OVO

One of the most important ingredients of our western civilization is what I may call the ‘rationalist tradition’ which we have inherited from the Greeks. It is the tradition of critical discussion – not for its own sake, but in the interests of the search for truth. Greek science, like Greek philosophy, was one of the products of this tradition, and of the urge to understand the world in which we live, and the tradition founded by Galileo was its renaissance.

Within this rationalist tradition science is valued, admittedly, for its practical achievements; but it is even more highly valued for its informative content, and for its ability to free our minds from old beliefs, old prejudices, and old certainties, and to offer us in their stead new conjectures and daring hypotheses. Science is valued for its liberalizing influence as one of the greatest of the forces that make for human freedom.

According to the view of science which I am trying to defend here, this is due to the fact that scientists have dared (since Thales, Democritus, Plato’s Timaeus, and Aristarchus) to create myths, or conjectures, or theories, which are in striking contrast to the everyday world of common experience, yet able to explain some aspects of this world of common experience. Galileo pays homage to Aristarchus and Copernicus precisely because they dared to go beyond this known world of our senses: “I cannot,” he writes, ”express strongly enough my unbounded admiration for the greatness of mind of these men who conceived [the heliocentric system] and held it to be true [...], in violent opposition to the evidence of their own senses.” This is Galileo’s testimony to the liberalizing force of science. Such theories would be important even if they were no more than exercises for our imagination. But they are more than this, as can be seen from the fact that we submit them to severe tests by trying to deduce from them some of the regularities of the known world of common experience by trying to explain these regularities. And these attempts to explain the known by the unknown (as I have described them elsewhere) have immeasurably extended the realm of the known. They have added to the facts of our everyday world the invisible air, the antipodes, the circulation of the blood, the worlds of the telescope and the microscope, of electricity, and of tracer atoms showing us in detail the movements of matter within living bodies.  All these things are far from being mere instruments: they are witness to the intellectual conquest of our world by our minds.

First published in Contemporary British Philosophy, 3rd Series, ed. H. D. Lewis, 1956. From Conjectures and Refutations. Routledge 1989