Necessities of Origin and Constitution

The once deeply held conviction that all necessary truths are known a priori is now widely, although by no means universally agreed to have been subjected to penetrating, if not devastating criticism. Scott Soames, for example, on behalf of Saul Kripke, and indirectly of Hilary Putnam, argues that in respect of natural kinds, the introduction of basic essentialist assumptions grounded in our pre-theoretical habits of thinking and speaking – for example, that atomic or molecular structure provides the underlying essence of a substance – allows a sentence like "water = H₂0," in which the identity sign is flanked by rigid designators to express a metaphysically necessary truth. Yet doubts and puzzlement remain over the status of a posteriori necessities, including those relating to an individual's origin. This paper considers some prominent criticisms that have been made of the Kripke–Putnam approach by A. J. Ayer and Frank Ebersole among others and reveals in what respects they are valid, where they are misplaced, and, perhaps more importantly, why the most valuable aspect of this approach can be seen to reflect aspects of our scientific procedures that do indeed point towards an application for a distinction that roughly mirrors that between epistemic and metaphysical possibility, yet one that is grounded instead in the nature of our actual practices.     

Book reviews

Hearing Haggerd, M. P. & Evans, E. F. (Eds.). 1987. British Medical Bulletin, 43 (4), 775-1037. ISBN 0-443-02899-6. £22.50.

Perlmutter, M. (Ed.) (1986). Perspectives on intellectual development : The Minnesota Symposium on Child Psychology. Vol. 19. Hillsdale,NJ: Lawrence Erlbaum Associates, Inc. Pp. 261. ISBN 0-89859-784-6. £19.95.

Ellis, H. D., Jeeves, M. A., Newcombe, F., & Young, A. (Eds.) (1986). Aspects of face processing. Bordrecht : Martinus Nijhoff. Pp. 509. ISBN 90-247-3357-X. £80.25.

Gabrielsson, A. (Ed.) (1987). Action and perception in shythm and music. Stockholm: Royal Swedish Academy of Music. Pp. 237. ISBN 91-85428-51-5.

Dowling, John E. (1987). The Retina. Cambridge, MA, and London :Belknap Press. Pp. xiv + 282. ISBN 0-674-76680-6. $29.95.

Foorman, B. R. & Siegel, A. W. (1986). Acquisition of reading skills : Cultural constraints and cognitive universals. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc. Pp. 168. ISBN 0-89859-642-4. £15.00.

Stillings, N., Feinstein, M., Garfield, J., Rissland, E., Rosenbaum, D., Weisler, S., & Baker-Ward, L. (1987). Cognitive science : An introduction. Cambridge, MA: MIT Press. Pp. 533. ISBN 0-262-19257-8. £22.50.

Kapur, N. (1988). Memory disorders in clinical practice. London:Butterworths. Pp. 289. ISBN 0-407-00712-1. £39.50.

Bussis, A. M., Chittenden, E. A. Amarel, M. & Klausner, E. (1985). Inquiry into meaning: An invetigation of learning to read. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc. Pp. 367. ISBN 0-89859-504-5. £32.95.