Two dogmas of empiricism, by W. V. Quine.--In defense of a dogma, by H. P. Grice and P. F. Strawson.--The analytic and the synthetic: an untenable dualism, by M. G. White.--Synonymity, by B. Mates.--The meaning of a word, by J. L. Austin.--Meaning and synonymy in natural languages, by R. Carnap.--Analytic-synthetic, by J. Bennett.--On "analytic," by R. M. Martin.--Selected bibliography (p. [188]-196).
Harry Harlow is credited with the discovery of learning set, a process whereby problem solving becomes essentially complete in a single trial of training. Harlow described that process as one that freed his primates from arduous trial-and-error learning. The capacity of the learner to acquire learning sets was in positive association with the complexity and maturation of their brains. It is here argued that Harlow's successful conveyance of learning-set phenomena is of historic significance to the philosophy of psychology. Learning set (...) is said to reflect the affirmation or rejection of hypotheses. Hypotheses are generated by the learner's brain, not its muscles. Thus, learning-set research served to advance the perspective that even nonhuman primates think and that their thinking reflects the active processing of information accrued from efforts to solve problems. Their learning processes are not simply the strengthening of some motor responses over others. Hence, learning-set research served to advance studies of animals as rational agents. This trend is serving to supplant the radical-behavioristic models, formulated earlier this century, with models predicated on rational processes for animals' complex learning and behavior. (shrink)
The Principle that freedom is necessary for moral responsibility (hereafter referred to as “the freedom principle”) has received a variety of explications, but few philosophers have doubted that in some plausible sense it is true. However, two philosophers have recently challenged it using very different but equally ingenious arguments. J.F.M. Hunter has provided the more obviously direct attack in arguing that considerations of freedom as such are in no way relevant to assessments of moral responsibility. Harry Frankfurt has directed his (...) fire at the version of the freedom principle which says that a person is morally responsible for what he has done only if he could have done otherwise. Both Frankfurt and Hunter point out the significance of their arguments for the determinism/moral responsibility debate: if there is no freedom requirement for moral responsibility, then even if determinism threatens freedom, it does not follow that determinism threatens moral responsibility. (shrink)
A recursive enumerator for a function h is an algorithm f which enumerates for an input x finitely many elements including h(x), f is a k(n)-enumerator if for every input x of length n, h(x) is among the first k(n) elements enumerated by f. If there is a k(n)-enumerator for h then h is called k(n)-enumerable. We also consider enumerators which are only A-recursive for some oracle A. We determine exactly how hard it is to enumerate the Kolmogorov function, which (...) assigns to each string x its Kolmogorov complexity: • For every underlying universal machine U, there is a constant a such that C is k(n)-enumerable only if k(n) ≥ n/a for almost all n. • For any given constant k, the Kolmogorov function is k-enumerable relative to an oracle A if and only if A is at least as hard as the halting problem. • There exists an r.e., Turing-incomplete set A such for every non-decreasing and unbounded recursive function k, the Kolmogorov function is k(n)-enumerable relative to A. The last result is obtained by using a relativizable construction for a nonrecursive set A relative to which the prefix-free Kolmogorov complexity differs only by a constant from the unrelativized prefix-free Kolmogorov complexity. Although every 2-enumerator for C is Turing hard for K, we show that reductions must depend on the specific choice of the 2-enumerator and there is no bound on the quantity of their queries. We show our negative results even for strong 2-enumerators as an oracle where the querying machine for any x gets directly an explicit list of all hypotheses of the enumerator for this input. The limitations are very general and we show them for any recursively bounded function g: • For every Turing reduction M and every non-recursive set B, there is a strong 2-enumerator f for g such that M does not Turing reduce B to f. • For every non-recursive set B, there is a strong 2-enumerator f for g such that B is not wtt-reducible to f. Furthermore, we deal with the resource-bounded case and give characterizations for the class ${\rm S}_{2}^{{\rm P}}$ introduced by Canetti and independently Russell and Sundaram and the classes PSPACE, EXP. • ${\rm S}_{2}^{{\rm P}}$ is the class of all sets A for which there is a polynomially bounded function g such that there is a polynomial time tt-reduction which reduces A to every strong 2-enumerator for g. • PSPACE is the class of all sets A for which there is a polynomially bounded function g such that there is a polynomial time Turing reduction which reduces A to every strong 2-enumerator for g. Interestingly, g can be taken to be the Kolmogorov function for the conditional space bounded Kolmogorov complexity. • EXP is the class of all sets A for which there is a polynomially bounded function g and a machine M which witnesses A ∈ PSPACEf for all strong 2-enumerators f for g. Finally, we show that any strong O(log n)-enumerator for the conditional space bounded Kolmogorov function must be PSPACE-hard if P = NP. (shrink)
