In this 166 page volume Dr Carlos E. Garcia (2006) articulates a systematic analysis of Karl Popper’s philosophy of science.
Popper’s core catechism is “I may be wrong and you may be right and by an effort we may get closer to the truth”. This is not a slight expression. For one thing by stating firstly “I may be wrong” rather than “I may be right” he assiduously avoids the trap of infinite regress as no reasons are needed to admit error. It is a non-justificationist assertion. Although the assertion about which we may be wrong could be arrived at by any psychological means, Popper avoids psychologism, the effort he is referring to is an effort of logic. Criticism is applied to the conjecture in an attempt to reduce error rather than attempting to confirm. With luck and effort, we may get closer to reality. For Popper there is a reality, non-relative and impersonal, but the inescapable propensity for error prevents us from ever claiming too close a familiarity with same. The notion of truth is timeless, whereas appraisals of corroboration are always indexed to a point in time and a set of accepted test-statements.
Garcia limits his chapter headings to:
2. Solution to the Problem of Induction
5. Verisimilitude, plus a very helpful and concise
Appendix: List of Definitions
As is apparent from the headings, Garcia’s study deals mainly with these cornerstone topics. I recommend the book to both advanced readers and professional philosophy workers. This study is clearly laid out and integrated. Criticisms of Popper over the years have at times been somewhat psychological, criticising him for intemperance towards criticism. He was probably entitled to be testy towards foolish criticism. e.g. Kuhn on one hand absolves him from certain logical sins and then says he may as well have committed them. What defence would work against that? Garcia concludes that Kuhn’s criticism of falsifiability and falsification is inadequate. I recommend that the interested reader carefully test Garcia’s arguments, I think they are strong. Popper, like Schopenhauer, is a lucid writer with an antagonism towards loose argumentation – if one has the patience to follow his trains of thought one might be convinced his was a great mind indeed. Garcia does him justice and I for one have been introduced to fresh perspectives.
Garcia reminds us that Popper considers the distinction between logical probability and corroboration as one of the most interesting findings in the philosophy of knowledge and notes that the logic of probability cannot solve the problem of induction. For Popper, the logical probability of ‘x’ is the probability of ‘x’ relative to some evidence; that is to say, relative to a singular statement or to a finite conjunction of singular statements. Probability gives us information about the chances that an event will occur but it does not inform at all about the severity of the tests that a hypothesis has passed (or failed). Corroboration and degree of corroboration are not equivalent to confirmation and degree of confirmation, or probability, as per Carnap’s logical empiricism. The “probability of a hypothesis”, in the sense of the degree of its corroboration, does not satisfy the laws of the calculus of probability. A highly testable hypothesis is logically improbable.
In Popper’s view science is concerned with intersubjectively testable explanations, a subjective view of probability is problematic. Popper fears that the theory of the probability of hypotheses confuses psychological and logical questions. Is it a probability measure or a plausibility measure? Any unîversal hypothesis goes beyond the empirical evidence. It can be validly tested by seeking counter instances not by collecting supporting examples as this could go on to infinity.
The appendix is instructive for its list of definitions. In this list, Garcia includes the version that he thinks best supports a reading of Popper’s account of science:
Basic statement (also test-statement): a statement that can serve as premise in an empirical falsification.
Corroboration (degree of): the degree to which a hypothesis has stood up to tests.
Event: a set of occurrences of the same kind.
Empirical content (also informative content): The amount of empirical information conveyed by a statement or a theory. Its degree is determined by the ‘size’ of the class of potential falsifiers.
Falsifiability (or testability): the logical relation between a theory and its class of potential falsifiers. Falsifiability is a criterion of the empirical character of a system of statements.
Falsification: the conclusive demonstration that a theory has clashed with a falsifier.
Falsity content (of x): the subclass of false consequences of x. It is not a Tarskian consequence class.
Occurrence: a fact described by a singular (basic) statement.
Logical content (of x): the class of (non-tautological) statements entailed by x, where x can be a statement or a theory. A Tarskian consequence class.
Logical probability (of x): the probability of x relative to some evidence; that is to say, relative to a singular statement or to a finite conjunction of singular statements.
Logical strength: increases with content (or with increasing improbability).
Truth content (of x): the class of (non-tautological) true logical consequences of x. It is a subclass of the logical content.
Verisimilitude (of x): the degree of closeness to the truth of x. It can be measured as the difference of truth content minus falsity content.