Читать книгу Sociology - Anthony Giddens - Страница 70

In 1920s Austria, an influential group of philosophers, known as the Vienna Circle, set out important modifications to Comte’s positivist position. In particular, they tried to clarify what counts as ‘science’ and why the statements scientists make about the world can be accepted as ‘true’. They focused on logic and deductive reasoning rather than simple induction and their approach was described as logical positivism. This recognized that scientists do not go around collecting data and later try to explain what they find (inductive method). Rather, they begin by formulating hypotheses – clearly framed questions or statements about some aspect of reality – and then set out to collect empirical evidence that will verify these (hypothetico-deductive method). To be scientifically valid, they argued, scientific statements and theories always have to be tested against evidence. This is unlike other forms of ‘knowledge’. For example, it is just not possible to say that any particular moral standpoint on poverty or an aesthetic judgement about what is beautiful is ‘true’, however much we debate these subjects. Statements in these fields do not uncover truths about the world and are therefore scientifically meaningless.

Logical positivists adopt a correspondence theory of truth which accepts statements as true only where they ‘correspond’ exactly with what exists in the real world. Hence the key to valid knowledge is empirical verification, and it is the job of scientists constantly to seek out evidence which supports their statements. Logical positivism was highly influential in defining what constitutes a scientific approach to knowledge. But by the late 1930s its central principle of verification was under attack.

Sir Karl Popper (1902–94), a former member of the Vienna Circle, provided the most systematic critique of logical positivism. Popper argued that verification is not a powerful principle, as almost any theory, however unrealistic, can find some evidence that supports its arguments. Verification can never definitively settle theoretical disputes. A much stronger principle is disconfirmation. Broad theories should lead to hypotheses which are, in principle at least, capable of being falsified. Scientists then actively seek out cases that disconfirm or falsify their own hypotheses. In this way, one disconfirming case can tell us much more about the world than thousands of instances of verification ever could (Delanty 1997: 31–2). For instance, we may hypothesize that ‘all swans are white’ and set out to verify this statement. Yet, however many white swans we observe, the hypothesis can never be proved true because non-white swans might still exist. But we need to find just a single black swan in order conclusively to falsify our hypothesis and find a simple truth about the world – not all swans are white.

Karl Popper saw Marxism and Freudian psychoanalysis as unscientific because they offer no criteria for falsification. No amount of verification makes for a solid scientific theory – for instance, no matter how many white swans a researcher might find, it does not rule out the possibility of the existence of a black swan.

Popper suggests that the best hypotheses are not cautious ones but ‘bold conjectures’ which offer the potential for significant knowledge gains. Yet most scientific knowledge is never accepted as universally ‘true’ as it is always open (potentially) to being falsified. In fifty years’ time all black swans may have died out, making our accepted truth about swans (they’re not all white) incorrect. All we can say is that the currently accepted scientific theories and explanations are the best we have because they have not been conclusively falsified – yet. This might appear to be a weak description of science that is at odds with widespread, common-sense ideas of science as producing hard facts and universal laws of nature, but the ‘open’ character of scientific knowledge and the open-mindedness of scientists are both crucial to Popper’s vision. However, in the 1960s and 1970s, detailed work by historians of science called Popper’s version of science into question.