Thinking

   1) I Am a Thinking Thing

   But what then am I? A thing which thinks. What is a thing which thinks? It is a thing which doubts, understands, [conceives], affirms, denies, wills, refuses, which also imagines and feels. (Descartes, 1951, p. 153)

   2) Thinking Is Not Independent of the Expression of Thought

   I have been trying in all this to remove the temptation to think that there "must be" a mental process of thinking, hoping, wishing, believing, etc., independent of the process of expressing a thought, a hope, a wish, etc. . . . If we scrutinize the usages which we make of "thinking," "meaning," "wishing," etc., going through this process rids us of the temptation to look for a peculiar act of thinking, independent of the act of expressing our thoughts, and stowed away in some particular medium. (Wittgenstein, 1958, pp. 41-43)

   3) The Experimental Differentiation of Concrete and Propositional Operations

   Analyse the proofs employed by the subject. If they do not go beyond observation of empirical correspondences, they can be fully explained in terms of concrete operations, and nothing would warrant our assuming that more complex thought mechanisms are operating. If, on the other hand, the subject interprets a given correspondence as the result of any one of several possible combinations, and this leads him to verify his hypotheses by observing their consequences, we know that propositional operations are involved. (Inhelder & Piaget, 1958, p. 279)

   4) In Every Age, Philosophical Thinking Exploits Some Dominant Concepts

   In every age, philosophical thinking exploits some dominant concepts and makes its greatest headway in solving problems conceived in terms of them. The seventeenth- and eighteenth-century philosophers construed knowledge, knower, and known in terms of sense data and their association. Descartes' self-examination gave classical psychology the mind and its contents as a starting point. Locke set up sensory immediacy as the new criterion of the real . . . Hobbes provided the genetic method of building up complex ideas from simple ones . . . and, in another quarter, still true to the Hobbesian method, Pavlov built intellect out of conditioned reflexes and Loeb built life out of tropisms. (S. Langer, 1962, p. 54)

   5) The Experimental Differentiation of Deductive and Inductive Reasoning

   Experiments on deductive reasoning show that subjects are influenced sufficiently by their experience for their reasoning to differ from that described by a purely deductive system, whilst experiments on inductive reasoning lead to the view that an understanding of the strategies used by adult subjects in attaining concepts involves reference to higher-order concepts of a logical and deductive nature. (Bolton, 1972, p. 154)

   6) The Power of Machine Thought

   There are now machines in the world that think, that learn and create. Moreover, their ability to do these things is going to increase rapidly until-in the visible future-the range of problems they can handle will be coextensive with the range to which the human mind has been applied. (Newell & Simon, quoted in Weizenbaum, 1976, p. 138)

   7) Thinking Is Sometimes Accompanied by Action and Sometimes Not

   But how does it happen that thinking is sometimes accompanied by action and sometimes not, sometimes by motion, and sometimes not? It looks as if almost the same thing happens as in the case of reasoning and making inferences about unchanging objects. But in that case the end is a speculative proposition . . . whereas here the conclusion which results from the two premises is an action. . . . I need covering; a cloak is a covering. I need a cloak. What I need, I have to make; I need a cloak. I have to make a cloak. And the conclusion, the "I have to make a cloak," is an action. (Nussbaum, 1978, p. 40)

   8) The Growth of Philosophy

   It is well to remember that when philosophy emerged in Greece in the sixth century, B.C., it did not burst suddenly out of the Mediterranean blue. The development of societies of reasoning creatures-what we call civilization-had been a process to be measured not in thousands but in millions of years. Human beings became civilized as they became reasonable, and for an animal to begin to reason and to learn how to improve its reasoning is a long, slow process. So thinking had been going on for ages before Greece-slowly improving itself, uncovering the pitfalls to be avoided by forethought, endeavoring to weigh alternative sets of consequences intellectually. What happened in the sixth century, B.C., is that thinking turned round on itself; people began to think about thinking, and the momentous event, the culmination of the long process to that point, was in fact the birth of philosophy. (Lipman, Sharp & Oscanyan, 1980, p. xi)

   9) Thought Is, in Great Part, a Public Activity

   The way to look at thought is not to assume that there is a parallel thread of correlated affects or internal experiences that go with it in some regular way. It's not of course that people don't have internal experiences, of course they do; but that when you ask what is the state of mind of someone, say while he or she is performing a ritual, it's hard to believe that such experiences are the same for all people involved. . . . The thinking, and indeed the feeling in an odd sort of way, is really going on in public. They are really saying what they're saying, doing what they're doing, meaning what they're meaning. Thought is, in great part anyway, a public activity. (Geertz, quoted in J. Miller, 1983, pp. 202-203)

   10) In Thinking, Everything Needs to Be Made as Simple as Possible

   Everything should be made as simple as possible, but not simpler. (Einstein, quoted in Minsky, 1986, p. 17)

   11) The Conditions for the Construction of Formal Thought

   What, in effect, are the conditions for the construction of formal thought? The child must not only apply operations to objects-in other words, mentally execute possible actions on them-he must also "reflect" those operations in the absence of the objects which are replaced by pure propositions. Thus, "reflection" is thought raised to the second power. Concrete thinking is the representation of a possible action, and formal thinking is the representation of a representation of possible action. . . . It is not surprising, therefore, that the system of concrete operations must be completed during the last years of childhood before it can be "reflected" by formal operations. In terms of their function, formal operations do not differ from concrete operations except that they are applied to hypotheses or propositions [whose logic is] an abstract translation of the system of "inference" that governs concrete operations. (Piaget, quoted in Minsky, 1986, p. 237)

   12) Language Enables the Rehearsal of Thought and, Thereby, Commitment to Long-Term Memory

   [E]ven a human being today (hence, a fortiori, a remote ancestor of contemporary human beings) cannot easily or ordinarily maintain uninterrupted attention on a single problem for more than a few tens of seconds. Yet we work on problems that require vastly more time. The way we do that (as we can observe by watching ourselves) requires periods of mulling to be followed by periods of recapitulation, describing to ourselves what seems to have gone on during the mulling, leading to whatever intermediate results we have reached. This has an obvious function: namely, by rehearsing these interim results . . . we commit them to memory, for the immediate contents of the stream of consciousness are very quickly lost unless rehearsed. . . . Given language, we can describe to ourselves what seemed to occur during the mulling that led to a judgment, produce a rehearsable version of the reaching-a-judgment process, and commit that to long-term memory by in fact rehearsing it. (Margolis, 1987, p. 60)