Falsificationism

Falsificationism argues that any hypothesis, no matter how respected or time-honored, must be discarded once it is contradicted by new reli-(65) able evidence. This is, of course, an oversimplification, since individual scientists inevitably hold on to their pet theory long after contrary evidence has been found. This is not always a bad thing. Any theory can be made to correspond to the facts, simply by making a few adjustments—called auxiliary hypothesis —so as to bring it into corre-(70) spondence with the accepted observations. The choice of when to reject one theory and accept another is inevitably up to the individual scientist, rather than some methodical law. 

In line 63 the word falsificationism most nearly means... 

Chapter 3 provides an introduction to the identification of mathematical models for reactive systems and an extensive review of the methods for estimating the relevant adjustable parameters. The chapter is initiated with a comparison between Bayesian approach and Poppers falsificationism. The aim is to establish a few fundamental ideas on the reliability of scientific knowledge, which is based on the comparison between alternative models and the experimental results, and is limited by the nonexhaustive nature of the available theories and by the unavoidable experimental errors. 

When the significance and the reliability of the correspondence between theories and experiments are considered, two main alternatives are available. The Standard View, based on the ideas of logical empiricism, assumes that the experiments can confirm a scientific theory, i.e., that they can increase its probability (here intended as logical confidence in its truth, i.e., in its correspondence with the real world). On the contrary, Falsificationism, first proposed by Karl Popper [17], claims that experiments cannot demonstrate the truth of a theory but can only falsify the theory, i.e., demonstrate that a theory is unfit to describe an experimental result. 

Senn SJ (1991) Falsificationism and clinical trials. Statistics in Medicine 10 1679-1692. [SeeCom-ment in Statistics in Medicine 11(9) 1263-1265 (1992)]. 

The central tenets of the falsificationist philosophy of Karl R. Popper are reviewed in detail, and the way they do or do not apply to systematics and phylogeny reconstruction is analyzed. Cladistic analysis, cast in either maximum parsimony or in maximum likelihood approaches, is not compatible with Popperian falsificationism. The main reasons are the absence of a deductive link between a hypothesis of phylogenetic relationships and character distribution on a tree, which translates into the absence of the basic asymmetry of falsification versus verification. This sets Popper s philosophy of science apart from inductive systems. In cladistic analysis, falsification (disconfirmation) is symmetrical to verification (confirmation), which reveals an inductive and hence probabilistic background. The basic problem of systematics as an empirical science resides in character conceptualization and its critical evaluation. 

Popper not only insisted on simple language he also insisted on rationality as the basis for argumentation. To him the rationalist tradition . .. is the tradition of critical discussion — not for its own sake, but in the interest of the search for truth (Popper, 1989 101), truth in this context meaning a regulative principle only (see also Appendix II). Popper equated rationality with the critical attitude. .. (Popper, 1989 248). Given Popper s broad impact on natural sciences and scientists, most systematists probably strive to adopt a critical attitude, a culture of critical discussion, which in a sense represents a weak form of Popper s falsificationism. In that broad sense, modern systematics is — hopefully — Popperian. 

The claim conld be made that systematics can proceed without underlying universal laws, for what is reqnired is nothing bnt a method that allows us to choose a preferred hypothesis from a set of competing hypotheses of relationships relative to some theory such as evolutionary theory. Indeed, we do have a method at our disposal that allows us to do just this, but is it Popperian in its logic The conformity of parsimony analysis with Popper s falsificationism has been asserted in terms of Popper s concepts of logical probability, explanatory power, degrees of corroboration and severity of test. Let us look at these concepts in more detail. 

Popper always emphasized the conventional aspect of the decision that is taken when a basic statement is accepted. Lakatos (1974 12,131) acknowledges that sophisticated methodological falsificationism learned from the conventionalists the importance of decisions... 

Lakatos needs a critical evaluation of theories in his system just as much as Popper, and just like Popper he did not allow ad hoc auxiliary hypotheses that are not independently testable to distort such critical evaluation of competing theories. Both Lakatos and Popper understood hypotheses in the sense of universal propositions and both employed the modus tollens form of argument. Whether the emphasis is on corroboration or falsification, this very distinction cannot be had outside Popper s solution to the logical problem of induction, for it only can provide that very asymmetry, and hence the basis on which to distinguish falsificationism from verificationism. ... 

Comment In Popperian falsificationism, knowledge of the empirical world requires a deductive link between a theory and a singular statement that can be related to an observable state of affairs, given initial conditions. The statement Species are a part of the empirical world requires a (ostensive) concept of species that can be applied to an empirical base (Korner, 1959). Since the attachment of an ostensive concept to an empirical base occurs here and now (hie et nunc), the only ostensive species concept is Mayr s nondimensional species concept (Mayr, 1982). The phylogenetic species concept is a nonostensive concept. 

---