The rise and fall of logical positivism is the most spectacular story of 20th century philosophy. Logical positivism was wildly successful, and some of its key ideas became widely accepted as common-sense truths among the general public. For instance, people routinely make a sharp distinction between facts and opinions, thinking that this is trite and obvious. They do not realise that they are stating the conclusion of a complex philosophical argument which is fundamentally unsound.
The philosophy of logical positivism was the culmination of centuries of efforts to prove that science was the only valid source of knowledge, while metaphysics and religions were meaningless nonsense. Philosophers called it the “demarcation problem”: how do we draw the boundary line between science and religion? An obvious answer would be that religion requires faith in the unseen — heavens, angels, afterlife, God, while science deals with the real world around us. However, this runs into the problem that science also requires faith in positrons, quasars, gravity, electromagnetic fields, and many other un-observables. The positivists found a solution: we can translate references to un-observables by their observable implications. For example, gravity is not observable, but it implies that planets will have elliptical orbits. According to positivists, when we use the word ‘gravity’, what we really mean is that the planets have elliptical orbits (and all other observable implications of gravity). With this clever philosophical manoeuvre, the positivists showed that despite appearances to the contrary, science does not require faith in the unseen. When scientists talk about electrons, they are just using a shorthand language to describe some rather complex collection of observations that they have made in their laboratories.
Youthful British philosopher A J Ayer went to study the newly emerging philosophy in Vienna, and became an ardent and enthusiastic advocate. One of the key tenets of the philosophy was that sentences were meaningful only if they could be confirmed empirically. Ayer’s exposition of positivism created great excitement. It provided a powerful weapon to modernists, enabling them to attack traditions by asking for an empirical demonstration for all claims. Since no proof could be provided for them, Ayer said that “ethical judgments … have no objective validity — they are (as meaningless as) a cry of pain”. This became widely accepted throughout the academia. Prior to positivism, social scientists had actively engaged in the struggle to improve human welfare. Logical positivism made this an intellectually unrespectable expression of feelings, not suitable for a scientist. To improve their image, social scientists learned to couch passionate advocacy in cold, sterile, and apparently objective language. For example, the intensity of the debate in the Cambridge Capital Controversy baffles observers. Both sides argue using technical and complex mathematical arguments. Neither side drops any hints that the underlying issue is an argument that justifies earnings of capitalists, against Marxist ideas that they exploit workers. As detailed in a previous article, Professor Julie Reuben has explained the damaging effects of this marginalisation of morality on modern university education at book length.
Among philosophers, positivism had a spectacular crash. Many of the central ideas of positivism proved to be indefensible on closer examination. Even the fundamental concept of factual and objectively verifiable could not be sensibly defined. For example, my feeling of happiness is observable to me, and as factual as the sun shining in the sky, but it is not observable and hence subjective to others. Even the lifelong advocate, Ayer, came to realise that positivism was wrong, and said so in a public interview.
The surprising kicker to this story is that the reasons for the philosophers’ rejection of positivism have not been widely understood. Economists in particular, and most social scientists in general, continue to believe in positivist ideas, and to use them as a basis for research. Inertia keeps professionals wedded to this obsolete philosophy, since replacing it would require rejection of 50 years or more of theorising. Nonetheless, a radical re-thinking is the need of the hour, since the positivist rejection of human experience as a source of knowledge has led to impoverished theories in social sciences, which are manifestly incapable of dealing with looming catastrophes on several fronts.
See also RWER blog for more comments and discussion.
see also: Deification of Science and its Disastrous Consequences — to appear in International Journal of Pluralism in Economics Education, 2015
Author: Dr. Asad Zaman, Vice Chancellor at Pakistan Institute of Development Economics
Republished with the permission of the Author.