Theoretical simplicity is difficult to characterize, and evidently can depend upon a number of distinct factors. One such desirable characteristic is that the laws of a theory have relatively few "counterinstances" whose accommodation requires the invocation of a ceteris paribus condition and ancillary explanation. It is argued that, when one theory is reduced to another, such that the laws of the second govern the behavior of the parts of the entities in the domain of the first, there is a characteristic (...) gain in simplicity of the sort mentioned: while I see no way of quantitatively measuring the "amount" of defeasibility of the laws of a theory, microreduction can be shown to decrease that "amount.". (shrink)

This paper analyses the traditionally recognized dependence between observation statements and theories. The analysis proceeds by working out the interrelationship between classification systems and theoretical frameworks. Cuvier's and Darwin's theories are used as examples to illustrate this issue. The second part of the paper develops a model designed to give an account of the historical development of this interrelationship. It is argued that the interdependence is not circular and that it is an integral part of scientific research. It is suggested (...) that an interdependence of the type reflected in the model can be helpful in evaluating research programmes in the history of all the sciences. (shrink)

Some philosophers believe that the doctrine that individuals have (nominal) essences is supported by arguments designed to show that proper names have senses. Three such arguments are extracted from recent pieces of philosophy: one from the absurdity of bare particulars, A second from the necessary conditions for identifying bearers of proper names, And a third from the ability to replace proper names in discourse with the help of sortal terms. All three arguments are rejected upon examination. The bearing this rejection (...) has for our conception of how we identify particulars through time is briefly discussed. Finally, An attempt to revive this sort of essentialism vis-A-Vis semantic categories is criticized. (shrink)