbolizes the idea that the physical world has at bottom- at a very deep bottom , in most instances-an immaterial source and explanation; that which we call reality arises in the last analysis from the posing of yes-no questions and the registering of equipment-evoked responses; in short, that all things physical are information-theoretic in origin and this is a participatory universe.

John Archibald Wheeler, Information, Physics, Quantum: The Search for Links. In Complexity, Entropy and the Physics of Information, SFI Studies in the Sciences of Complexity, vol VIII, Ed. W. H. Zurek (1990).


Another's hand behaves just as though on touching a fire a feeling of pain occurred, another's lips as though volitions were acting on them. Of these alien sensations and volitions we have not the least knowledge, but know only our own ideas of them with which we operate as with those of our own senses and volitions, thus obtaining useful rules for constructing and predicting the course of our sensations relating to the bodies of others. Thus our conception of the sensations and volitions of others is merely the expression for certain equations always holding between the behavior of our sensations relative to our own and other people's bodies; it is in a pre-eminent sense what we call an analogy (albeit not a mechanical but a psychological one).

Ludwig Boltzmann, Populare Schriften (Writings Addressed to the Public), Objective Existence in Inanimate Nature (1886).


What lies at the heart of every living thing is not a fire, not warm breath, not a 'spark of life.' It is information, words, instructions. If you want a metaphor, don't think of fires and sparks and breath. Think, instead, of a billion discrete, digital characters carved in tablets of crystal. If you want to understand life, don't think about vibrant, throbbing gels and oozes, think about information technology.

Richard Dawkins, The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design (1986).


But other questions come upon us. What is a man's eye but a machine for the little creature that sits behind in his brain to look through? A dead eye is nearly as good as a living one for some time after the man is dead. It is not the eye that cannot see, but the restless one that cannot see through it. Is it man's eyes, or is it the big seeing-engine which has revealed to us the existence of worlds beyond worlds into infinity? What has made man familiar with the scenery of the moon, the spots on the sun, or the geography of the planets? He is at the mercy of the seeing-engine for these things, and is powerless unless he tack it on to his own identity, and make it part and parcel of himself. Or, again, is it the eye, or the little see-engine, which has shown us the existence of infinitely minute organisms which swarm unsuspected around us?

Samuel Butler, Erwehon (1872). [link to full text]


Complex now, but how much simpler and more intelligibly organized may it not become in another hundred thousand years? or in twenty thousand? For man at present believes that his interest lies in that direction; he spends incalculable amount of labour and time and thought in making machines breed always better and better; he has already succeeded in effecting much that at one time appeared impossible, and there seem no limits to the results of accumulated improvements if they are allowed to descend with modification from generation to generation. It must always be remembered that man's body is what it is through having been moulded into its present shape by the chances and changes of many millions of years, but that his organisation never advanced with anything like the rapidity with which that of the machines is advancing. This is the most alarming feature of the case, and I must be pardoned for insisting on it so frequently.

Samuel Butler, Erwehon (1872). [link to full text]


We grant a number to an abacus when we interpret the arrangement of beads as expressing that number. In the same way, we might grant a conscious soul to a robot by interpretting its behavior as expressing the action of such a soul; the more humanlike its interaction with us, the easier the attribution.

Hans Moravec, Robot (1999).


I will suppose, then, not that Deity, who is sovereignly good and the fountain of truth, but that some malignant demon, who is at once exceedingly potent and deceitful, has employed all his artifice to deceive me; I will suppose that the sky, the air, the earth, colors, figures, sounds, and all external things, are nothing better than the illusions of dreams, by means of which this being has laid snares for my credulity; I will consider myself as without hands, eyes, flesh, blood, or any of the senses, and as falsely believing that I am possessed of these; I will continue resolutely fixed in this belief, and if indeed by this means it be not in my power to arrive at the knowledge of truth, I shall at least do what is in my power, and guard with settled purpose against giving my assent to what is false, and being imposed upon by this deceiver, whatever be his power and artifice.

Rene Descartes, Meditations (1641). [link to full text]

Comments and corrections to: kate@nat.vu.nl (Kate Mullen)