In order to assess the tenacity of psychoanalysts in continuing to use a concept of psychic energy, it is advisable to consider whether, as they sometimes claim, the concepts of energy, force, and work in psychoanalysis are akin to those in the natural sciences. Strong disanalogies suggest that the psychoanalytic concepts are quite different and used equivocally even within psychoanalysis. However, they may not be subject to the objections which certain critical psychoanalysts have raised.

On the critical side it is argued that, contrary to a widespread view, the explanation of particular facts does not play a central role in pure science and hence that philosophers of science are misguided in supposing that the understanding of such explanations is one of the central tasks of the philosophy of science. It is suggested that the view being attacked may stem in part from an impression that the establishing of a general law is tantamount to the explanation of particular facts that “fall under” the law. This suggestion effects a bridge to the more positive part of the paper, which consists of an exploration of the complexities exhibited by the relation between the two activities. More specifically, I point out a number of disabilities, any one of which could prevent us from being able to explain particular facts that fall under a given law even after having established the law. Some of these have to do with the form of the law, and some have to do with our powers of detection vis-à-vis the particular facts in question. The former sort have to do with the ways in which laws may deviate from the strict-necessary-and-sufficient-condition ideal. The latter include the following points. (1) The individual explanatory factors may lie beyond our present powers of detection. (2) The complexity of such factors may be too great for us to be able to interrelate them. (3) We may be unable to apply concepts used in the law to facts in this area (although they are in fact applicable).

In this study of Auguste Comte's philosophy of science, an attempt is made to explicate his views on such methodological issues as explanation, prediction, induction and hypothesis. Comte's efforts to resolve the dual problems of demarcation and meaning led to the enunciation of principles of verifiability and predictability. Comte's hypothetico-deductive method is seen to permit conjectures dealing with unobservable entities.

Inductive methods can be used to estimate the accuracies of inductive methods. Call a method immodest if it estimates that it is at least as accurate as any of its rivals. It would be unreasonable to adopt any but an immodest method. Under certain assumptions, exactly one of Carnap's lambda-methods is immodest. This may seem to solve the problem of choosing among the lambda-methods; but sometimes the immodest lambda-method is λ = 0, which it would not be reasonable to adopt. We should therefore reconsider the assumptions that led to this conclusion: for instance, the measure of accuracy.

There are a standard number of replies to the riddle of induction, none of which has gained ascendency. It seems that a new approach is needed that concedes less to the Humean dialectic. Humeans, both traditional and contemporary, unwittingly play on the ambiguity of the phrase “change in the course of nature,” and that is why 'C · ~E' appears to be self-consistent, though in fact it is not. I provide an analysis of 'cause' and ‘natural necessity’ which gives inductive inference that internal warrant we assume it to have in ordinary and scientific thinking and rebut in advance contemporary Humean objections based on the erroneous assumption that ‘x is necessary’ and ‘x is a priori‘ are materially equivalent.