Popper on Definitions

Summary  In the present paper I shall first summarize Popper’s criticism of the traditional method of definition, and then go on to comment critically on his own views on the form and function of so-called nominalist definitions.     

Karl Popper,Psychology and Philosophy

This paper intends to re-emphasize the relationship among Psychology, Popper and his Philosophy. Popper, who is often considered as one of the most important philosophers of science, had associations with the discipline of psychology in his early years. Popper was associated with Würzburg school of psychology, especially the psychologies of Külpe, Selz and Bühler. However, there was a change in Popper’s interest from the psychology of discovery to an objectivist epistemology—that is, to the logic of discovery, which he himself acknowledged (1976, p. 55). Popper, not only turned away from psychology, as early as 1930 or thereabouts, he later became one of the most outspoken opponents of a psychological approach to science. This antipathy has worked both ways! Very few psychologists study and discuss Popper. His place in the history of psychology, certainly remains inadequate. But why should psychologists ignore Popper? Instead of turning away from Popper, Psychologists’ efforts should be directed towards bringing into focus Popper, his works and association with psychology. This paper argues and tries to discuss the relationships among Popper, his training in psychology and his philosophy.     

Popper and Synthetic judgements A Priori

Summary  Popper uses the “Humean challenge” as a justification for his falsificationism. It is claimed that in his basic argument he confuses two different doubts: (a) the Humean doubt (Popper’s problem of induction), and (b) the “Popperean” doubt whether – presupposing that there are laws of nature – the laws we accept are in fact valid. Popper’s alleged solution of the problem of induction does not solve the problem in a straightforward way (as Levison and Salmon have remarked before). But if Popper’s solution of the Humean challenge is re-interpreted as being close to Kant’s it makes sense. Even though Popper explicitly rejects Kant’s synthetic judgements a priori, it is claimed here that this is so because he misinterprets Kant’s argument. If he had understood Kant correctly he should have been a modern “Kantianer”!     

Reply to Psarros: Popper and Chemistry

In this article I reply to criticism of my published work by N. Psarros (Journal for the General Philosophy of Science 28: 297–305,1997). I show that I had already answered the first criticism in my published work and not overlooked his supposed refutation. However I offer a plausible argument which he could have used to strengthen his claim. Psarros cites my work on Hopkins in his opening paragraph, but then makes no further reference to it in the text. I indicated to Psarros verbally at Ilkley 1994 (and reiterate the message here) that Hopkins' work on Vitamins is the exemplar of a Popperian historical episode and must require addressing by the opponents of critical rationalism. This revised version was published online in August 2006 with corrections to the Cover Date.     

The structure of analog representation

This paper develops a theory of analog representation. We first argue that the mark of the analog is to be found in the nature of a representational system's interpretation function, rather than in its vehicles or contents alone. We then develop the rulebound structure theory of analog representation, according to which analog systems use interpretive rules that map syntactic structural features onto semantic structural features. The theory involves three degree-theoretic measures that capture three independent ways in which a system can be more or less analog. We explain how our theory improves upon prior accounts of analog representation, provides plausible diagnoses for novel challenge cases, extends to hybrid systems that are partially analog and partially symbolic, and accounts for some of the advantages and disadvantages of representing analogically versus symbolically.     

The mean-integral representation of rectangles

To assess perceptual interaction between the height and width of rectangles, we used an accuracy variant of the Garner paradigm. We measured the discriminability of height and width (baseline tasks) and size and shape (correlated tasks). From thed′ values in these conditions, we estimated perceptual distances and inferred amean-integral representation in which height and width corresponded to nonindependent dimensions in a perceptual space. This model accounted well for performance in these two-stimulus conditions, and it also explained 70% –80% of the decline in performance in selective and divided attention. In a second experiment, conducted for purposes of comparison with the rectangle discrimination Experiment, we studied the discrimination of horizontal and vertical line segments connected in an L-shape. In size discrimination, observers were equally good with line pairs and rectangles, suggesting holistic perception; but in shape discrimination, they appeared to combine information from the two line-pair components of the rectangle independently. The mean-integral model was again successful in relating performance in the Garner tasks quantitatively.     

The internal representation of numbers

A principle of second-order isomorphism asserts that the functional similarities among internal representations parallel the structural similarities among the external objects to which those representations correspond. In accordance with this principle, subjects were asked to rate the similarities of all pairs of the numbers 0 through 9 in each of 24 conditions distinguished by the forms into which they were to be mentally transformed and then judged-including the visual forms of rows of dots and Arabic numerals, the auditory form of spoken English names, and the amodal form of the abstract concepts of the integers themselves. Similarity ratings were found to depend entirely upon the form in which the numbers were to be judged and not at all upon the form in which they were actually presented. Regardless of the form presented, multidimensional scaling solutions for each of the 24 conditions were readily interpretable in terms of structural properties of the form judged-curvature and closure for visual numerals; number of syllables, initial consonant, and vowel phoneme for auditory names; and numerical magnitude, odd-evenness, etc., for abstract concepts. Reanalyses of chronometric data are presented to illustrate how a fuller understanding of human cognitive processes may be attainable by using such structural models of internal representation in conjunction with studies of overt confusion and reaction time.     

The representation of visual scenes

The visual world exists all around us, yet this information must be gleaned through a succession of eye fixations in which high visual acuity is limited to the small foveal region of each retina. In spite of these physiological constraints, we experience a richly detailed and continuous visual world. Research on transsaccadic memory, perception, picture memory and imagination of scenes will be reviewed. Converging evidence suggests that the representation of visual scenes is much more schematic and abstract than our immediate experience would indicate. The visual system may have evolved to maximize comprehension of discrete views at the expense of representing unnecessary detail, but through the action of attention it allows the viewer to access detail when the need arises. This capability helps to maintain the 'illusion' of seeing a rich and detailed visual world at every glance.