Philosophy of Science: Operationalism

Philosophy of Science: Operationalism

Professor Jeffery Kasser produced a series of 36 lectures through The Great Courses entitled Philosophy of Science.

These are my notes, commentary, and synopsis from Kasser’s lectures.  The author of this blog highly recommends this course as a high quality lecture on the philosophy of science.

One may purchase the entire course here.

Operationalism was part of a spectacular attempt, followed by failure, of logical positivism (or logical empiricism).  To understand operationalism, we must first discuss the effect of Einstein on the thinking about science at that time.

The principle of relativity pre-dated Einstein.  If two people are floating in empty space, they are moving with respect to one another without regard to any other objects – any other objects are not needed to define their motion with respect to each other.  A similar principle applies when one is on a ship at sea on smooth waters within a room inside the ship with no windows.  Objects move within that room as if they were in a room on land.  If I were running away from a guy named Jim at 10 miles per hour, and Jim threw a baseball past me at 30 miles per hour, then relative to me, the ball would be moving 20 miles per hour.  This idea worked out fine for all known objects at the time except for one: light.  No matter how fast an object moved, light always appeared to move away from that same object at the same speed in all directions.  The core problem for science at that time was the relativity of all other objects, and the non-relativity of the speed of light. 

Einstein proposed a radical solution to this problem.  He did not ignore the results; he accepted the measurements.  He instructed his peers that they needed to reevaluate core assumptions about space and time.  The mistake was to assume that we had clear ideas about time and length.  Einstein’s solution accepted the data by allowing time and length to expand and contract.  Our mistaken assumptions could be fixed if we focused upon the experience and measurements of the investigation.  This idea of focus upon the measurements and the data had a profound influence upon the scientists of that time.

P. W. Bridgman attempted a solution to this problem in light of Einstein’s proposals.  His solution is called Operationalism.  Operationalism insists that one’s concepts and ideas should never supersede looking directly at nature – looking directly at the measurements and the experiences of the scientific investigation.  We must always ensure that something in nature – something in the experience of the investigation – clearly corresponds to our concepts. 

Operationalism defines scientific concepts in terms of operations we must perform to measure or observe things corresponding to the concept.  Length, for example, is not a property inherent in an object, as one may suppose; but a series of operations or procedures one uses with a device such as a meter stick.  For operationalism, this is all length is – similarly for any other property.  One must also ponder that this also means that all different procedures from measuring the same property are, strictly speaking, different operations; using a meter stick versus using radar are two different definitions of length.  Bridgman proposed that some phenomena are directly observable and need no operational procedure. 

Operationalism has some problems which seem to defy solution.  How does one specify that during the performance of an operational procedure one does not have any additional factors affecting the measurement?  For example, how does one design an operation that eliminates forces of magnetism and radiation pressure for the measurement of an object’s weight upon a balance scale?  There is a strange and open question as to how one can claim that a mercury thermometer and an alcohol thermometer measure the same characteristic of temperature when the operational procedures are not the same.  Another example Kasser points out is the measurement of temperature on the Sun.  We have no measurement device to perform this operation (we are told).  Thus, what we call temperature on the surface of the sun is not an operational definition, but assumes temperature as a concept apart from a measurement device, which is against the point of operationalism.

Brief Commentary

It seems that we cannot get away from abstract concepts.  Many in science claim that it is strictly empirical and focused upon observation and data.  However, even a basic, observable idea such as length is an abstract concept.  One must use abstract reasoning to understand that length measurements of a radar and length measurements of a meter stick have in common the exact same concept of ‘length.’ 

The old Problem of Universals in philosophy has been around for thousands of years, and nobody can get around it, as far as we can tell.  For example, nobody can point in space to a physical object corresponding to the idea of ‘the square root of two.’  One must use non-physical abstract reasoning to understand the square root of two.  And, nobody can provide empirical evidence of the existence of the square root of two.  However, only a strange person would deny the reality of the square root of two.  The same problem seems to apply to science: all its units are abstract ideas.  Empirical claims do not rely strictly on observation.  Science cannot ignore these metaphysical problems.